In the 17th century, French philosopher René Descartes proposed that only two substances ultimately exist; mind and body. Yet, if the two are entirely distinct, as Descartes believed, how can one substance interact with the other? How, for example, is the intention of a human mind able to cause movement in the person”s limbs? The issue of the interaction between mind and body is known in philosophy as the mind-body problem.
Many fields other than philosophy shares an interest in the nature of mind. In religion, the nature of mind is connected with various conceptions of the soul and the possibility of life after death. In many abstract theories of mind there is considerable overlap between philosophy and the science of psychology. Once part of philosophy, psychology split off and formed a separate branch of knowledge in the 19th century. While psychology used scientific experiments to study mental states and events, philosophy uses reasoned arguments and thought experiments in seeking to understand the concepts that underlie mental phenomena. Also influenced by philosophy of mind is the field of artificial intelligence (AI), which endeavors to develop computers that can mimic what the human mind can do. Cognitive science attempts to integrate the understanding of mind provided by philosophy, psychology, AI, and other disciplines. Finally, all of these fields benefit from the detailed understanding of the brain that has emerged through neuroscience in the late 20th century.
Philosophers use the characteristics of inward accessibility, subjectivity, intentionality, goal-directedness, creativity and freedom, and consciousness to distinguish mental phenomena from physical phenomena.
Perhaps the most important characteristic of mental phenomena is that they are inwardly accessible, or available to us through introspection. We each know our own minds-our sensations, thoughts, memories, desires, and fantasies-in a direct sense, by internal reflection. We also know our mental states and mental events in a way that no one else can. In other words, we have privileged access to our own mental states.
Certain mental phenomena, those we generally call experiences, have a subjective nature-that is, they have certain characteristics we become aware of when we reflect. For instance, there is “something it is like” to feel pain, or have an itch, or see something red. These characteristics are subjective in that they are accessible to the subject of the experience, the person who has the experience, but not to others.
Other mental phenomena, which we broadly refer to as thoughts, have a characteristic philosophers call intentionality. Intentional thoughts are about other thoughts or objects, which are represented as having certain properties or for being related to one another in a certain way. The belief that California is west of Nevada, for example, is about California and Nevada and represents the former for being west of the latter. Although we have privileged access to our intentional states, many of them do not seem to have a subjective nature, at least not in the way that experiences do.
A number of mental phenomena appear to be connected to one another as elements in an intelligent, goal-directed system. The system works as follows: First, our sense organs are stimulated by events in our environment; next, by virtue of these stimulations, we perceive things about the external world; finally, we use this information, as well as information we have remembered or inferred, to guide our actions in ways that further our goals. Goal-directedness seems to accompany only mental phenomena.
Another important characteristic of mind, especially of human minds, is the capacity for choice and imagination. Rather than automatically converting past influences into future actions, individual minds are capable of exhibiting creativity and freedom. For instance, we can imagine things we have not experienced and can act in ways that no one expects or could predict.
Mental phenomena are conscious, and consciousness may be the closest term we have for describing what is special about mental phenomena. Minds are sometimes referred to as consciousness, yet it is difficult to describe exactly what consciousness is. Although consciousness is closely related to inward accessibility and subjectivity, these very characteristics seem to hinder us in reaching an objective scientific understanding of it.
Although philosophers have written about mental phenomena since ancient times, the philosophy of mind did not garner much attention until the work of French philosopher René Descartes in the 17th century. Descartes”s work represented a turning point in thinking about mind by making a strong distinction between bodies and minds, or the physical and the mental. This duality between mind and body, known as Cartesian dualism, has posed significant problems for philosophy ever since.
Descartes believed there are two basic kinds of things in the world, a belief known as substance dualism. For Descartes, the principles of existence for these two groups of things-bodies and minds-are completely different from one another: Bodies exist by being extended in space, while minds exist by being conscious. According to Descartes, nothing can be done to give a body thought and consciousness. No matter how we shape a body or combine it with other bodies, we cannot turn the body into a mind, a thing that is conscious, because being conscious is not a way of being extended.
For Descartes, a person consists of a human body and a human mind causally interacting with one another. For example, the intentions of a human being may cause that person's limbs to move. In this way, the mind can affect the body. In addition, the sense organs of a human being maybe affected by light, pressure, or sound, external sources, which in turn affect the brain, affecting mental states. Thus, the body may affect the mind. Exactly how mind can affect body, and vice versa, is a central issue in the philosophy of mind, and is known as the mind-body problem. According to Descartes, this interaction of mind and body is peculiarly intimate. Unlike the interaction between a pilot and his ship, the connection between mind and body more closely resembles two substances that have been thoroughly mixed together.
In response to the mind-body problem arising from Descartes”s theory of substance dualism, a number of philosophers have advocated various forms of substance monism, the doctrine that there is ultimately just one kind of thing in reality. In the 18th century, Irish philosopher George Berkeley claimed there were no material objects in the world, only minds and their ideas. Berkeley thought that talk about physical objects was simply a way of organizing the flow of experience. Near the turn of the 20th century, American psychologist and philosopher William James proposed another form of substance monism. James claimed that experience is the basic stuff from which both bodies and minds are constructed.
Most philosophers of mind today are substance monists of a third type: They are materialists who believe that everything in the world is basically material, or a physical object. Among materialists, there is still considerable disagreement about the status of mental properties, which are conceived as properties of bodies or brains. Materialists who are property diarists believe that mental properties are an additional kind of property or attribute, not reducible to physical properties. Property dualists have the problem of explaining how such properties can fit into the world envisaged by modern physical science, according to which there are physical explanations for all things.
Materialists who are property monists believe that there is ultimately only one type of property, although they disagree on whether or not mental properties exist in material form. Some property monists, known as reductive materialists, hold that mental properties exist simply as a subset of relatively complex and nonbasic physical properties of the brain. Reductive materialists have the problem of explaining how the physical states of the brain can be inwardly accessible and have a subjective character, as mental states do. Other property monists, known as eliminative materialists, consider the whole category of mental properties to be a mistake. According to them, mental properties should be treated as discredited postulates of an outmoded theory. Eliminative materialism is difficult for most people to accept, since we seem to have direct knowledge of our own mental phenomena by introspection and because we use the general principles we understand about mental phenomena to predict and explain the behavior of others.
Philosophy of mind concerns itself with a number of specialized problems. In addition to the mind-body problem, important issues include those of personal identity, immortality, and artificial intelligence.
During much of Western history, the mind has been identified with the soul as presented in Christian Theology. According to Christianity, the soul is the source of a person”s identity and is usually regarded as immaterial; thus, it is capable of enduring after the death of the body. Descartes”s conception of the mind as a separate, nonmaterial substance fits well with this understanding of the soul. In Descartes”s view, we are aware of our bodies only as the cause of sensations and other mental phenomena. Consequently our personal essence is composed more fundamentally of mind and the preservation of the mind after death would constitute our continued existence.
The mind conceived by materialist forms of substance monism does not fit as neatly with this traditional concept of the soul. With materialism, once a physical body is destroyed, nothing enduring remains. Some philosophers think that a concept of personal identity can be constructed that permits the possibility of life after death without appealing to separate immaterial substances. Following in the tradition of 17th-century British philosopher John Locke, these philosophers propose that a person consists of a stream of mental events linked by memory. It is these links of memory, rather than a single underlying substance, that provides the unity of a single consciousness through time. Immortality is conceivable if we think of these memory links as connecting a later consciousness in heaven with an earlier one on earth.
The field of artificial intelligence also raises interesting questions for the philosophy of mind. People have designed machines that mimic or model many aspects of human intelligence, and there are robots currently in use whose behavior is described in terms of goals, beliefs, and perceptions. Such machines are capable of behavior that, were it exhibited by a human being, would surely be taken to be free and creative. As an example, in 1996 an IBM computer named Deep Blue won a chess game against Russian world champion Garry Kasparov under international match regulations. Moreover, it is possible to design robots that have some sort of privileged access to their internal states. Philosophers disagree over whether such robots truly think or simply appear to think and whether such robots should be considered to be conscious
Dualism, in philosophy, the theory that the universe is explicable only as a whole composed of two distinct and mutually irreducible elements. In Platonic philosophy the ultimate dualism is between “being” and “nonbeing”-that is, between ideas and matter. In the 17th century, dualism took the form of belief in two fundamental substances: mind and matter. French philosopher René Descartes, whose interpretation of the universe exemplifies this belief, was the first to emphasize the irreconcilable difference between thinking substance (mind) and extended substance (matter). The difficulty created by this view was to explain how mind and matter interact, as they apparently do in human experience. This perplexity caused some Cartesians to deny entirely any interaction between the two. They asserted that mind and matter are inherently incapable of affecting each other, and that any reciprocal action between the two is caused by God, who, on the occasion of a change in one, produces a corresponding change in the other. Other followers of Descartes abandoned dualism in favor of monism.
In the 20th century, reaction against the monistic aspects of the philosophy of idealism has to some degree revived dualism. One of the most interesting defenses of dualism is that of Anglo-American psychologist William McDougall, who divided the universe into spirit and matter and maintained that good evidence, both psychological and biological, indicates the spiritual basis of physiological processes. French philosopher Henri Bergson in his great philosophic work Matter and Memory likewise took a dualistic position, defining matter as what we perceive with our senses and possessing in itself the qualities that we perceive in it, such as color and resistance. Mind, on the other hand, reveals itself as memory, the faculty of storing up the past and utilizing it for modifying our present actions, which otherwise would be merely mechanical. In his later writings, however, Bergson abandoned dualism and came to regard matter as an arrested manifestation of the same vital impulse that composes life and mind.
Dualism, in philosophy, the theory that the universe is explicable only as a whole composed of two distinct and mutually irreducible elements. In Platonic philosophy the ultimate dualism is between “being” and “nonbeing-that is, between ideas and matter. In the 17th century, dualism took the form of belief in two fundamental substances: mind and matter. French philosopher René Descartes, whose interpretation of the universe exemplifies this belief, was the first to emphasize the irreconcilable difference between thinking substance (mind) and extended substance (matter). The difficulty created by this view was to explain how mind and matter interact, as they apparently do in human experience. This perplexity caused some Cartesians to deny entirely any interaction between the two. They asserted that mind and matter are inherently incapable of affecting each other, and that any reciprocal action between the two is caused by God, who, on the occasion of a change in one, produces a corresponding change in the other. Other followers of Descartes abandoned dualism in favor of monism.
In the 20th century, reaction against the monistic aspects of the philosophy of idealism has to some degree revived dualism. One of the most interesting defenses of dualism is that of Anglo-American psychologist William McDougall, who divided the universe into spirit and matter and maintained that good evidence, both psychological and biological, indicates the spiritual basis of physiological processes. French philosopher Henri Bergson in his great philosophic work Matter and Memory likewise took a dualistic position, defining matter as what we perceive with our senses and possessing in itself the qualities that we perceive in it, such as color and resistance. Mind, on the other hand, reveals itself as memory, the faculty of storing up the past and utilizing it for modifying our present actions, which otherwise would be merely mechanical. In his later writings, however, Bergson abandoned dualism and came to regard matter as an arrested manifestation of the same vital impulse that composes life and mind.
For many people understanding the place of mind in nature is the greatest philosophical problem. Mind is often though to be the last domain that stubbornly resists scientific understanding and philosophers defer over whether they find that cause for celebration or scandal. The mind-body problem in the modern era was given its definitive shape by Descartes, although the dualism that he espoused is in some form whatever there is a religious or philosophical tradition there is a religious or philosophical tradition whereby the soul may have an existence apart from the body. While most modern philosophers of mind would reject the imaginings that lead us to think that this makes sense, there is no consensus over the best way to integrate our understanding of people as bearers of physical properties lives on the other.
Occasionalism finds from it terms as employed to designate the philosophical system devised by the followers of the 17th-century French philosopher René Descartes, who, in attempting to explain the interrelationship between mind and body, concluded that God is the only cause. The occasionalists began with the assumption that certain actions or modifications of the body are preceded, accompanied, or followed by changes in the mind. This assumed relationship presents no difficulty to the popular conception of mind and body, according to which each entity is supposed to act directly on the other; these philosophers, however, asserting that cause and effect must be similar, could not conceive the possibility of any direct mutual interaction between substances as dissimilar as mind and body.
According to the occasionalists, the action of the mind is not, and cannot be, the cause of the corresponding action of the body. Whenever any action of the mind takes place, God directly produces in connection with that action, and by reason of it, a corresponding action of the body; the converse process is likewise true. This theory did not solve the problem, for if the mind cannot act on the body (matter), then God, conceived as mind, cannot act on matter. Conversely, if God is conceived as other than mind, then he cannot act on mind. A proposed solution to this problem was furnished by exponents of radical empiricism such as the American philosopher and psychologist William James. This theory disposed of the dualism of the occasionalists by denying the fundamental difference between mind and matter.
Generally, along with consciousness, that experience of an external world or similar scream or other possessions, takes upon itself the visual experience or deprive of some normal visual experience, that this, however, does not perceive the world accurately. In its frontal experiment. As researchers reared kittens in total darkness, except that for five hours a day the kittens were placed in an environment with only vertical lines. When the animals were later exposed to horizontal lines and forms, they had trouble perceiving these forms.
Philosophers have long debated the role of experience in human perception. In the late 17th century, Irish philosopher William Molyneux wrote to his friend, English philosopher John Locke, and asked him to consider the following scenario: Suppose that you could restore sight to a person who was blind. Using only vision, would that person be able to tell the difference between a cube and a sphere, which she or he had previously experienced only through touch? Locke, who emphasized the role of experience in perception, thought the answer was no. Modern science actually allows us to address this philosophical question, because a very small number of people who were blind have had their vision restored with the aid of medical technology.
Two researchers, British psychologist Richard Gregory and British-born neurologists” Oliver Sacks, have written about their experiences with men who were blind for a long time due to cataracts and then had their vision restored late in life. When their vision was restored, they were often confused by visual input and were unable to see the world accurately. For instance, they could detect motion and perceive colors, but they had great difficulty with complex stimuli, such as faces. Much of their poor perceptual ability was probably due to the fact that the synapses in the visual areas of their brains had received little or no stimulation throughout their lives. Thus, without visual experience, the visual system does not develop properly.
Visual experience is useful because it creates memories of past stimuli that can later serve as a context for perceiving new stimuli. Thus, you can think of experience as a form of context that you carry around with you. A visual illusion occurs when your perceptual experience of a stimulus is substantially different from the actual stimulus you are viewing. In the previous example, you saw the green circles as different sizes, even though they were actually the same size. To experience another illusion, look at the illustration entitled “Zöllner Illusion.” What shape do you see? You may see a trapezoid that is wider at the top, but the actual shape is a square. Such illusions are natural artifacts of the way our visual systems work. As a result, illusions provide important insights into the functioning of the visual system. In addition, visual illusions are fun to experience.
Consider the pair of illusions in the accompanying illustration, “Illusions of Length.” These illusions are called geometrical illusions, because they use simple geometrical relationships to produce the illusory effects. The first illusion, the Müller-Lyer illusion, is one of the most famous illusions in psychology. Which of the two horizontal lines is longer? Although your visual system tells you that the lines are not equal, a ruler would tell you that they are equal. The second illusion is called the Ponzo illusion. Once again, the two lines do not appear to be equal in length, but they are.
Prevailing states of consciousness, are not as simple, or agreed-upon by any steadfast and held definition of itself, in so, that, consciousness exists. Attempted definitions tend to be tautological (for example, consciousness defined s awareness) or merely descriptive (for example, consciousness described as sensations, thoughts, or feelings). Despite this problem of definition, the subject of consciousness has had a remarkable history. At one time the primary subject matter of psychology, consciousness as an area of study suffered an almost total demise, later reemerging to become a topic of current interest.
René Descartes applied rigorous scientific methods of deduction to his exploration of philosophical questions. Descartes is probably best known for his pioneering work in philosophical skepticism. Author Tom Sorell examines the concepts behind Descartes”s work Meditationes de Prima Philosophia (1641; Meditations on First Philosophy), focusing on its unconventional use of logic and the reactions it aroused. Most of the philosophical discussions of consciousness arose from the mind-body issues posed by the French philosopher and mathematician René Descartes in the 17th century. Descartes asked: Is the mind, or consciousness, independent of matter? Is consciousness extended (physical) or unextended (nonphysical)? Is consciousness determinative, or is it determined? English philosophers such as John Locke equated consciousness with physical sensations and the information they provide, whereas European philosophers such as Gottfried Wilhelm Leibniz and Immanuel Kant gave a more central and active role to consciousness.
The philosopher who most directly influenced subsequent exploration of the subject of consciousness was the 19th-century German educator Johann Friedrich Herbart, who wrote that ideas had quality and intensity and that they may inhibit or facilitate one another. Thus, ideas may pass from “states of reality” (consciousness) to “states of tendency” (unconsciousness), with the dividing line between the two states being described as the threshold of consciousness. This formulation of Herbart clearly presages the development, by the German psychologist and physiologist Gustav Theodor Fechner, of the psychophysical measurement of sensation thresholds, and the later development by Sigmund Freud of the concept of the unconscious.
The experimental analysis of consciousness dates from 1879, when the German psychologist Wilhelm Max Wundt started his research laboratory. For Wundt, the task of psychology was the study of the structure of consciousness, which extended well beyond sensations and included feelings, images, memory, attention, duration, and movement. Because early interest focused on the content and dynamics of consciousness, it is not surprising that the central methodology of such studies was introspection; that is, subjects reported on the mental contents of their own consciousness. This introspective approach was developed most fully by the American psychologist Edward Bradford Titchener at Cornell University. Setting his task as that of describing the structure of the mind, Titchener attempted to detail, from introspective self-reports, the dimensions of the elements of consciousness. For example, taste was “dimensionalized” into four basic categories: sweet, sour, salt, and bitter. This approach was known as structuralism.
By the 1920s, however, a remarkable revolution had occurred in psychology that was to essentially remove considerations of consciousness from psychological research for some 50 years: Behaviorism captured the field of psychology. The main initiator of this movement was the American psychologist John Broadus Watson. In a 1913 article, Watson stated, “I believe that we can write a psychology and never use the term”s consciousness, mental states, mind . . . imagery and the like.” Psychologists then turned almost exclusively to behavior, as described in terms of stimulus and response, and consciousness was totally bypassed as a subject. A survey of eight leading introductory psychology texts published between 1930 and the 1950s found no mention of the topic of consciousness in five texts, and in two it was treated as a historical curiosity.
Beginning in the late 1950s, however, interest in the subject of consciousness returned, specifically in those subjects and techniques relating to altered states of consciousness: sleep and dreams, meditation, biofeedback, hypnosis, and drug-induced states. Much of the surge in sleep and dream research was directly fueled by a discovery relevant to the nature of consciousness. A physiological indicator of the dream state was found: At roughly 90-minute intervals, the eyes of sleepers were observed to move rapidly, and at the same time the sleepers” brain waves would show a pattern resembling the waking state. When people were awakened during these periods of rapid eye movement, they almost always reported dreams, whereas if awakened at other times they did not. This and other research clearly indicated that sleep, once considered a passive state, were instead an active state of consciousness.
During the 1960s, an increased search for “higher levels” of consciousness through meditation resulted in a growing interest in the practices of Zen Buddhism and Yoga from Eastern cultures. A full flowering of this movement in the United States was seen in the development of training programs, such as Transcendental Meditation, that were self-directed procedures of physical relaxation and focused attention. Biofeedback techniques also were developed to bring body systems involving factors such as blood pressure or temperature under voluntary control by providing feedback from the body, so that subjects could learn to control their responses. For example, researchers found that persons could control their brain-wave patterns to some extent, particularly the so-called alpha rhythms generally associated with a relaxed, meditative state. This finding was especially relevant to those interested in consciousness and meditation, and a number of “alpha training” programs emerged.
Another subject that led to increased interest in altered states of consciousness was hypnosis, which involves a transfer of conscious control from the subject to another person. Hypnotism has had a long and intricate history in medicine and folklore and has been intensively studied by psychologists. Much has become known about the hypnotic state, relative to individual suggestibility and personality traits; the subject has now largely been demythologized, and the limitations of the hypnotic state are fairly well known. Despite the increasing use of hypnosis, however, much remains to be learned about this unusual state of focused attention.
Finally, many people in the 1960s experimented with the psychoactive drugs known as hallucinogens, which produce disorders of consciousness. The most prominent of these drugs are lysergic acid diethylamide, or LSD; mescaline, and psilocybin; the latter two have long been associated with religious ceremonies in various cultures. LSD, because of its radical thought-modifying properties, was initially explored for its so-called mind-expanding potential and for its psychotomimetic effects (imitating psychoses). Little positive use, however, has been found for these drugs, and their use is highly restricted.
As the concept of a direct, simple linkage between environment and behavior became unsatisfactory in recent decades, the interest in altered states of consciousness may be taken as a visible sign of renewed interest in the topic of consciousness. That persons are active and intervening participants in their behavior has become increasingly clear. Environments, rewards, and punishments are not simply defined by their physical character. Memories are organized, not simply stored. An entirely new area called cognitive psychologies have emerged that centers on these concerns. In the study of children, increased attention is being paid to how they understand, or perceive, the world at different ages. In the field of animal behavior, researchers increasingly emphasize the inherent characteristics resulting from the way a species has been shaped to respond adaptively to the environment. Humanistic psychologists, with a concern for self-actualization and growth, have emerged after a long period of silence. Throughout the development of clinical and industrial psychology, the conscious states of persons in terms of their current feelings and thoughts were of obvious importance. The role of consciousness, however, was often deemphasized in favor of unconscious needs and motivations. Trends can be seen, however, toward a new emphasis on the nature of states of consciousness.
Perception (psychology), spreads of a process by which organisms interpret and organize sensation to produce a meaningful experience of the world. Sensation usually refers to the immediate, relatively unprocessed result of stimulation of sensory receptors in the eyes, ears, nose, tongue, or skin. Perception, on the other hand, better describes one”s ultimate experience of the world and typically involves further processing of sensory input. In practice, sensation and perception are virtually impossible to separate, because they are part of one continuous process.
Our sense organs translate physical energy from the environment into electrical impulses processed by the brain. For example, light, in the form of electromagnetic radiation, causes receptor cells in our eyes to activate and send signals to the brain. But we do not understand these signals as pure energy. The process of perception allows us to interpret them as objects, events, people, and situations.
Without the ability to organize and interpret sensations, life would seem like a meaningless jumble of colors, shapes, and sounds. A person without any perceptual ability would not be able to recognize faces, understand language, or avoid threats. Such a person would not survive for long. In fact, many species of animals have evolved exquisite sensory and perceptual systems that aid their survival.
Organizing raw sensory stimuli into meaningful experiences involves cognition, a set of mental activities that includes thinking, knowing, and remembering. Knowledge and experience are extremely important for perception, because they help us make sense of the input to our sensory systems. To understand these ideas, try to read the following passage:
You could probably read the text, but not as easily as when you read letters in their usual orientation. Knowledge and experience allowed you to understand the text. You could read the words because of your knowledge of letter shapes, and maybe you even have some prior experience in reading text upside down. Without knowledge of letter shapes, you would perceive the text as meaningless shapes, just as people who do not know Chinese or Japanese see the characters of those languages as meaningless shapes. Reading, then, is a form of visual perception.
Note that as above, whereby you did not stop to read every single letter carefully. Instead, you probably perceived whole words and phrases. You may have also used context to help you figure out what some of the words must be. For example, recognizing the upside may have helped you predict down, because the two words often occur together. For these reasons, you probably overlooked problems with the individual letters-some of them, such as the n in down, are mirror images of normal letters. You would have noticed these errors immediately if the letters were right side up, because you have much more experience seeing letters in that orientation.
How people perceive a well-organized pattern or whole, instead of many separate parts, is a topic of interest in Gestalt psychology. According to Gestalt psychologists, the whole is different from the sum of its parts. Gestalt is a German word meaning configuration or pattern.
The three founders of Gestalt psychology were German researcher’s Max Wertheimer, Kurt Koffka, and Wolfgang Köhler. These men identified a number of principles by which people organize isolated parts of a visual stimulus into groups or whole objects. There are five main laws of grouping: proximity, similarity, continuity, closure, and common fate. A sixth law, that of simplicity, encompasses all of these laws.
Although most often applied to visual perception, the Gestalt laws also apply to perception in other senses. When we listen to music, for example, we do not hear a series of disconnected or random tones. We interpret the music as a whole, relating the sounds to each other based on how similar they are in pitch, how close together they are in time, and other factors. We can perceive melodies, patterns, and form in music. When a song is transposed to another key, we still recognize it, even though all of the notes have changed.
The law of proximity states that the closer objects are to one another, the more likely we are to mentally group them together. In the illustration below, we perceive as groups the boxes that are closest to one another. Note that we do not see the second and third boxes from the left as a pair, because they are spaced farther apart.
The law of similarity leads us to link together parts of the visual field that are similar in color, lightness, texture, shape, or any other quality. That is why, in the following illustration, we perceive rows of objects instead of columns or other arrangements.
The law of continuity leads us to see a line as continuing in a particular direction, rather than making an abrupt turn. In the drawing on the left below, we see a straight line with a curved line running through it. Notice that we do not see the drawing as consisting of the two pieces in the drawing on the right.
According to the law of closure, we prefer complete forms to incomplete forms. Thus, in the drawing below, we mentally close the gaps and perceive a picture of a duck. This tendency allows us to perceive whole objects from incomplete and imperfect forms.
The law of common fate leads us to group together objects that move in the same direction. In the following illustration, imagine that three of the balls are moving in one direction, and two of the balls are moving in the opposite direction. If you saw these in actual motion, you would mentally group the balls that moved in the same direction. Because of this principle, we often see flocks of birds or schools of fish as one unit.
Central to the approach of Gestalt psychologists is the law of prägnanz, or simplicity. This general notions, which encompasses all other Gestalt laws, states that people intuitively prefer the simplest, most stable of possible organizations. For example, look at the illustration below. You could perceive this in a variety of ways: as three overlapping disks; as one whole disk and two partial disks with slices cut out of their right sides; or even as a top view of three-dimensional, cylindrical objects. The law of simplicity states that you will see the illustration as three overlapping disks, because that is the simplest interpretation.
Not only does perception involve organization and grouping, it also involves distinguishing an object from its surroundings. Notice that once you perceive an object, the area around that object becomes the background. For example, when you look at your computer monitor, the wall behind it becomes the background. The object, or figure, is closer to you, and the background, or ground, is farther away.
Gestalt psychologists have devised ambiguous figure-ground relationships-that is, drawings in which the figure and ground can be reversed-to illustrate their point that the whole is different from the sum of its parts. Consider the accompanying illustration entitled “Figure and Ground.” You may see a white vase as the figure, in which case you will see it displayed on a dark ground. However, you may also see two dark faces that point toward one another. Notice that when you do so, the white area of the figure becomes the ground. Even though your perception may alternate between these two possible interpretations, the parts of the illustration are constant. Thus, the illustration supports the Gestalt position that the whole is not determined solely by its parts. The Dutch artist M. C. Escher was intrigued by ambiguous figure-ground relationships.
Although such illustrations may fool our visual systems, people are rarely confused about what they see. In the real world, vases do not change into faces as we look at them. Instead, our perceptions are remarkably stable. Considering that we all experience rapidly changing visual input, the stability of our perceptions is more amazing than the occasional tricks that fool our perceptual systems. How we perceive, a stable world is due, in part, to a number of factors that maintain perceptual constancy.
As we view an object, the image it projects on the retinas of our eyes changes with our viewing distance and angle, the level of ambient light, the orientation of the object, and other factors. Perceptual constancy allows us to perceive an object as roughly the same in spite of changes in the retinal image. Psychologists have identified a number of perceptual consistencies, including lightness constancy, color constancy, shape constancy, and size constancy.
Lightness constancy means that our perception of an object”s lightness or darkness remains constant despite changes in illumination. To understand lightness constancy, try the following demonstration. First, take a plain white sheet of paper into a brightly lit room and note that the paper appears to be white. Then, turn out a few of the lights in the room. Note that the paper continues to appear white. Next, if it will not make the room pitch black, turn out some more lights. Note that the paper appears to be white regardless of the actual amount of light energy that enters the eye.
Lightness constancy illustrates an important perceptual principle: Perception is relative. Lightness constancy may occur because the white piece of paper reflects more light than any of the other objects in the room-regardless of the different lighting conditions. That is, you may have determined the lightness or darkness of the paper relative to the other objects in the room. Another explanation, proposed by 19th-century German physiologist Hermann von Helmholtz, is that we unconsciously take the lighting of the room into consideration when judging the lightness of objects.
Color constancy is closely related to lightness constancy. Color constancy means that we perceive the color of an object as the same despite changes in lighting conditions. You have experienced color constancy if you have ever worn a pair of sunglasses with colored lenses. In spite of the fact that the colored lenses change the color of light reaching your retina, you still perceive white objects as white and red objects as red. The explanations for color constancy parallel those for lightness constancy. One proposed explanation is that because the lenses tint everything with the same color, we unconsciously “subtract” that color from the scene, leaving the original colors.
Another perceptual constancy is shape constancy, which means that you perceive objects as retaining the same shape despite changes in their orientation. To understand shape constancy, hold a book in front of your face so that you are looking directly at the cover. The rectangular nature of the book should be very clear. Now, rotate the book away from you so that the bottom edge of the cover is much closer to you than the top edge. The image of the book on your retina will now be quite different. In fact, the image will now be trapezoidal, with the bottom edge of the book larger on your retina than the top edge. (Try to see the trapezoid by closing one eye and imagining the cover as a two-dimensional shape.) In spite of this trapezoidal retinal image, you will continue to see the book as rectangular. In large measure, shape constancy occurs because your visual system takes depth into consideration.
Depth perception also plays a major role in size constancy, the tendency to perceive objects as staying the same size despite changes in our distance from them. When an object is near to us, its image on the retina is large. When that same object is far away, its image on the retina is small. In spite of the changes in the size of the retinal image, we perceive the object as the same size. For example, when you see a person at a great distance from you, you do not perceive that person as very small. Instead, you think that the person is of normal size and far away. Similarly, when we view a skyscraper from far away, its image on our retina is very small-yet we perceive the building as very large.
Psychologists have proposed several explanations for the phenomenon of size constancy. First, people learn the general size of objects through experience and use this knowledge to help judge size. For example, we know that insects are smaller than people and that people are smaller than elephants. In addition, people take distance into consideration when judging the size of an object. Thus, if two objects have the same retinal image size, the object that seems farther away will be judged as larger. Even infants seem to possess size constancy.
Another explanation for size constancy involves the relative sizes of objects. According to this explanation, we see objects as the same size at different distances because they stay the same size relative to surrounding objects. For example, as we drive toward a stop sign, the retinal image sizes of the stop sign relative to a nearby tree remain constant-both images grow larger at the same rate.
Depth perception is the ability to see the world in three dimensions and to perceive distance. Although this ability may seem simple, depth perception is remarkable when you consider that the images projected on each retina are two-dimensional. From these flat images, we construct a vivid three-dimensional world. To perceive depth, we depend on two main sources of information: binocular disparity, a depth cue that requires both eyes; and monocular cues, which allow us to perceive depth with just one eye.
An autostereogram is a remarkable kind of two-dimensional image that appears three-dimensional (3-D) when viewed in the right way. To see the 3-D image, first make sure you are viewing the expanded version of this picture. Then try to focus your eyes on a point in space behind the picture, keeping your gaze steady. An image of a person playing a piano will appear.
Because our eyes are spaced about 7 cm. (about 3 in.) apart, the left and right retinas receive slightly different images. This difference in the left and right images is called binocular disparity. The brain integrates these two images into a single three-dimensional image, allowing us to perceive depth and distance.
For a demonstration of binocular disparity, fully extend your right arm in front of you and hold up your index finger. Now, alternate closing your right eye and then your left eye while focusing on your index finger. Notice that your finger appears to jump or shift slightly-a consequence of the two slightly different images received by each of your retinas. Next, keeping your focus on your right index finger, hold your left index finger up much closer to your eyes. You should notice that the nearer finger creates a double image, which is an indication to your perceptual system that it is at a different depth than the farther finger. When you alternately close your left and right eyes, notice that the nearer finger appears to jump much more than the more distant finger, reflecting a greater amount of binocular disparity.
You have probably experienced a number of demonstrations that use binocular disparity to provide a sense of depth. A stereoscope is a viewing device that presents each eye with a slightly different photograph of the same scene, which generates the illusion of depth. The photographs are taken from slightly different perspectives, one approximating the view from the left eye and the other representing the view from the right eye. The View-Master, a children”s toy, is a modern type of stereoscope.
Filmmakers have made use of binocular disparity to create 3-D (three-dimensional) movies. In 3-D movies, two slightly different images are projected onto the same screen. Viewers wear special glasses that use colored filters (as for most 3-D movies) or polarizing filters (as for 3-D IMAX movies). The filters separate the image so that each eye receives the image intended for it. The brain combines the two images into a single three-dimensional image. Viewers who watch the film without the glasses see a double image.
Another phenomenon that makes use of binocular disparity is the autostereogram. The autostereogram is a two-dimensional image that can appear three-dimensional without the use of special glasses or a stereoscope. Several different types of autostereograms exist. The most popular, based on the single-image random point at which to point of a stereogram, seemingly becomes three-dimensional when the viewer relaxes or delouses the eyes, as if focusing on a point in space behind the image. The two-dimensional image usually consists of random dots or lines, which, when viewed properly, coalesce into a previously unseen three-dimensional image. This type of autostereogram was first popularized in the Magic Eye series of books in the early 1990s, although its invention traces back too 1979. Most autostereograms are produced using computer software. The mechanism by which autostereograms work is complex, but they employ the same principle as the stereoscope and 3-D movies. That is, each eye receives a slightly different image, which the brain fuses into a single three-dimensional image.
Although binocular disparity is a very useful depth cue, it is only effective over a fairly short range-less than three m (10 ft.). As our distance from objects increases, the binocular disparity decreases-that is, the images received by each retina become more and more similar. Therefore, for distant objects, your perceptual system cannot rely on binocular disparity as a depth cue. However, you can still determine that some objects are nearer and some farther away because of monocular cues about depth.
To portray a realistic three-dimensional world on a two-dimensional canvas, artists must make use of a variety of depth cues. It was not until the 1400s, during the Italian Renaissance, that artists began to understand linear perspective fully and to portray depth convincingly. Shown here are several paintings that produce a sense of depth.
Close one eye and look around you. Notice the richness of depth that you experience. How does this sharp sense of three-dimensionality emerge from input to a single two-dimensional retina? The answer lies in monocular cues, or cues to depth that are effective when viewed with only one eye.
The problem of encoding depth on the two-dimensional retina is quite similar to the problem faced by an artist who wishes to realistically portray depth on a two-dimensional canvas. Some artists are amazingly adept at doing so, using a variety of monocular cues to give their works a sense of depth.
Although there are many kinds of monocular cues, the most important are interposition, atmospheric perspective, texture gradient, linear perspective, size cues, height cues, and motion parallax.
People commonly rely on interposition, or the overlap between objects, to judge distances. When one object partially obscures our view of another object, we judge the covered object as farther away from us.
Probably the most important monocular cue is interposition, or overlap. When one object overlaps or partly blocks our view of another object, we judge the covered object for being farther away from us. This depth cue is all around us-look around you and notice how many objects are partly obscured by other objects. To understand how much we rely on interposition, try this demonstration. Hold two pens, one in each hand, a short distance in front of your eyes. Hold the pens several centimeters apart so they do not overlap, but move one pen just slightly farther away from you than the other. Now close one eye. Without binocular vision, notice how difficult it is to judge which pen is more distant. Now, keeping one eye closed, move your hands closer and closer together until one pen moves in front of the other. Notice how interposition makes depth perception much easier.
When we look out over vast distances, faraway points look hazy or blurry. This effect is known as atmospheric perspective, and it helps us to judge distances. In this picture, the ridges that are farther away appear hazier and less detailed than the closer ridges.
The air contains microscopic particles of dust and moisture that make distant objects look hazy or blurry. This effect is called atmospheric perspective or aerial perspective, and we use it to judge distance. In the anthem, “Oh Canada” it draws reference to the effect of atmospheric perspectives, which make’s distant mountains appear bluish or purple. When you are standing on a mountain, you see brown earth, gray rocks, and green trees and grass-but little that is purple. When you are looking at a mountain from a distance, however, atmospheric particles bend the light so that the rays that reach your eyes lie in the blue or purple part of the color spectrum. This same effect makes the sky appear blue.
An influential American psychologist, James J. Gibson, was among the first people to recognize the importance of texture gradient in perceiving depth. A texture gradient arises whenever we view a surface from a slant, rather than directly from above. Most surfaces-such as the ground, a road, or a field of flowers-have a texture. The texture becomes denser and less detailed as the surface recedes into the background, and this information helps us to judge depth. For example, look at the floor or ground around you. Notice that the apparent texture of the floor changes over distance. The texture of the floor near you appears more detailed than the texture of the floor farther away. When objects are placed at different locations along a texture gradient, judging their distance from you becomes fairly easy.
Linear perspective means that parallel lines, such as the white lines of this road, appear to converge with greater distance and reach a vanishing point at the horizon. We use our knowledge of linear perspective to help us judge distances.
Artists have learned to make great use of linear perspective in representing a three-dimensional world on a two-dimensional canvas. Linear perspective refers to the fact that parallel lines, such as railroad tracks, appear to converge with distance, eventually reaching a vanishing point at the horizon. The more the lines converge, the farther away they appear.
When estimating an object”s distance from us, we take into account the size of its image relative to other objects. This depth cue is known as relative size. In this photograph, because we assume that the airplanes are the same size, we judge the airplanes that take up less of the image for being farther away from the camera.
Another visual cue to apparent depth is closely related to size constancy. According to size constancy, even though the size of the retinal image may change as an object moves closer to us or farther from us, we perceive that object as staying about the same size. We are able to do so because we take distance into consideration. Thus, if we assume that two objects are the same size, we perceive the object that casts a smaller retinal image as farther away than the object that casts a larger retinal image. This depth cue is known as relative size, because we consider the size of an object”s retinal image relative to other objects when estimating its distance.
Another depth cue involves the familiar size of objects. Through experience, we become familiar with the standard size of certain objects, such as houses, cars, airplanes, people, animals, books, and chairs. Knowing the size of these objects helps us judge our distance from them and from objects around them.
When judging an object”s distance, we consider its height in our visual field relative to other objects. The closer an object is to the horizon in our visual field, the farther away we perceive it to be. For example, the wildebeest that are higher in this photograph appear farther away than those that are lower.
We perceive points nearer to the horizon as more distant than points that are farther away from the horizon. This means that below the horizon, objects higher in the visual field appear farther away than those that are lower. Above the horizon, objects lower in the visual field appear farther away than those that are higher. For example, in the accompanying picture entitled “Relative Height,” the animals higher in the photo appear farther away than the animals lower in the photo. But above the horizon, the clouds lower in the photo appear farther away than the clouds higher in the photo. This depth cue is called relative elevation or relative height, because when judging an object”s distance, we consider its height in our visual field relative to other objects.
The monocular cues discussed so far-interposition, atmospheric perspective, texture gradient, linear perspective, size cues, and height cues-are sometimes called pictorial cues, because artists can use them to convey three-dimensional information. Another monocular cue cannot be represented on a canvas. Motion parallax occurs when objects at different distances from you appear to move at different rates when you are in motion. The next time you are driving along in a car, pay attention to the rate of movement of nearby and distant objects. The fence near the road appears to whiz past you, while the more distant hills or mountains appear to stay in virtually the same position as you move. The rate of an object”s movement provides a cue to its distance.
Although motion plays an important role in depth perception, the perception of motion is an important phenomenon in its own right. It allows a baseball outfielder to calculate the speed and trajectory of a ball with extraordinary accuracy. Automobile drivers rely on motion perception to judge the speeds of other cars and avoid collisions. A cheetah must be able to detect and respond to the motion of antelopes, its chief prey, in order to survive.
Initially, you might think that you perceive motion when an object”s image moves from one part of your retina to another part of your retina. In fact, which is what occurs if you are staring straight ahead and a person walks in front of you. Motion perception, however, is not that simple-if it were, the world would appear to move every time we moved our eyes. Keep in mind that you are almost always in motion. As you walk along a path, or simply move your head or your eyes, images from many stationary objects move around on your retina. How does your brain know which movement on the retina is due to your own motion and which is due to motion in the world? Understanding that distinction is the problem that faces psychologists who want to explain motion perception.
One explanation of motion perception involves a form of unconscious inference. That is, when we walk around or move our head in a particular way, we unconsciously expect that images of stationary objects will move on our retina. We discount such movement on the retina as due to our own bodily motion and perceive the objects as stationary.
In contrast, when we are moving and the image of an object does not move on our retina, we perceive that object as moving. Consider what happens as a person moves in front of you and you track that person”s motion with your eyes. You move your head and your eyes to follow the person”s movement, with the result that the image of the person does not move on your retina. The fact that the person”s image stays in roughly the same part of the retina leads you to perceive the person as moving.
Psychologist James J. Gibson thought that this explanation of motion perception was too complicated. He reasoned that perception does not depend on internal thought processes. He thought, instead, that the objects in our environment contain all the information necessary for perception. Think of the aerial acrobatics of a fly. Clearly, the fly is a master of motion and depth perception, yet few people would say the fly makes unconscious inferences. Gibson identified a number of cues for motion detection, including the covering and uncovering of background. Research has shown that motion detection is, in fact, much easier against a background. Thus, as a person moves in front of you, that person first covers and then uncovers portions of the background.
People may perceive motion when none actually exists. For example, motion pictures are really a series of slightly different still pictures flashed on a screen at a rate of 24 pictures, or frames, per second. From this rapid succession of still images, our brain perceives fluid motion-a phenomenon known as stroboscopic movement. For more information about illusions of emotion.
Experience in interacting with the world is vital to perception. For instance, kittens raised without visual experience or deprived of normal visual experience do not perceive the world accurately. In one experiment, researchers reared kittens in total darkness, except that for five hours a day the kittens were placed in an environment with only vertical lines. When the animals were later exposed to horizontal lines and forms, they had trouble perceiving these forms.
Philosophers have long debated the role of experience in human perception. In the late 17th century, Irish philosopher William Molyneux wrote to his friend, English philosopher John Locke, and asked him to consider the following scenario: Suppose that you could restore sight to a person who was blind. Using only vision, would that person be able to tell the difference between a cube and a sphere, which she or he had previously experienced only through touch? Locke, who emphasized the role of experience in perception, thought the answer was no. Modern science actually allows us to address this philosophical question, because a very small number of people who were blind have had their vision restored with the aid of medical technology.
Two researchers, British psychologist Richard Gregory and British-born neurologist Oliver Sacks, have written about their experiences with men who were blind for a long time due to cataracts and then had their vision restored late in life. When their vision was restored, they were often confused by visual input and were unable to see the world accurately. For instance, they could detect motion and perceive colors, but they had great difficulty with complex stimuli, such as faces. Much of their poor perceptual ability was probably due to the fact that the synapses in the visual areas of their brains had received little or no stimulation throughout their lives. Thus, without visual experience, the visual system does not develop properly.
Visual experience is useful because it creates memories of past stimuli that can later serve as a context for perceiving new stimuli. Thus, you can think of experience as a form of context that you carry around with you.
Ordinarily, when you read, you use the context of your prior experience with words to process the words you are reading. Context may also occur outside of you, as in the surrounding elements in a visual scene. When you are reading and you encounter an unusual word, you may be able to determine the meaning of the word by its context. Your perception depends on the context.
Although context is useful most of the time, on some rare occasions context can lead you to misperceive a stimulus. Look at Example B in the “Context Effects” illustration. Which of the green circles is larger? You may have guessed that the green circle on the right is larger. In fact, the two circles are the same size. Your perceptual system was fooled by the context of the surrounding red circles.
Against a background of slanted lines, a perfect square appears trapezoidal-that is, wider at the top than at the bottom. This illusion may occur because the lines create a sense of depth, making the top of the square seem farther away and larger.
A visual illusion occurs when your perceptual experience of a stimulus is substantially different from the actual stimulus you are viewing. In the previous example, you saw the green circles as different sizes, even though they were actually the same size. To experience another illusion, look at the illustration entitled “Zöllner Illusion.” What shape do you see? You may see a trapezoid that is wider at the top, but the actual shape is a square. Such illusions are natural artifacts of the way our visual systems work. As a result, illusions provide important insights into the functioning of the visual system. In addition, visual illusions are fun to experience.
An ascribing notion to awaiting the idea that something debated finds to its intent of meaning the explicit significance of the same psychology that is immeasurably the scientific study of behavior and the mind. This definition contains three elements. The first is that psychology is a scientific enterprise that obtains knowledge through systematic and objective methods of observation and experimentation. Second is that psychologists study behavior, which refers to any action or reaction that can be measured or observed-such as the blink of an eye, an increase in heart rate, or the unruly violence that often erupts in a mob. Third is that psychologists study the mind, which refers to both conscious and unconscious mental states. These states cannot actually be seen, only inferred from observable behavior.
Many people think of psychologists as individuals who dispense advice, analyze personality, and help those who are troubled or mentally ill. But psychology is far more than the treatment of personal problems. Psychologists strive to understand the mysteries of human nature-why people think, feel, and act as they do. Some psychologists also study animal behavior, using their findings to determine laws of behavior that apply to all organisms and to formulate theories about how humans behave and think.
With its broad scope, psychology investigates an enormous range of phenomena: learning and memory, sensation and perception, motivation and emotion, thinking and language, personality and social behavior, intelligence, infancy and child development, mental illness, and much more. Furthermore, psychologists examine these topics from a variety of complementary perspectives. Some conduct detailed biological studies of the brain, others explore how we process information; others analyze the role of evolution, and still others study the influence of culture and society.
Psychologists seek to answer a wide range of important questions about human nature: Are individuals genetically predisposed at birth to develop certain traits or abilities? How accurate are people at remembering faces, places, or conversations from the past? What motivates us to seek out friends and sexual partners? Why do so many people become depressed and behave in ways that seem self-destructive? Do intelligence test scores predict success in school, or later in a career? What causes prejudice, and why is it so widespread? Can the mind be used to heal the body? Discoveries from psychology can help people understand themselves, relate better to others, and solve the problems that confront them.
The term psychology comes from two Greek words: psyche, which means “soul,” and logos, "the study of." These root words were first combined in the 16th century, at a time when the human soul, spirit, or mind was seen as distinct from the body.
Psychology overlaps with other sciences that investigate behavior and mental processes. Certain parts of the field share much with the biological sciences, especially physiology, the biological study of the functions of living organisms and their parts. Like physiologists, many psychologists study the inner workings of the body from a biological perspective. However, psychologists usually focus on the activity of the brain and nervous system.
The social sciences of sociology and anthropology, which study human societies and cultures, also intersect with psychology. For example, both psychology and sociology explore how people behave when they are in groups. However, psychologists try to understand behavior from the vantage point of the individual, whereas sociologists focus on how behavior is shaped by social forces and social institutions. Anthropologists investigate behavior as well, paying particular attention to the similarities and differences between human cultures around the world.
Psychology is closely connected with psychiatry, which is the branch of medicine specializing in mental illnesses. The study of mental illness is one of the largest areas of research in psychology. Psychiatrists and psychologists differ in their training. A person seeking to become a psychiatrist first obtains a medical degree and then engages in further formal medical education in psychiatry. Most psychologists have a doctoral graduate degree in psychology.
The study of psychology draws on two kinds of research: basic and applied. Basic researchers seek to test general theories and build a foundation of knowledge, while applied psychologists study people in real-world settings and use the results to solve practical human problems. There are five major areas of research: biopsychology, clinical psychology, cognitive psychology, developmental psychology, and social psychology. Both basic and applied research is conducted in each of these fields of psychology.
This section describes basic research and other activities of psychologists in the five major fields of psychology. Applied research is discussed in the Practical Applications of Psychology section of this article.
Magnetic resonance imaging (MRI) reveals structural differences between a normal adult brain, left, and the brain of a person with schizophrenia, right. The schizophrenic brain has enlarged ventricles (fluid-filled cavities), shown in light gray. However, not all people with schizophrenia show this abnormality.
How do body and mind interact? Are body and mind fundamentally different parts of a human being, or are they one and the same, interconnected in important ways? Inspired by this classic philosophical debate, many psychologists specialize in biopsychology, the scientific study of the biological underpinnings of behavior and mental processes.
At the heart of this perspective is the notion that human beings, like other animals, have an evolutionary history that predisposes them to behave in ways that are uniquely adaptive for survival and reproduction. Biopsychologists work in a variety of subfields. Researchers in the field of ethology observe fish, reptiles, birds, insects, primates, and other animal species in their natural habitats. Comparative psychologists study animal behavior and make comparisons among different species, including humans. Researchers in evolutionary psychology theorize about the origins of human aggression, altruism, mate selection, and other behaviors. Those in behavioral genetics seek to estimate the extent to which human characteristics such as personality, intelligence, and mental illness are inherited.
Particularly important to biopsychology is a growing body of research in behavioral neuroscience, the study of the links between behavior and the brain and nervous system. Facilitated by computer-assisted imaging techniques that enable researchers to observe the living human brain in action, this area is generating great excitement. In the related area of cognitive neuroscience, researchers record physical activity in different regions of the brain as the subject reads, speaks, solves math problems, or engages in other mental tasks. Their goal is to pinpoint activities in the brain that correspond to different operations of the mind. In addition, many Biopsychologists are involved in psychopharmacology, the study of how drugs affect mental and behavioral functions.
This chart illustrates the percentage of people in the United States who experience a particular mental illness at some point during their lives. The figures are derived from the National Comorbidity Survey, in which researchers interviewed more than 8000 people aged 15 to 54 years. Homeless people and those living in prisons, nursing homes, or other institutions were not included in the survey.
Clinical psychology is dedicated to the study, diagnosis, and treatment of mental illnesses and other emotional or behavioral disorders. More psychologists work in this field than in any other branch of psychology. In hospitals, community clinics, schools, and in private practice, they use interviews and tests to diagnose depression, anxiety disorders, schizophrenia, and other mental illnesses. People with these psychological disorders often suffer terribly. They experience disturbing symptoms that make it difficult for them to work, relate to others, and cope with the demands of everyday life.
Over the years, scientists and mental health professionals have made great strides in the treatment of psychological disorders. For example, advances in psychopharmacology have led to the development of drugs that relieve severe symptoms of mental illness. Clinical psychologists usually cannot prescribe drugs, but they often work in collaboration with a patient”s physician. Drug treatment is often combined with psychotherapy, a form of intervention that relies primarily on verbal communication to treat emotional or behavioral problems. Over the years, psychologists have developed many different forms of psychotherapy. Some forms, such as psychoanalysis, focus on resolving internal, unconscious conflicts stemming from childhood and past experiences. Other forms, such as cognitive and behavioral therapies, focus more on the person”s current level of functioning and try to help the individual change distressing thoughts, feelings, or behaviors.
In addition to studying and treating mental disorders, many clinical psychologists study the normal human personality and the ways in which individuals differ from one another. Still, others administer a variety of psychological tests, including intelligence tests and personality tests. These tests are commonly given to individuals in the workplace or in school to assess their interests, skills, and level of functioning. Clinical psychologists also use tests to help them diagnose people with different types of psychological disorders.
The field of counseling psychology is closely related to clinical psychology. Counseling psychologists may treat mental disorders, but they more commonly treat people with less-severe adjustment problems related to marriage, family, school, or career. Many other types of professionals care for and treat people with psychological disorders, including psychiatrists, psychiatric social workers, and psychiatric nurses.
To take the Stroop test, name aloud each color in the two columns at left as quickly as you can. Next, look at the right side of the illustration and quickly name the colors in which the words are printed. Which task took longer to complete? The test, devised in 1935 by American psychologist John Stroop, shows that people cannot help but process word meanings, and that this processing interferes with the color-naming task.
How do people learn from experience? How and where in the brain are visual images, facts, and personal memories stored? What causes forgetting? How do people solve problems or make difficult life decisions? Does language limit the way people think? And to what extent are people influenced by information outside of conscious awareness?
These are the kinds of questions posed within cognitive psychology, the scientific study of how people acquire, process, and utilize information. Cognition refers to the process of knowing and encompasses nearly the entire range of conscious and unconscious mental processes: sensation and perception, conditioning and learning, attention and consciousness, sleep and dreaming, memory and forgetting, reasoning and decision making, imagining, problem solving, and language.
Decades ago, the invention of digital computers gave cognitive psychologists a powerful new way of thinking about the human mind. They began to see human beings as information processors who receive input, process and store information, and produce output. This approach became known as the information-processing model of cognition. As computers have become more sophisticated, cognitive psychologists have extended the metaphor. For example, most researchers now reject the idea that information is processed in linear, sequential steps. Instead they find that the human mind is capable of parallel processing, in which multiple operations are carried out simultaneously.
In this information-processing model of memory, information that enters the brain is briefly recorded in sensory memory. If we focus our attention on it, the information may become part of working memory (also called short-term memory), where it can be manipulated and used. Through encoding techniques such as repetition and rehearsal, information may be transferred to long-term memory. Retrieving long-term memories makes them active again in working memory.
Are people programmed by inborn biological dispositions? Or is an individual”s fate molded by culture, family, peers, and other socializing influences within the environment? These questions about the roles of nature and nurture are central to the study of human development.
An incredibly complex array of influences, including families, acquaintances, mass media, and society as a whole, help determine the moral development of children. Although a rash of violent incidents in American schools in the late 1990s focused attention on deviant youth behavior, the vast majority of children seem to function harmoniously with others. In this August 1999 article from Scientific American, William Damon, director of the Center on Adolescence at Stanford University in California, explores recent findings on how young people develop morality.
Developmental psychology focuses on the changes that come with age. By comparing people of different ages, and by tracking individuals over time, researchers in this area study the ways in which people mature and change over the life span. Within this area, those who specialize in child development or child psychology study physical, intellectual, and social development in fetuses, infants, children, and adolescents. Recognizing that human development is a lifelong process, other developmental psychologists study the changes that occur throughout adulthood. Still others specialize in the study of old age, even the process of dying.
A “shock generator,” top, was used by American psychologist Stanley Milgram in experiments designed to test the obedience of people to authority. An experimenter instructed subjects to administer what they believed were painful electric shocks to Mr. Wallace, bottom, an accomplice of the experimenter who was strapped into a chair and connected to the generator by electrodes on his skin. No actual shocks occurred. The experimenter ordered the subjects to continue as the shocks increased to a level the subjects believed were dangerous or even lethal. In Milgram”s initial study, 65 percent of people obeyed the experimenter and delivered the maximum shock of 450 volts. Milgram discusses his conclusions in this sound clip.
Social psychology is the scientific study of how people think, feel, and behave in social situations. Researchers in this field ask questions such as, How do we form impressions of others? How are people persuaded to change their attitudes or beliefs? What causes people to conform with group situations? What leads someone to help or ignore a person in need? Under what circumstances do people obey or resist orders?
By observing people in real-world social settings, and by carefully devising experiments to test people”s social behavior, social psychologists learn about the ways people influence, perceive, and interact with one another. The study of social influence includes topics such as conformity, obedience to authority, the formation of attitudes, and the principles of persuasion. Researchers interested in social perception study how people come to know and evaluate one another, how people form group stereotypes, and the origins of prejudice. Other topics of particular interest to social psychologists include physical attraction, love and intimacy, aggression, altruism, and group processes. Many social psychologists are also interested in cultural influences on interpersonal behavior.
Whereas basic researchers test theories about mind and behavior, applied psychologists are motivated by a desire to solve practical human problems. Four particularly active areas of application are health, education, business, and law.
Today, many psychologists work in the emerging area of health psychology, the application of psychology to the promotion of physical health and the prevention and treatment of illness. Researchers in this area have shown that human health and well-being depends on both biological and psychological factors.
Many psychologists in this area study psychophysiological disorders (also called psychosomatic disorders), conditions that are brought on or influenced by psychological states, most often stress. These disorders include high blood pressure, headaches, asthma, and ulcers. Researchers have discovered that chronic stress is associated with an increased risk of coronary heart disease. In addition, stress can compromise the body”s immune system and increase susceptibility to illness.
Health psychologists also study how people cope with stress. They have found that people who have family, friends, and other forms of social support are healthier and live longer than those who are more isolated. Other researchers in this field examine the psychological factors that underlie smoking, drinking, drug abuse, risky sexual practices, and other behaviors harmful to health.
Psychologists in all branches of the discipline contribute to our understanding of teaching, learning, and education. Some help develop standardized tests used to measure academic aptitude and achievement. Others study the ages at which children become capable of attaining various cognitive skills, the effects of rewards on their motivation to learn, computerized instruction, bilingual education, learning disabilities, and other relevant topics. Perhaps the best-known application of psychology to the field of education occurred in 1954 when, in the case of Brown v Board of Education, the Supreme Court of the United States outlawed the segregation of public schools by race. In its ruling, the Court cited psychological studies suggesting that segregation had a damaging effect on black students and tended to encourage prejudice.
In addition to the contributions of psychology as a whole, two fields within psychology focus exclusively on education: educational psychology and school psychology. Educational psychologists seek to understand and improve the teaching and learning process within the classroom and other educational settings. Educational psychologists study topics such as intelligence and ability testing, student motivation, discipline and classroom management, curriculum plans, and grading. They also test general theories about how students learn most effectively. School psychologists work in elementary and secondary school systems administering tests, making placement recommendations, and counseling children with academic or emotional problems.
The business world, psychology is applied in the workplace and in the marketplace. Industrial-organizational (I-O) psychology focuses on human behavior in the workplace and other organizations. I-O psychologists conduct research, teach in business schools or universities, and work in private industry. Many I-O psychologists study the factors that influence worker motivation, satisfaction, and productivity. Others study the personal traits and situations that foster great leadership. Still, others focus on the processes of personnel selection, training, and evaluation. Studies have shown, for example, that face-to-face interviews sometimes result in poor hiring decisions and may be biased by the applicant's gender, race, and physical attractiveness. Studies have also shown that certain standardized tests can help to predict on-the-job performance.
Consumer psychology is the study of human decision making and behavior in the marketplace. In this area, researchers analyze the effects of advertising on consumers attitudes and buying habits. Consumer psychologists also study various aspects of marketing, such as the effects of packaging, price, and other factors that lead people to purchase one product rather than another.
Many psychologists today work in the legal system. They consult with attorneys, testify in court as expert witnesses, counsel prisoners, teach in law schools, and research various justice-related issues. Sometimes referred to as forensic psychologists, those who apply psychology to the law study a range of issues, including jury selection, eyewitness testimony, confessions to police, lie-detector tests, the death penalty, criminal profiling, and the insanity defense.
Studies in forensic psychology have helped to illuminate weaknesses in the legal system. For example, based on trial-simulation experiments, researchers have found that jurors are often biased by various facts not in evidence-that is, facts the judge tells them to disregard. In studying eyewitness testimony, researchers have staged mock crimes and asked witnesses to identify the assailant or recall other details. These studies have revealed that under certain condition’s eyewitnesses are highly prone to error.
Psychologists in this area often testify in court as expert witnesses. In cases involving the insanity defense, forensic clinical psychologists are often called to court to give their opinion about whether individual defendants are sane or insane. Used as a legal defense, insanity means that defendants, because of a mental disorder, cannot appreciate the wrongfulness of their conduct or control it. Defendants who are legally insane at the time of the offense may be absolved of criminal responsibility for their conduct and judged not guiltily. Psychologists are often called to testify in court on other controversial matters as well, including the accuracy of eyewitness testimony, the mental competence (fitness) of defendants to stand trial, and the reliability of early childhood memories.
Psychology has applications in many other domains of human life. Environmental psychologists focus on the relationship between people and their physical surroundings. They study how street noise, heat, architectural design, population density, and crowding affect people”s behavior and mental health. In a related field, human factor’s psychologists work on the design of appliances, furniture, tools, and other manufactured items in order to maximize their comfort, safety, and convenience. Sports psychologists advise athletes and study the physiological, perceptual-motor, motivational, developmental, and social aspects of athletic performance. Other psychologists specialize in the study of political behavior, religion, sexuality, or behavior in the military.
Psychologists from all areas of specialization use the scientific method to test their theories about behavior and mental processes. A theory is an organized set of principles that is designed to explain and predict some phenomenon. Good theories also provide specific testable predictions, or hypotheses, about the relation between two or more variables. Formulating a hypothesis to be tested is the first important step in conducting research.
Over the years, psychologists have devised numerous ways to test their hypotheses and theories. Many studies are conducted in a laboratory, usually located at a university. The laboratory setting allows researchers to control what happens to their subjects and make careful and precise observations of behavior. For example, a psychologist who studies memory can bring volunteers into the lab, ask them to memorize a list of words or pictures, and then test their recall of that material seconds, minutes, or days later.
As indicated by the term field research, studies may also be conducted in real-world locations. For example, a psychologist investigating the reliability of eyewitness testimony might stage phony crimes in the street and then ask unsuspecting bystanders to identify the culprit from a set of photographs. Psychologists observe people in a wide variety of other locations outside the laboratory, including classrooms, offices, hospitals, college dormitories, bars, restaurants, and prisons.
In both laboratory and field settings, psychologists conduct their research using a variety of methods. Among the most common methods are archival studies, case studies, surveys, naturalistic observations, correlational studies, experiments, literature reviews, and measures of brain activity.
One way to learn about people is through archival studies, an examination of existing records of human activities. Psychological researchers often examine old newspaper stories, medical records, birth certificates, crime reports, popular books, and artwork. They may also examine statistical trends of the past, such as crime rates, birth rates, marriage and divorce rates, and employment rates. The strength of such measures is that by observing people only secondhand, researchers cannot unwittingly influence the subjects by their presence. However, available records of human activity are not always complete or detailed enough to be useful.
Archival studies are particularly valuable for examining cultural or historical trends. For example, in one study of physical attractiveness, researchers wanted to know if American standards of female beauty have changed over several generations. These researchers looked through two popular women”s magazines between 1901 and 1981 and examined the measurements of the female models. They found that “curvaceousness” (as measured by the bust-to-waist ratio) varied over time, with a boyish, slender look considered desirably in some time periods but not in others.
Sometimes psychologists interview, test, observe, and investigate the backgrounds of specific individuals in detail. Such case studies are conducted when researchers believe that an in-depth look at one individual will reveal something important about people in general.
Case studies often take a great deal of time to complete, and the results may be limited by the fact that the subject is atypical. Yet case studies have played a prominent role in the development of psychology. Austrian physician Sigmund Freud based his theory of psychoanalysis on his experiences with troubled patients. Swiss psychologist Jean Piaget first began to formulate a theory of intellectual development by questioning his own children. Neuroscientists learn about how the human brain works by testing patients who have suffered brain damage. Cognitive psychologists learn about human intelligence by studying child prodigies and other gifted individuals. Social psychologists learn about group decision making by analyzing the policy decisions of government and business groups. When an individual is exceptional in some way, or when a hypothesis can be tested only through intensive, long-term observation, the case study is a valuable method.
An electroencephalogram, or EEG, is a recording of the action potential, or electrical, activity of the cerebral cortex of the brain. An EEG is made by attaching electrodes to the scalp, then collecting, amplifying, and recording the electrical impulses of the brain.
Biopsychologists interested in the links between brain and behavior use a variety of specialized techniques in their research. One approach is to observe and test patients who have suffered damage to a specific region of the brain to determine what mental functions and behaviors were affected by that damage. British-born neurologist Oliver Sacks has written several books in which he describes case studies of brain-damaged patients who exhibited specific deficits in their speech, memory, sleep, and even in their personalities.
This positron emission tomography (PET) scan of the brain shows the activity of brain cells in the resting state and during three types of auditory stimulation. PET uses radioactive substances introduced into the brain to measure such brain functions as cerebral metabolism, blood flow and volume, oxygen use, and the formation of neurotransmitters. This imaging method collects data from many different angles, feeding the information into a computer that produces a series of cross-sectional images.
A second approach is too physically altar the brain and measure the effects of that change on behavior. The alteration can be achieved in different ways. For example, animal researchers often damage or destroy a specific region of a laboratory animal's brain through surgery. Other researchers might spark or inhibit activity in the brain through the use of drugs or electrical stimulation.
This magnetic resonance imaging (MRI) scan of a normal adult head shows the brain, airways, and soft tissues of the face. The large cerebral cortex, appearing in yellow and green, forms the bulk of the brain tissue; the circular cerebellum, center left, in red, and the elongated brainstem, center, in red, are also prominently shown.
Another way to study the relationship between the brain and behavior is to record the activity of the brain with machines while a subject engages in certain behaviors or activities. One such instrument is the electroencephalograph, a device that can detect, amplify, and record the level of electrical activity in the brain by means of metal electrodes taped to the scalp.
Advances in technology in the early 1970s allowed psychologists to see inside the living human brain for the first time without physically cutting into it. Today, psychologists use a variety of sophisticated brain-imaging techniques. The computerized axial tomography (CT or CAT) scan provides a computer-enhanced X-ray image of the brain. The more advanced positron emission tomography (PET) scan tracks the level of activity in specific parts of the brain by measuring the amount of glucose being used there. These measurements are then fed to a computer, which produces a color-coded image of brain activity. Another technique is magnetic resonance imaging (MRI), which produces high-resolution cross-sectional images of the brain. A high-speed version of MRI known as functional MRI produces moving images of the brain as its activity changes in real time. These relatively new brain imaging techniques have generated great excitement, because they allow researchers to identify parts of the brain that are active while people read, speak, listen to music, solve math problems, and engage in other mental activities.
In contrast with the in-depth study of one person, surveys describe a specific population or group of people. Surveys involve asking people a series of questions about their behaviors, thoughts, or opinions. Surveys can be conducted in person, over the phone, or through the mail. Most surveys study a specific group-for example, college students, working mothers, men, or homeowners. Rather than questioning every person in the group, survey researchers choose a representative sample of people and generalize the findings to the larger population.
Surveys may pertain to almost any topic. Often surveys ask people to report their feelings about various social and political issues, the TV shows they watch, or the consumers’ products they purchase. Surveys are also used to learn about people”s sexual practices; to estimate the use of cigarettes, alcohol, and other drugs; and to approximate the proportion of people who experience feelings of life satisfaction, loneliness, and other psychological states that cannot be directly observed.
Surveys must be carefully designed and conducted to ensure their accuracy. The results can be influenced, and biased, by two factors: who the respondents are and how the questions are asked. For a survey to be accurate, the sample being questioned must be representative of the population on key characteristics such as sex, race, age, region, and cultural background. To ensure similarity to the larger population, survey researchers usually try to make sure that they have a random sample, a method of selection in which everyone in the population has an equal chance of being chosen.
When the sample is not random, the results can be misleading. For example, prior to the 1936 United States presidential election, pollsters for the magazine Literary Digest mailed postcards to more than 10 million people who were listed in telephone directories or as registered owners of automobiles. The cards asked for whom they intended to vote. Based on the more than 2 million ballots that were returned, the Literary Digest predicted that Republican candidate Alfred M. Landon would win in a landslide over Democrat Franklin D. Roosevelt. At the time, however, more Republicans than Democrats owned telephones and automobiles, skewing the poll results. In the election, Landon won only two states.
The results of survey research can also be influenced by the way that questions are asked. For example, when asked about “welfare,” a majority of Americans in one survey said that the government spends too much money. But when asked about “assistance to the poor,” significantly fewer people gave this response.
In naturalistic observation, the researcher observes people as they behave in the real world. The researcher simply records what occurs and does not intervene in the situation. Psychologists use naturalistic observation to study the interactions between parents and children, doctors and patients, police and citizens, and managers and workers.
Naturalistic observation is common in anthropology, in which field workers seek to understand the everyday life of a culture. Ethologists, who study the behavior of animals in their natural habitat, also use this method. For example, British ethologist Jane Goodall spent many years in African jungles observing chimpanzees-their social structure, courting rituals, struggles for dominance, eating habits, and other behaviors. Naturalistic observation is also common among developmental psychologists who study social play, parent-child attachments, and other aspects of child development. These researchers observe children at home, in school, on the playground, and in other settings.
Case studies, surveys, and naturalistic observations are used to describe behavior. Correlational studies are further designed to find statistical connections, or correlations, between variables so that some factors can be used to predict others.
A correlation is a statistical measure of the extent to which two variables are associated. A positive correlation exists when two variables increase or decrease together. For example, frustration and aggression are positively correlated, meaning that as frustration rises, so do acts of aggression. More of one means more of the other. A negative correlation exists when increases in one variable are accompanied by decreases in the other, and vice versa. For example, friendships and stress-induced illness are negatively correlated, meaning that the more close friends a person has, the fewer stress-related illnesses the person suffers. More of one means less of the other.
Based on correlational evidence, researchers can use one variable to make predictions about another variable. But researchers must use caution when drawing conclusions from correlations. It is nature-but incorrect-to assume that because one variable predicts another, the first must have caused the second. For example, one might assume that frustration triggers aggression, or that friendships foster health. Regardless of how intuitive or accurate these conclusions may be, correlation does not prove causation. Thus, although it is possible that frustration causes aggression, there are other ways to interpret the correlation. For example, it is possible that aggressive people are more likely to suffer social rejection and become frustrated as a result.
Correlations enable researchers to predict one variable from another. But to determine if one variable actually causes another, psychologists must conduct experiments. In an experiment, the psychologist manipulates one factor in a situation-keeping other aspects of the situation constant-and then observes the effect of the manipulation on behavior. The people whose behavior is being observed are the subjects of the experiment. The factor that an experimenter varies (the proposed cause) is known as the independent variable, and the behavior being measured (the proposed effect) is called the dependent variable. In a test of the hypothesis that frustration triggers aggression, frustration would be the independent variable, and aggression the dependent variable.
There are three requirements for conducting a valid scientific experiment: (1) control over the independent variable, (2) the use of a comparison group, and (3) the random assignment of subjects to conditions. In its most basic form, then, a typical experiment compares a large number of subjects who are randomly assigned to experience one condition with a group of similar subjects who are not. Those who experience the condition compose the experimental group, and those who do not make up the control group. If the two groups differ significantly in their behavior during the experiment, that difference can be attributed to the presence of the condition, or independent variable. For example, to test the hypothesis that frustration triggers aggression, one group of researchers brought subjects into a laboratory, impeded their efforts to complete an important task (other subjects in the experiment were not impeded), and measured their aggressiveness toward another person. These researchers found that subjects who had been frustrated were more aggressive than those who had not been frustrated.
Psychologists use many different methods in their research. Yet no single experiment can fully prove a hypothesis, so the science of psychology builds slowly over time. First, a new discovery must be replicated. Replication refers to the process of conducting a second, nearly identical study to see if the initial findings can be repeated. If so, then researchers try to determine if these findings can be applied, transferred, or generalized to other settings. Generalizability refers to the extent to which a finding obtained less than one set of conditions can also be obtained at another time, in another place, and in other populations.
Because the science of psychology proceeds in small increments, many studies must be conducted before clear patterns emerge. To summarize and interpret an entire body of research, psychologists rely on two methods. One method is a narrative review of the literature, in which a reviewer subjectively evaluates the strengths and weaknesses of the various studies on a topic and argues for certain conclusions. Another method is meta-analysis, a statistical procedure used to combine the results from many different studies. By meta-analyzing a body of research, psychologists can often draw precise conclusions concerning the strength and breadth of support for a hypothesis.
Psychological research involving human subjects raises ethical concerns about the subject”s right to privacy, the possible harm or discomfort caused by experimental procedures, and the use of deception. Over the years, psychologists have established various ethical guidelines. The American Psychological Association recommends that researchers (1) tell prospective subjects what they will experience so they can give informed consent to participate; (2) instruct subjects that they may withdraw from the study at any time; (3) minimize all harm and discomfort; (4) keep the subjects” responses and behavior’s confidential; and (5) debrief subjects who were deceived in some way by fully explaining the research after they have participated. Some psychologists argue that such rules should never be broken. Others say that some degree of flexibility is needed in order to study certain important issues, such as the effects of stress on test performance.
Laboratory experiments that use rats, mice, rabbits, pigeons, monkeys, and other animals are an important part of psychology, just as in medicine. Animal research serves three purposes in psychology: to learn more about certain types of animals, to discover general principles of behavior that pertain to all species, and to study variables that cannot ethically be tested with human beings. But is it ethical to experiment on animals?
Some animal rights activists believe that it is wrong to use animals in experiments, particularly in those that involve surgery, drugs, social isolation, food deprivation, electric shock, and other potentially harmful procedures. These activists see animal experimentation as unnecessary and question whether results from such research can be applied to humans. Many activists also argue that like humans, animals have the capacity to suffer and feel pain. In response to these criticisms, many researchers point out that animal experimentation has helped to improve the quality of human life. They note that animal studies have contributed to the treatment of anxiety, depression, and other mental disorders. Animal studies have also contributed to our understanding of conditions such as Alzheimer's disease, obesity, alcoholism, and the effects of stress on the immune system. Most researchers follow strict ethical guidelines that require them to minimize pain and discomfort to animals and to use the least invasive procedures possible. In addition, federal animal-protection laws in the United States require researchers to provide humane care and housing of animals and to tend to the psychological well-being of primates used in research.
One of the youngest sciences, psychology did not emerge as a formal discipline until the late 19th century. But its roots extend to the ancient past. For centuries, philosophers and religious scholars have wondered about the nature of the mind and the soul. Thus, the history of psychological thought begins in philosophy.
From about 600 to 300 Bc, Greek philosophers inquired about a wide range of psychological topics. They were especially interested in the nature of knowledge and how human beings come to know the world, a field of philosophy known as epistemology. The Greek philosopher Socrates and his followers, Plato and Aristotle, wrote about pleasure and pain, knowledge, beauty, desire, free will, motivation, common sense, rationality, memory, and the subjective nature of perception. They also theorized about whether human traits are innate or the product of experience. In the field of ethics, philosophers of the ancient world probed a variety of psychological questions: Are people inherently good? How can people attain happiness? What motives or drives do people have? Are human beings naturally social?
Second-century physician Galen was one of the most influential figures in ancient medicine, second in importance only to Hippocrates. Using animal dissection and other means, Galen proposed numerous theories about the function of different parts of the human body, most notably the brain, heart, and liver. He also derived an impressive understanding of the differences between veins and arteries. In the selection below, Galen discusses his idea that the optimal state, or “constitution,” of the body should be a perfect balance of various internal and external components.
Early thinkers also considered the causes of mental illness. Many ancient societies thought that mental illness resulted from supernatural causes, such as the anger of gods or possession by evil spirits. Both Socrates and Plato focused on psychological forces as the cause of mental disturbance. For example, Plato thought madness results when a person's irrational, animal-like psyche (mind or soul) overwhelms the intellectual, rational psyche. The Greek physician Hippocrates viewed mental disorders as stemming from natural causes, and he developed the first classification system for mental disorders. Galen, a Greek physician who lived in the 2nd century ad, echoed this belief in a physiological basis for mental disorders. He thought they resulted from an imbalance of the four bodily humors: black bile, yellow bile, blood, and phlegm. For example, Galen thought that melancholia (depression) resulted from a person having too much black bile.
More recently, many other men and women contributed to the birth of modern psychology. In the 1600s French mathematician and philosopher René Descartes theorized that the body and mind are separate entities. He regarded the body as a physical entity and the mind as a spiritual entity, and believed the two interacted only through the pineal gland, a tiny structure at the base of the brain. This position became known as dualism. According to dualism, the behavior of the body is determined by mechanistic laws and can be measured in a scientific manner. But the mind, which transcends the material world, cannot be similarly studied.
English philosopher’s Thomas Hobbes and John Locke disagreed. They argued that all human experiences-including sensations, images, thoughts, and feelings-are physical processes occurring within the brain and nervous system. Therefore, these experiences are valid subjects of study. In this view, which later became known as monism, the mind and body are one and the same. Today, in light of years of research indicating that the physical and mental aspects of the human experience are intertwined, most psychologists reject a rigid dualists position.
Many philosophers of the past also debated the question of whether human knowledge is inborn or the product of experience. Nativists believed that certain elementary truths are innate to the human mind and need not be gained through experience. In contrast, empiricist believed that at birth, a person”s mind is like a tabula rasa, or blank slate, and that all human knowledge ultimately comes from sensory experience. Today, all psychologists agree that both types of factors are important in the acquisition of knowledge.
Modern psychology can also be traced to the study of physiology (a branch of biology that studies living organisms and their parts) and medicine. In the 19th century, physiologists began studying the human brain and nervous system, paying particular attention to the topic of sensation. For example, in the 1850s and 1860s German scientist Hermann von Helmholtz studied sensory receptors in the eye and ear, investigating topics such as the speed of neural impulses, color vision, hearing, and space perception. Another important German scientist, Gustav Fechner, founded psychophysics, the study of the relationship between physical stimuli and our subjective sensations of those stimuli. Building on the work of his compatriot Ernst Weber, Fechner developed a technique for measuring people”s subjective sensations of various physical stimuli. He sought to determine the minimum intensity level of a stimulus that is needed to produce a sensation.
English naturalist Charles Darwin was particularly influential in the development of psychology. In 1859 Darwin published On the Origin of Species, in which he proposed that all living forms were a product of the evolutionary process of natural selection. Darwin had based his theory on plants and nonhuman animals, but he later asserted that people had evolved through similar processes, and that human anatomy and behavior could be analyzed in the same way. Darwin's theory of evolution invited comparisons between humans and other animals, and scientists soon began using animals in psychological research.
French neurologist Jean Martin Charcot shows colleagues a female patient with hysteria at La Salpêtrière, a Paris hospital. Charcot gained renown throughout Europe for his method of treating hysteria and other “nervous disorders” through hypnosis. Charcot”s belief that hysteria had psychological rather than physical origins influenced Austrian neurologist Sigmund Freud, who studied under Charcot.
In medicine, physicians were discovering new links between the brain and language. For example, French surgeon Paul Broca discovered that people who suffer damage to a specific part of the brain’s left hemisphere lose the ability to produce fluent speech. This area of the brain became known as Broca's area. A German neurologist, Carl Wernicke, reported in 1874 that people with damage to a different area of the left hemisphere lose their ability to comprehend speech. This region became known as Wernicke's area.
Other physicians focused on the study of mental disorders. In the late 19th century, French neurologist Jean Charcot discovered that some of the patients he was treating for so-called nervous disorders could be cured through hypnosis, a psychological-not medical-form of intervention. Charcot”s work had a profound impact on Sigmund Freud, an Austrian neurologist whose theories would later revolutionize psychology.
Austrian physician Franz Fredrich Anton Mesmer pioneered the induction of trance-like states to cure medical ailments. Mesmer”s work sparked interest among some of his scientific colleagues but was later dismissed as charlatanism. Today, however, Mesmer is considered a pioneer in hypnosis, which is widely believed to be helpful in managing certain medical conditions.
Psychology was predated and somewhat influenced by various pseudoscientific schools of thought-that is, theories that had no scientific foundation. In the late 18th and early 19th centuries, Viennese physician Franz Joseph Gall developed phrenology, the theory that psychological traits and abilities reside in certain parts of the brain and can be measured by the bumps and indentations in the skull. Although phrenology found popular acceptance among the lay public in western Europe and the United States, most scientists ridiculed Gall's ideas. However, research later confirmed the more general point that certain mental activities can be traced to specific parts of the brain.
Physicians in the 18th and 19th centuries used crude devices to treat mental illness, none of which offered any real relief. The circulating swing, top left, was used to spin depressed patients at high speed. American physician Benjamin Rush devised the tranquilizing chair, top right, to calm people with mania. The crib, bottom, was widely used to restrain violent patients.
Another Viennese physician of the 18th century, Franz Anton Mesmer, believed that illness was caused by an imbalance of magnetic fluids in the body. He believed he could restore the balance by passing his hands across the patient”s body and waving a magnetic wand over the infected area. Mesmer claimed that his patients would fall into a trance and awaken from it feeling better. The medical community, however, soundly rejected the claim. Today, Mesmer”s technique, known as mesmerism, is regarded as an early forerunner of modern hypnosis.
Modern psychology is deeply rooted in the older disciplines of philosophy and physiology. But the official birth of psychology is often traced to 1879, at the University of Leipzig, in Leipzig, Germany. There, physiologist Wilhelm Wundt established the first laboratory dedicated to the scientific study of the mind. Wundt”s laboratory soon attracted leading scientists and students from Europe and the United States. Among these were James McKeen Cattell, one of the first psychologists to study individual differences through the administration of “mental tests,” Emil Kraepelin, a German psychiatrist who postulated a physical cause for mental illnesses and in 1883 published the first classification system for mental disorders; and Hugo Münsterberg, the first to apply psychology to industry and the law. Wundt was extraordinarily productive over the course of his career. He supervised a total of 186 doctoral dissertations, taught thousands of students, founded the first scholarly psychological journal, and published innumerable scientific studies. His goal, which he stated in the preface of a book he wrote, was “to mark out a new domain of science.”
Compared to the philosophers who preceded him, Wundt”s approach to the study of mind was based on systematic and rigorous observation. His primary method of research was introspection. This technique involved training people to concentrate and report on their conscious experiences as they reacted to visual displays and other stimuli. In his laboratory, Wundt systematically studied topics such as attention span, reaction time, vision, emotion, and time perception. By recruiting people to serve as subjects, varying the conditions of their experience, and then rigorously repeating all observations, Wundt laid the foundation for the modern psychology experiment.
In the United States, Harvard University professor William James observed the emergence of psychology with great interest. Although trained in physiology and medicine, James was fascinated by psychology and philosophy. In 1875 he offered his first course in psychology. In 1890 James published a two-volume book entitled Principles of Psychology. It immediately became the leading psychology text in the United States, and it brought James a worldwide reputation as a man of great ideas and inspiration. In 28 chapters, James wrote about the stream of consciousness, the formation of habits, individuality, the link between mind and body, emotions, the self, and other topics that inspired generations of psychologists. Today, historians consider James the founder of American psychology.
James's students also made lasting contributions to the field. In 1883 G. Stanley Hall (who also studied with Wundt) established the first true American psychology laboratory in the United States at Johns Hopkins University, and in 1892 he founded and became the first president of the American Psychological Association. Mary Whiton Calkins created an important technique for studying memory and conducted one of the first studies of dreams. In 1905 she was elected the first female president of the American Psychological Association. Edward Lee Thorndike conducted some of the first experiments on animal learning and wrote a pioneering textbook on educational psychology.
During the first decades of psychology, two main schools of thought dominated the field: structuralism and functionalism. Structuralism was a system of psychology developed by Edward Bradford Titchener, an American psychologist who studied under Wilhelm Wundt. Structuralists believed that the task of psychology is to identify the basic elements of consciousness in much the same way that physicists break down the basic particles of matter. For example, Titchener identified four elements in the sensation of taste: sweet, sour, salty, and bitter. The main method of investigation in structuralism was introspection. The influence of structuralism in psychology faded after Titchener's death in 1927.
In contradiction to the Structuralists movement, William James promoted a school of thought known as functionalism, the belief that the real task of psychology is to investigate the function, or purpose, of consciousness rather than its structure. James was highly influenced by Darwin”s evolutionary theory that all characteristics of a species must serve some adaptive purpose. Functionalism enjoyed widespread appeal in the United States. Its three main leaders were James Rowland Angell, a student of James; John Dewey, who was also one of the foremost American philosophers and educators; and Harvey A. Carr, a psychologist at the University of Chicago.
In their efforts to understand human behavioral processes, the functional psychologists developed the technique of longitudinal research, which consists of interviewing, testing, and observing one person over a long period of time. Such a system permits the psychologist to observe and record the person”s development and how he or she reacts to different circumstances.
In the late 19th century Viennese neurologist Sigmund Freud developed a theory of personality and a system of psychotherapy known as psychoanalysis. According to this theory, people are strongly influenced by unconscious forces, including innate sexual and aggressive drives. In this 1938 British Broadcasting Corporation interview, Freud recounts the early resistance to his ideas and later acceptance of his work. Freud's speech is slurred because he was suffering from cancer of the jaw. He died the following year.
Alongside Wundt and James, a third prominent leader of the new psychology was Sigmund Freud, a Viennese neurologist of the late 19th and early 20th century. Through his clinical practice, Freud developed a very different approach to psychology. After graduating from medical school, Freud treated patients who appeared to suffer from certain ailments but had nothing physically wrong with them. These patients were not consciously faking their symptoms, and often the symptoms would disappear through hypnosis, or even just by talking. On the basis of these observations, Freud formulated a theory of personality and a form of psychotherapy known as psychoanalysis. It became one of the most influential schools of Western thought of the 20th century.
Freud introduced his new theory in The Interpretation of Dreams (1889), the first of 24 books he would write. The theory is summarized in Freud's last book, An Outline of Psychoanalysis, published in 1940, after his death. In contrast to Wundt and James, for whom psychology was the study of conscious experience, Freud believed that people are motivated largely by unconscious forces, including strong sexual and aggressive drives. He likened the human mind to an iceberg: The small tip that floats on the water is the conscious part, and the vast region beneath the surface comprises the unconscious. Freud believed that although unconscious motives can be temporarily suppressed, they must find a suitable outlet in order for a person to maintain a healthy personality.
To probe the unconscious mind, Freud developed the psychotherapy technique of free association. In free association, the patient reclines and talks about thoughts, wishes, memories, and whatever else comes to mind. The analyst tries to interpret these verbalizations to determine their psychological significance. In particular, Freud encouraged patients to free associate about their dreams, which he believed were the “royal road to the unconscious.” According to Freud, dreams are disguised expressions of deep, hidden impulses. Thus, as patients recount the conscious manifest content of dreams, the psychoanalyst tries to unmask the underlying latent content-what the dreams really mean.
From the start of psychoanalysis, Freud attracted followers, many of whom later proposed competing theories. As a group, these neo-Freudians shared the assumption that the unconscious plays an important role in a person”s thoughts and behaviors. Most parted company with Freud, however, over his emphasis on sex as a driving force. For example, Swiss psychiatrist Carl Jung theorized that all humans inherit a collective unconscious that contains universal symbols and memories from their ancestral past. Austrian physician Alfred Adler theorized that people are primarily motivated to overcome inherent feelings of inferiority. He wrote about the effects of birth order in the family and coined the term sibling rivalry. Karen Horney, a German-born American psychiatrist, argued that humans have a basic need for love and security, and become anxious when they feel isolated and alone.
Motivated by a desire to uncover unconscious aspects of the psyche, psychoanalytic researchers devised what are known as projective tests. A projective test asks people to respond to an ambiguous stimulus such as a word, an incomplete sentence, an inkblot, or an ambiguous picture. These tests are based on the assumption that if a stimulus is vague enough to accommodate different interpretations, then people will use it to project their unconscious needs, wishes, fears, and conflicts. The most popular of these tests are the Rorschach Inkblot Test, which consists of ten inkblots, and the Thematic Apperception Test, which consists of drawings of people in ambiguous situations.
Psychoanalysis has been criticized on various grounds and is not as popular as in the past. However, Freud's overall influence on the field has been deep and lasting, particularly his ideas about the unconscious. Today, most psychologists agree that people can be profoundly influenced by unconscious forces, and that people often have a limited awareness of why they think, feel, and behave as they do.
In 1885 German philosopher Hermann Ebbinghaus conducted one of the first studies on memory, using himself as a subject. He memorized lists of nonsense syllables and then tested his memory of the syllables at intervals ranging from 20 minutes to 31 days. As shown in this curve, he found that he remembered less than 40 percent of the items after nine hours, but that the rate of forgetting leveled off over time.
In addition to Wundt, James, and Freud, many other’s scholars helped to define the science of psychology. In 1885 German philosopher Hermann Ebbinghaus conducted a series of classic experiments on memory, using nonsense syllables to establish principles of retention and forgetting. In 1896 American psychologist Lightner Witmer opened the first psychological clinic, which initially treated children with learning disorders. He later founded the first journal and training program in a new helping profession that he named clinical psychology. In 1905 French psychologist Alfred Binet devised the first major intelligence test in order to assess the academic potential of schoolchildren in Paris. The test was later translated and revised by Stanford University psychologist Lewis Terman and is now known as the Stanford-Binet intelligence test. In 1908 American psychologist Margaret Floy Washburn (who later became the second female president of the American Psychological Association) wrote an influential book called The Animal Mind, in which she synthesized animal research to that time.
In 1912 German psychologist Max Wertheimer discovered that when two stationary lights flash in succession, people see the display as a single light moving back and forth. This illusion inspired the Gestalt psychology movement, which was based on the notion that people tend to perceive a well-organized whole or pattern that is different from the sum of isolated sensations. Other leaders of Gestalt psychology included Wertheimer”s close associates Wolfgang Köhler and Kurt Koffka. Later, German American psychologist Kurt Lewin extended Gestalt psychology to studies of motivation, personality, social psychology, and conflict resolution. German American psychologist Fritz Heider then extended this approach to the study of how people perceive themselves and others.
In the late 19th century, American psychologist Edward L. Thorndike conducted some of the first experiments on animal learning. Thorndike formulated the law of effect, which states that behaviors that are followed by pleasant consequences will be more likely to be repeated in the future.
William James had defined psychology as “the science of mental life.” But in the early 1900s, growing numbers of psychologists voiced criticism of the approach used by scholars to explore conscious and unconscious mental processes. These critics doubted the reliability and usefulness of the method of introspection, in which subjects are asked to describe their own mental processes during various tasks. They were also critical of Freud's emphasis on unconscious motives. In search of more-scientific methods, psychologists gradually turned away from research on invisible mental processes and began to study only behavior that could be observed directly. This approach, known as behaviorism, ultimately revolutionized psychology and remained the dominant school of thought for nearly 50 years.
Russian physiologist Ivan Pavlov discovered a major type of learning, classical conditioning, by accident while conducting experiments on digestion in the early 1900s. He devoted the rest of his life to discovering the underlying principles of classical conditioning.
Among the first to lay the foundation for the new behaviorism was American psychologist Edward Lee Thorndike. In 1898 Thorndike conducted a series of experiments on animal learning. In one study, he put cats into a cage, put food just outside the cage, and timed how long it took the cats to learn how to open an escape door that led to the food. Placing the animals in the same cage again and again, Thorndike found that the cats would repeat behaviors that worked and would escape more and more quickly with successive trials. Thorndike thereafter proposed the law of effect, which states that behaviors that are followed by a positive outcome are repeated, while those followed by a negative outcome or none at all are extinguished.
In 1906 Russian physiologist Ivan Pavlov-who had won a Nobel Prize two years earlier for his studies of digestion-stumbled onto one of the most important principles of learning and behavior. Pavlov was investigating the digestive process in dogs by putting food in their mouths and measuring the flow of saliva. He found that after repeated testing, the dogs would salivate in anticipation of the food, even before he put it in their mouth. He soon discovered that if he rang a bell just before the food was presented each time, the dogs would eventually salivate at the mere sound of the bell. Pavlov had discovered a basic form of learning called classical conditioning (also referred to as Pavlovian conditioning) in which an organism comes to associate one stimulus with another. Later research showed that this basic process can account for how people form certain preferences and fears.
American psychologist John B. Watson believed psychologists should study observable behavior instead of speculating about a person”s inner thoughts and feelings. Watson's approach, which he termed behaviorism, dominated psychology for the first half of the 20th century.
Although Thorndike and Pavlov set the stage for behaviorism, it was not until 1913 that a psychologist set forward a clear vision for behaviorist psychology. In that year John Watson, a well-known animal psychologist at Johns Hopkins University, published a landmark paper entitled “Psychology as the Behaviorist Views It.” Watson”s goal was nothing less than a complete redefinition of psychology. “Psychology as the behaviorist views it.” Watson wrote, “is a purely objective experimental branch of natural science. Its theoretical goal is the prediction and control of behavior.” Watson narrowly defined psychology as the scientific study of behavior. He urged his colleagues to abandon both introspection and speculative theories about the unconscious. Instead he stressed the importance of observing and quantifying behavior. In light of Darwin”s theory of evolution, he also advocated the use of animals in psychological research, convinced that the principles of behavior would generalize across all species.
American psychologist B. F. Skinner became famous for his pioneering research on learning and behavior. During his 60-year career, Skinner discovered important principles of operant conditioning, a type of learning that involves reinforcement and punishment. A strict behaviorist, Skinner believed that operant conditioning could explain even the most complex of human behaviors.
Many American psychologists were quick to adopt behaviorism, and animal laboratories were set up all over the country. Aiming to predict and control behavior, the "behaviorists” strategy was to vary a stimulus in the environment and observe an organism's response. They saw no need to speculate about mental processes inside the head. For example, Watson argued that thinking was simply talking to oneself silently. He believed that thinking could be studied by recording the movement of certain muscles in the throat.
American psychologist B. F. Skinner designed an apparatus, now called a Skinner box, that allowed him to formulate important principles of animal learning. An animal placed inside the box is rewarded with a small bit of food each time it makes the desired response, such as pressing a lever or pecking a key. A device outside the box records the animal”s responses.
The most forceful leader of behaviorism was B. F. Skinner, an American psychologist who began studying animal learning in the 1930s. Skinner coined the term reinforcement and invented a new research apparatus called the Skinner box for use in testing animals. Based on his experiments with rats and pigeons, Skinner identified a number of basic principles of learning. He claimed that these principles explained not only the behavior of laboratory animals, but also accounted for how human beings learn new behaviors or change existing behaviors. He concluded that nearly all behavior is shaped by complex patterns of reinforcement in a person”s environment, a process that he called operant conditioning (also referred to as instrumental conditioning). Skinner”s views on the causes of human behavior made him one of the most famous and controversial psychologists of the 20th century.
Operant conditioning, pioneered by American psychologist B. F. Skinner, is the process of shaping behavior by means of reinforcement and punishment. This illustration shows how a mouse can learn to maneuver through a maze. The mouse is rewarded with food when it reaches the first turn in the maze (A). Once the first behavior becomes ingrained, the mouse is not rewarded until it makes the second turn (B). After many times through the maze, the mouse must reach the end of the maze to receive its reward ©.
Skinner and others applied his findings to modify behavior in the workplace, the classroom, the clinic, and other settings. In World War II (1939-1945), for example, he worked for the U.S. government on a top-secret project in which he trained pigeons to guide an armed glider plane toward enemy ships. He also invented the first teaching machine, which allowed students to learn at their own pace by solving a series of problems and receiving immediate feedback. In his popular book Walden Two (1948), Skinner presented his vision of a behaviorist utopia, in which socially adaptive behaviors are maintained by rewards, or positive reinforcements. Throughout his career, Skinner held firm to his belief that psychologists should focus on the prediction and control of behavior.
Faced with a choice between psychoanalysis and behaviorism, many psychologists in the 1950s and 1960s sensed a void in psychology”s conception of human nature. Freud had drawn attention to the darker forces of the unconscious, and Skinner was interested only in the effects of reinforcement on observable behavior. Humanistic psychology was born out of a desire to understand the conscious mind, free will, human dignity, and the capacity for self-reflection and growth. An alternative to psychoanalysis and behaviorism, humanistic psychology became known as “the third force.”
The humanistic movement was led by American psychologists Carl Rogers and Abraham Maslow. According to Rogers, all humans are born with a drive to achieve their full capacity and to behave in ways that are consistent with their true selves. Rogers, a psychotherapist, developed person-centered therapy, a nonjudgmental, nondirective approach that helped clients clarify their sense of whom they are in an effort to facilitate their own healing process. At about the same time, Maslow theorized that all people are motivated to fulfill a hierarchy of needs. At the bottom of the hierarchy are basic physiological needs, such as hunger, thirst, and sleep. Further up the hierarchy are needs for safety and security, needs for belonging and love, and esteem-related needs for status and achievement. Once these needs are met, Maslow believed, people strive for self-actualization, the ultimate state of personal fulfillment. As Maslow put it: A musician must make music, an artist must paint, a poet must write, if he is ultimately to be at peace with himself. "What a man can be, he must be.
Swiss psychologist Jean Piaget based his early theories of intellectual development on his questioning and observation of his own children. From these and later studies, Piaget concluded that all children pass through a predictable series of cognitive stages.
From the 1920s through the 1960s, behaviorism dominated psychology in the United States. Eventually, however, psychologists began to move away from strict behaviorism. Many became increasingly interested in cognition, a term used to describe all the mental processes involved in acquiring, storing, and using knowledge. Such processes include perception, memory, thinking, problem solving, imagining, and language. This shift in emphasis toward cognition had such a profound influence on psychology that it has often been called the cognitive revolution. The psychological study of cognition became known as cognitive psychology.
One reason for psychologists” renewed interest in mental processes was the invention of the computer, which provided an intriguing metaphor for the human mind. The hardware of the computer was likened to the brain, and computer programs provided a step-by-step model of how information from the environment is input, stored, and retrieved to produce a response. Based on the computer metaphor, psychologists began to formulate information-processing models of human thought and behavior.
In the 1950s American linguist Noam Chomsky proposed that the human brain is especially constructed to detect and reproduce language and that the ability to form and understand language is innate to all human beings. According to Chomsky, young children learn and apply grammatical rules and vocabulary as they are exposed to them and do not require initial formal teaching.
The pioneering work of Swiss psychologist Jean Piaget also inspired psychologists to study cognition. During the 1920s, while administering intelligence tests in schools, Piaget became interested in how children think. He designed various tasks and interview questions to reveal how children of different ages reason about time, nature, numbers, causality, morality, and other concepts. Based on his many studies, Piaget theorized that from infancy to adolescence, children advance through a predictable series of cognitive stages.
The cognitive revolution also gained momentum from developments in the study of language. Behaviorist B. F. Skinner had claimed that language is acquired according to the laws of operant conditioning, in much the same way that rats learn to press a bar for food pellets. In 1959, however, American linguist Noam Chomsky charged that Skinner's account of language development was wrong. Chomsky noted that children all over the world start to speak at roughly the same age and proceed through roughly the same stages without being explicitly taught or rewarded for the effort. According to Chomsky, the human capacity for learning language is innate. He theorized that the human brain is “hardwired” for language as a product of evolution. By pointing to the primary importance of biological dispositions in the development of language, Chomsky”s theory dealt a serious blow to the behaviorist assumption that all human behaviors are formed and maintained by reinforcement.
Before psychology became established in science, it was popularly associated with extrasensory perception (ESP) and other paranormal phenomena (phenomena beyond the laws of science). Today, these topics lie outside the traditional scope of scientific psychology and fall within the domain of parapsychology. Psychologists note that thousands of studies have failed to demonstrate the existence of paranormal phenomena.
Grounded in the conviction that mind and behavior must be studied using statistical and scientific methods, psychology has become a highly respected and socially useful discipline. Psychologists now study important and sensitive topics such as the similarities and differences between men and women, racial and ethnic diversity, sexual orientation, marriage and divorce, abortion, adoption, intelligence testing, sleep and sleep disorders, obesity and dieting, and the effects of psychoactive drugs such as methylphenidate (Ritalin) and fluoxetine (Prozac).
In the last few decades, researchers have made significant breakthroughs in understanding the brain, mental processes, and behavior. This section of the article provides examples of contemporary research in psychology: the plasticity of the brain and nervous system, the nature of consciousness, memory distortions, competence and rationality, genetic influences on behavior, infancy, the nature of intelligence, human motivation, prejudice and discrimination, the benefits of psychotherapy, and the psychological influences on the immune system.
Psychologists once believed that the neural circuits of the adult brain and nervous system were fully developed and no longer subject to change. Then in the 1980s and 1990s a series of provocative experiments showed that the adult brain has flexibility, or plasticity-a capacity to change as a result of usage and experience.
These experiments showed that adult rats flooded with visual stimulation formed new neural connections in the brain's visual cortex, where visual signals are interpreted. Likewise, those trained to run an obstacle course formed new connections in the cerebellum, where balance and motor skills are coordinated. Similar results with birds, mice, and monkeys have confirmed the point: Experience can stimulate the growth of new connections and mold the brain”s neural architecture.
Once the brain reaches maturity, the number of neurons does not increase, and any neurons that are damaged are permanently disabled. But the plasticity of the brain can greatly benefit people with damage to the brain and nervous system. Organisms can compensate for loss by strengthening old neural connections and sprouting new ones. That is why people who suffer strokes are often able to recover their lost speech and motor abilities.
In 1860 German physicist Gustav Fechner theorized that if the human brain were divided into right and left halves, each side would have its own stream of consciousness. Modern medicine has actually allowed scientists to investigate this hypothesis. People who suffer from life-threatening epileptic seizures sometimes undergo a radical surgery that severs the corpus callosum, a bridge of nerve tissue that connects the right and left hemispheres of the brain. After the surgery, the two hemispheres can no longer communicate with each other.
Scientists have long considered the nature of consciousness without producing a fully satisfactory definition. In the early 20th century American philosopher and psychologist William James suggested that consciousness is a mental process involving both attention to external stimuli and short-term memory. Later scientific explorations of consciousness mostly expanded upon James”s work. In this article from a 1997 special issue of Scientific American, Nobel laureate Francis Crick, who helped determine the structure of DNA, and fellow biophysicist Christof Koch explain how experiments on vision might deepen our understanding of consciousness.
Beginning in the 1960s American neurologist Roger Sperry and others tested such split-brain patients in carefully designed experiments. The researchers found that the hemispheres of these patients seemed to function independently, almost as if the subjects had two brains. In addition, they discovered that the left hemisphere was capable of speech and language, but not the right hemisphere. For example, when split-brain patients saw the image of an object flashed in their left visual field (thus sending the visual information to the right hemisphere), they were incapable of naming or describing the object. Yet they could easily point to the correct object with their left hand (which is controlled by the right hemisphere). As Sperry”s colleague Michael Gazzaniga stated, “Each half brain seemed to work and function outside of the conscious realm of the other.”
Other psychologists interested in consciousness have examined how people are influenced without their awareness. For example, research has demonstrated that under certain conditions in the laboratory, people can be fleetingly affected by subliminal stimuli, sensory information presented so rapidly or faintly that it falls below the threshold of awareness. (Note, however, that scientists have discredited claims that people can be importantly influenced by subliminal messages in advertising, rock music, or other media.) Other evidence for influence without awareness comes from studies of people with a type of amnesia that prevents them from forming new memories. In experiments, these subjects are unable to recognize words they previously viewed in a list, but they are more likely to use those words later in an unrelated task. In fact, memory without awareness is normal, as when people come up with an idea they think is original, only later to realize that they had inadvertently borrowed it from another source.
Cognitive psychologists have often likened human memory to a computer that encodes, stores, and retrieves information. It is now clear, however, that remembering is an active process and that people construct and alter memories according to their beliefs, wishes, needs, and information received from outside sources.
Without realizing it, people sometimes create memories that are false. In one study, for example, subjects watched a slide show depicting a car accident. They saw either a “STOP” sign or a “YIELD” sign in the slides, but afterward they were asked a question about the accident that implied the presence of the other sign. Influenced by this suggestion, many subjects recalled the wrong traffic sign. In another study, people who heard a list of sleep-related words (bed, yawn) or music-related words (jazz, instrument) were often convinced moments later that they had also heard the words sleep or music-words that fit the category but were not on the list. In a third study, researchers asked college students to recall their high-school grades. Then the researchers checked those memories against the students” actual transcripts. The students recalled most grades correctly, but most of the errors inflated their grades, particularly when the actual grades were low. When scientists distinguish between human beings and other animals, they point to our larger cerebral cortex (the outer part of the brain) and to our superior intellect-as seen in the abilities to acquire and store large amounts of information, solve problems, and communicate through the use of language.
In recent years, however, those studying human cognition have found that people are often less than rational and accurate in their performance. Some researchers have found that people are prone to forgetting, and worse, that memories of past events are often highly distorted. Others have observed that people often violate the rules of logic and probability when reasoning about real events, as when gamblers overestimate the odds of winning in games of chance. One reason for these mistakes is that we commonly rely on cognitive heuristics, mental shortcuts that allow us to make judgments that are quick but often in error. To understand how heuristics can lead to mistaken assumptions, imagine offering people a lottery ticket containing six numbers out of a pool of the numbers 1 through 40. If given a choice between the tickets 6-39-2-10-24-30 or 1-2-3-4-5-6, most people select the first ticket, because it has the appearance of randomness. Yet out of the 3,838,380 possible winning combinations, both sequences are equally likely.
One of the oldest debates in psychology, and in philosophy, concerns whether individual human traits and abilities are predetermined from birth or due to one's upbringing and experiences. This debate is often termed the nature-nurture debate. A strict genetic (nature) position states that people are predisposed to become sociable, smart, cheerful, or depressed according to their genetic blueprint. In contrast, a strict environmental (nurture) position says that people are shaped by parents, peers, cultural institutions, and life experiences.
Research shows that the more genetically related a person is to someone with schizophrenia, the greater the risk that person has of developing the illness. For example, children of one parent with schizophrenia have a 13 percent chance of developing the illness, whereas children of two parents with schizophrenia have a 46 percent chance of developing the disorder.
Researchers can estimate the role of genetic factors in two ways: (1) twin studies and (2) adoption studies. Twin studies compare identical twins with fraternal twins of the same sex. If identical twins (who share all the same genes) are more similar to each other on a given trait than are same-sex fraternal twins (who share only about half of the same genes), then genetic factors are assumed to influence the trait. Other studies compare identical twins who are raised together with identical twins who are separated at birth and raised in different families. If the twins raised together are more similar to each other than the twins raised apart, childhood experiences are presumed to influence the trait. Sometimes researchers conduct adoption studies, in which they compare adopted children to their biological and adoptive parents. If these children display traits that resemble those of their biological relatives more than their adoptive relatives, genetic factors are assumed to play a role in the trait.
In recent years, several twin and adoption studies have shown that genetic factors play a role in the development of intellectual abilities, temperament and personality, vocational interests, and various psychological disorders. Interestingly, however, this same research indicates that at least 50 percent of the variation in these characteristics within the population is attributable to factors in the environment. Today, most researchers agree that psychological characteristics spring from a combination of the forces of nature and nurture.
Helpless to survive on their own, newborn babies nevertheless possess a remarkable range of skills that aid in their survival. Newborns can see, hear, taste, smell, and feel pain; vision is the least developed sense at birth but improves rapidly in the first months. Crying communicates their need for food, comfort, or stimulation. Newborns also have reflexes for sucking, swallowing, grasping, and turning their head in search of their mother”s nipple.
In 1890 William James described the newborn”s experience as “one great blooming, buzzing confusion.” However, with the aid of sophisticated research methods, psychologists have discovered that infants are smarter than was previously known.
A period of dramatic growth, infancy lasts from birth to around 18 months of age. Researchers have found that infants are born with certain abilities designed to aid their survival. For example, newborns show a distinct preference for human faces over other visual stimuli.
To learn about the perceptual world of infants, researchers measure infants” head movements, eye movements, facial expressions, brain waves, heart rate, and respiration. Using these indicators, psychologists have found that shortly after birth, infants show a distinct preference for the human face over other visual stimuli. Also suggesting that newborns are tuned into the face as a social object is the fact that within 72 hours of birth, they can mimic adults who purse the lips or stick out the tongue-a rudimentary form of imitation. Newborns can distinguish between their mother”s voice and that of another woman. And at two weeks old, nursing infants are more attracted to the body odor of their mother and other breast-feeding females than to that of other women. Taken together, these findings show that infants are equipped at birth with certain senses and reflexes designed to aid their survival.
In 1905 French psychologist Alfred Binet and colleague Théodore Simon devised one of the first tests of general intelligence. The test sought to identify French children likely to have difficulty in school so that they could receive special education. An American version of Binet”s test, the Stanford-Binet Intelligence Scale, is still used today.
In 1905 French psychologist Alfred Binet devised the first major intelligence test for the purpose of identifying slow learners in school. In doing so, Binet assumed that intelligence could be measured as a general intellectual capacity and summarized in a numerical score, or intelligence quotient (IQ). Consistently, testing has revealed that although each of us is more skilled in some areas than in others, a general intelligence underlies our more specific abilities.
Intelligence tests often play a decisive role in determining whether a person is admitted to college, graduate school, or professional school. Thousands of people take intelligence tests every year, but many psychologists and education experts question whether these tests are an accurate way of measuring who will succeed or fail in school and later in life. In this 1998 Scientific American article, psychology and education professor Robert J. Sternberg of Yale University in New Haven, Connecticut, presents evidence against conventional intelligence tests and proposes several ways to improve testing.
Today, many psychologists believe that there is more than one type of intelligence. American psychologist Howard Gardner proposed the existence of multiple intelligence, each linked to a separate system within the brain. He theorized that there are seven types of intelligence: linguistic, logical-mathematical, spatial, musical, bodily-kinesthetic, interpersonal, and intrapersonal. American psychologist Robert Sternberg suggested a different model of intelligence, consisting of three components: analytic (“school smarts,” as measured in academic tests), creative (a capacity for insight), and practical (“street smarts,” or the ability to size up and adapt to situations). Psychologists from all branches of the discipline study the topic of motivation, an inner state that moves an organism toward the fulfillment of some goal. Over the years, different theories of motivation have been proposed. Some theories state that people are motivated by the need to satisfy physiological needs, whereas others state that people seek to maintain an optimum level of bodily arousal (not too little and not too much). Still other theories focus on the ways in which people respond to external incentives such as money, grades in school, and recognition. Motivation researchers study a wide range of topics, including hunger and obesity, sexual desire, the effects of reward and punishment, and the needs for power, achievement, social acceptance, love, and self-esteem.
In 1954 American psychologist Abraham Maslow proposed that all people are motivated to fulfill a hierarchical pyramid of needs. At the bottom of Maslow”s pyramid are needs essential to survival, such as the needs for food, water, and sleep. The need for safety follows these physiological needs. According to Maslow, higher-level needs become important to us only after our more basic needs are satisfied. These higher needs include the need for love and belongingness, the need for esteem, and the need for self-actualization (in Maslow”s theory, a state in which people realize their greatest potential).
The view that the role of sentences in inference gives a more important key to their meaning than their “external” relations to things in the world. The meaning of a sentence becomes its place in a network of inferences that it legitimates. Also, known as its functional role semantics, procedural semantic or conceptual role semantics. As these view bear some relation to the coherence theory of truth, and suffers from the same suspicion that divorces meaning from any clear association with things in the world.
Paradoxes rest upon the assumption that analysis is a relation with concept, then are involving entities of other sorts, such as linguistic expressions, and that in true analysis, analysand and analysandum are one and the same concept. However, these assumptions are explicit in the British philosopher George Edward Moore, but some of Moore”s remarks hint at a solution that a statement of an analysis is a statement partially taken about the concept involved and partly about the verbal expression used to express it. Moore is to suggest that he thinks of a solution of this sort is bound to be right, however, facts to suggest one because he cannot reveal of any way in which the analysis can be as part of the expression.
Elsewhere, the possibility clearly does set of apparent incontrovertible premises giving unacceptable or contradictory conclusions. To solve a paradox will involve showing that either these hidden flaws in the premises, or what the reasoning is erroneous, or that the apparently unacceptable conclusion can, in fact, be tolerable. Paradoxes are therefore important in philosophy, for until one is solved it shows that there is something about our reasoning and our concepts that we do not understand. Famous families of paradoxes include the semantic paradoxes and Zeno's paradoxes. At the beginning of the 20th century, Russell's paradox and other set-theoretic paradoxes of set theory, while the Sorites paradox has led to the investigation of the semantics of vagueness, and fuzzy logic. Paradoxes are under their other titles. Much as there is as much as a puzzle arising when someone says “p but I do not believe that p.” What is said is not contradictory, since (for many instances of p) both parts of it could br. true. But the person nevertheless violates one presupposition of normal practice, namely that you assert something only if you believe it: By adding that you do not believe what you just said you undo the natural significance of the original act saying it.
Furthermore, the moral philosopher and epistemologist Bernard Bolzano (1781-1848), whose logical work was based on a strong sense of there being an ontological underpinning of science and epistemology, lying in a theory of the objective entailments masking up the structure of scientific theories. His ability to challenge wisdom and come up with startling new ideas, as a Christian philosopher whether than from any position of mathematical authority, that for considerations of infinity, Bolzano”s significant work was Paradoxin des Unenndlichen, written in retirement and translated into the English as Paradoxes of the Infinite. Here, Bolzano considered directly the points that had concerned Galileo-the conflicting result that seem to emerge when infinity is studied. Certainly most of the paradoxical statements encountered in the mathematical domain . . . are propositions which either immediately contain the idea of the infinite, or at least in some way or other depends upon that idea for their attempted proof.
Continuing, Bolzano looks at two possible approaches to infinity. One is simply the case of setting up a sequence of numbers, such as the whole numbers, and saying that as it cannot conceivably be said to have a last term, it is inherently infinite-not finite. It is easy enough to show that the whole numbers do not have a point at which they stop, giving a name to that last number whatever it might have been to call it “ultimate.” Then what”s wrong with ultimate + 1? Why is that not a whole number?
The second approach to infinity, which Bolzano ascribes in Paradoses of the Infinite to “some philosophers . . . Taking this approach describe his first conception of infinity as the “bad infinity.” Although the German philosopher Friedrich George Hegel (1770-1831) applies the conceptual form of infinity and points that it is, rather, the basis for a substandard infinity that merely reaches toward the absolute, but never reaches it. In Paradoses of the Infinite, he calls this form of potential infinity as a variable quantity knowing no limit to its growth (a definition adopted, even by many mathematicians) . . . always growing int the infinite and never reaching it. As far as Hegel and his colleagues were concerned, using this uprush, there was no need for a real infinity beyond some unreachable absolute. Instead we deal with a variable quality that is as big as we need it to be, or often in calculus as small as we need it to be, without ever reaching the absolute, ultimate, truly infinite.
Bolzano argues, though, that there is something else, an infinity that does not have this “whatever you need it to be” elasticity. In fact a truly infinite quantity (for example, the length of a straight line unbounded in either direction, meaning: The magnitude of the spatial entity containing all the points determined solely by their abstractly conceivable relation to two fixed points) does not by any means need to be variable, and in an adduced example it is in fact not variable. Conversely, it is quite possible for a quantity merely capable of being taken greater than we have already taken it, and of becoming larger than any pre-assigned (finite) quantity, nevertheless to mean at all times merely finitely, which holds in particular of every numerical quantity 1, 2, 3, 4, 5.
In other words, for Bolzano there could be a true infinity that was not a variable “something” that was only bigger than anything you might specify. Such a true infinity was the result of joining two pints together and extending that line in both directions without stopping. And what is more, he could separate off the demands of calculus, using a finite quality without ever bothering with the slippery potential infinity. Here was both a deeper understanding of the nature of infinity and the basis on which are built in his “safe” infinity free calculus.
This use of the inexhaustible follows on directly from most Bolzano”s criticism of the way that ∞we used as a variable something that would be bigger than anything you could specify, but never quite reached the true, absolute infinity. In Paradoxes of the Infinity Bolzano points out that is possible for a quantity merely capable of becoming larger than any other one pre-assigned (finite) quantity, nevertheless to remain at all times merely finite.
Bolzano intended tis as a criticism of the way infinity was treated, but Professor Jacquette sees it instead of a way of masking use of practical applications like calculus without the need for weasel words about infinity.
By replacing ∞with ¤ we do away with one of the most common requirements for infinity, but is there anything left that map out to the real world? Can we confine infinity to that pure mathematical other world, where anything, however unreal, can be constructed, and forget about it elsewhere? Surprisingly, this seems to have been the view, at least at one point in time, even of the German mathematician and founder of set-theory Georg Cantor (1845-1918), himself, whose comments in 1883, that only the finite numbers are real.
Keeping within the lines of reason, both the Cambridge mathematician and philosopher Frank Plumpton Ramsey (1903-30) and the Italian mathematician G. Peano (1858-1932) have been to distinguish logical paradoxes and that depend upon the notion of reference or truth (semantic notions), such are the postulates justifying mathematical induction. It ensures that a numerical series is closed, in the sense that nothing but zero and its successors can be numbers. In that any series satisfying a set of axioms can be conceived as the sequence of natural numbers. Candidates from set theory include the Zermelo numbers, where the empty set is zero, and the successor of each number is its unit set, and the von Neuman numbers, where each number is the set of all smaller numbers. A similar and equally fundamental complementarity exists in the relation between zero and infinity. Although the fullness of infinity is logically antithetical to the emptiness of zero, infinity can be obtained from zero with a simple mathematical operation. The division of many numbers by zero is infinity, while the multiplication of any number by zero is zero.
With the set theory developed by the German mathematician and logician Georg Cantor. From 1878 to 1807, Cantor created a theory of abstract sets of entities that eventually became a mathematical discipline. A set, as he defined it, is a collection of definite and distinguished objects in thought or perception conceived as a whole.
Cantor attempted to prove that the process of counting and the definition of integers could be placed on a solid mathematical foundation. His method was to repeatedly place the elements in one set into “one-to-one” correspondence with those in another. In the case of integers, Cantor showed that each integer (1, 2, 3, . . . n) could be paired with an even integer (2, 4, 6, . . . n), and, therefore, that the set of all integers was equal to the set of all even numbers.
Amazingly, Cantor discovered that some infinite sets were large than others and that infinite sets formed a hierarchy of greater infinities. After this failed attempt to save the classical view of logical foundations and internal consistency of mathematical systems, it soon became obvious that a major crack had appeared in the seemingly sold foundations of number and mathematics. Meanwhile, an impressive number of mathematicians began to see that everything from functional analysis to the theory of real numbers depended on the problematic character of number itself.
While, in the theory of probability Ramsey was the first to show how a personalised theory could be developed, based on precise behavioural notions of preference and expectation. In the philosophy of language, Ramsey was one of the first thinkers to accept a “redundancy theory of truth,” which hr combined with radical views of the function of many kinds of propositions. Neither generalizations nor causal propositions, nor those treating probability or ethics, describe facts, but each has a different specific function in our intellectual economy.
Ramsey advocates that of a sentence generated by taking all the sentences affirmed in a scientific theory that use some term, e.g., “quark.” Replacing the term by a variable, and existentially quantifying into the result. Instead of saying quarks have such-and-such properties, Ramsey postdated that the sentence as saying that there is something that has those properties. If the process is repeated, the sentence gives the “topic-neutral” structure of the theory, but removes any implications that we know what the term so treated denote. I t leaves open the possibility of identifying the theoretical item with whatever it is that best fits the description provided. Nonetheless, it was pointed out by the Cambridge mathematician Newman that if the process is carried out for all except the logical bones of the theory, then by the Löwenheim-Skolem theorem, the result will be interpretable in any domain of sufficient cardinality, and the content of the theory may reasonably be felt to have been lost.
It seems, that the most taken of paradoxes in the foundations of “set theory” as discovered by Russell in 1901. Some classes have themselves as members: The class of all abstract objects, for example, is an abstract object, whereby, others do not: The class of donkeys is not itself a donkey. Now consider the class of all classes that are not members of themselves, is this class a member of itself, that, if it is, then it is not, and if it is not, then it is.
The paradox is structurally similar to easier examples, such as the paradox of the barber. Such one like a village having a barber in it, who shaves all and only the people who do not have in themselves. Who shaves the barber? If he shaves himself, then he does not, but if he does not shave himself, then he does not. The paradox is actually just a proof that there is no such barber or in other words, that the condition is inconsistent. All the same, it is no too easy to say why there is no such class as the one Russell defines. It seems that there must be some restriction on the kind of definition that are allowed to define classes and the difficulty that of finding a well-motivated principle behind any such restriction.
The French mathematician and philosopher Henri Jules Poincaré (1854-1912) believed those paradoses like those of Russell nd the “barber” were due to such as the im predicative definitions, and therefore proposed banning them. But, it tuns out that classical mathematics required such definitions at too many points for the ban to be easily absolved. Having, in turn, as forwarded by Poincaré and Russell, was that in order to solve the logical and semantic paradoxes it would have to ban any collection (set) containing members that can only be defined by means of the collection taken as a whole. It is, effectively by all occurring principles into which have an adopting vicious regress, as to mark the definition for which involves no such failure. There is frequently room for dispute about whether regresses are benign or vicious, since the issue will hinge on whether it is necessary to reapply the procedure. The cosmological argument is an attempt to find a stopping point for what is otherwise seen as an infinite regress, and, to ban of the predicative definitions.
The investigation of questions that arise from reflection upon sciences and scientific inquiry, are such as called of a philosophy of science. Such questions include, what distinctions in the methods of science? Is there a clear demarcation between scenes and other disciplines, and how do we place such enquires as history, economics or sociology? And scientific theories probable or more in the nature of provisional conjecture? Can the be verified or falsified? What distinguished good from bad explanations? Might there be one unified since, embracing all the special science? For much of the 20th century their questions were pursued in a high abstract and logical framework it being supposed that as general logic of scientific discovery that a general logic of scientific discovery a justification might be found. However, many now take interests in a more historical, contextual and sometimes sociological approach, in which the methods and successes of a science at a particular time are regarded less in terms of universal logical principles and procedure, and more in terms of their availability to methods and paradigms as well as the social context.
In addition, to general questions of methodology, there are specific problems within particular sciences, giving subjects as biology, mathematics and physics.
The intuitive certainty that sparks aflame the dialectic awarenesses for its immediate concerns are either of the truths or by some other in an object of apprehensions, such as a concept. Awareness as such, has to its amounting quality value the place where philosophically understanding of the source of our knowledge are, however, in covering the sensible apprehension of things and pure intuition it is that which stricture sensation into the experience of things accent of its direction that orchestrates the celestial overture into measures in space and time.
The notion that determines how something is seen or evaluated of the status of law and morality especially associated with St Thomas Aquinas and the subsequent scholastic tradition. More widely, any attempt to cement the moral and legal order together with the nature of the cosmos or how the nature of human beings, for which sense it is also found in some Protestant writers, and arguably derivative from a Platonic view of ethics, and is implicit in ancient Stoicism. Law stands above and apart from the activities of human lawmaker, it constitutes an objective set of principles that can be seen true by “natural light” or reason, and (in religion versions of the theory) that express God”s will for creation. Non-religious versions of the theory substitute objective conditions for human flourishing as the source of constraints upon permissible actions and social arrangements. Within the natural law tradition, different views have been held about the relationship between the rule of law about God' s will, for instance the Dutch philosopher Hugo Grothius (1583-1645), similarly takes upon the view that the content of natural law is independent of any will, including that of God, while the German theorist and historian Samuel von Pufendorf (1632-94) takes the opposite view, thereby facing the problem of one horn of the Euthyphro dilemma, that simply states, that its dilemma arises from whatever the source of authority is supposed to be, for in which do we care about the general good because it is good, or do we just call good things that we care about. Wherefore, by facing the problem that may be to assume of a strong form, in which it is claimed that various facts entail values, or a weaker form, from which it confines itself to holding that reason by itself is capable of discerning moral requirements that are supped of binding to all human bings regardless of their desires
Although the morality of people send the ethical amount, from which the same thing, is that there is a usage that restricts morality to systems such as that of the German philosopher and founder of ethical philosophy Immanuel Kant (1724-1804), based on notions such as duty, obligation, and principles of conduct, reserving ethics for more than the Aristotelian approach to practical reasoning based on the notion of a virtue, and generally avoiding the separation of “moral” considerations from other practical considerations. The scholarly issues are complex, with some writers seeing Kant as more Aristotelian and Aristotle as, ore involved in a separate sphere of responsibility and duty, than the simple contrast suggests. Some theorists see the subject in terms of a number of laws (as in the Ten Commandments). The status of these laws may be test they are the edicts of a divine lawmaker, or that they are truths of reason, knowable deductively. Other approaches to ethics (e.g., eudaimonism, situation ethics, virtue ethics) eschew general principles as much as possible, frequently disguising the great complexity of practical reasoning. For Kantian notion of the moral law is a binding requirement of the categorical imperative, and to understand whether they are equivalent at some deep level. Kant's own applications of the notion are not always convincing, as for one cause of confusion in relating Kant's ethics to theories such additional expressivism is that it is easy, but mistaken, to suppose that the categorical nature of the imperative means that it cannot be the expression of sentiment, but must derive from something “unconditional” or “necessary” such as the voice of reason.
For whichever reason, the mortal being makes of its presence to the future of weighing of that which one must do, or that which can be required of one. The term carries implications of that which is owed (due) to other people, or perhaps in onself. Universal duties would be owed to persons (or sentient beings) as such, whereas special duty in virtue of specific relations, such for being the child of someone, or having made someone a promise. Duty or obligation is the primary concept of “deontological” approaches to ethics, but is constructed in other systems out of other notions. In the system of Kant, a perfect duty is one that must be performed whatever the circumstances: Imperfect duties may have to give way to the more stringent ones. In another way, perfect duties are those that are correlative with the right to others, imperfect duties are not. Problems with the concept include the ways in which due needs to be specified (a frequent criticism of Kant is that his notion of duty is too abstract). The concept may also suggest of a regimented view of ethical life in which we are all forced conscripts in a kind of moral army, and may encourage an individualistic and antagonistic view of social relations.
The most generally accepted account of externalism and/or internalism, that this distinction is that a theory of justification is internalist if only if it requiem that all of the factors needed for a belief to be epistemologically justified for a given person be cognitively accessible to that person, internal to his cognitive perceptive, and externalist, if it allows that at least some of the justifying factors need not be thus accessible, so that thy can be external to the believer”s cognitively perceptive, beyond any such given relations. However, epistemologists often use the distinction between internalist and externalist theories of epistemic justification without offering any very explicit explication.
The externalist/internalist distinction has been mainly applied to theories of epistemic justification: It has also been applied in a closely related way to accounts of knowledge and in a rather different way to accounts of belief and thought contents.
The internalist requirement of cognitive accessibility can be interpreted in at least two ways: A strong version of internalism would require that the believer actually be aware of the justifying factor in order to be justified: While a weaker version would require only that he be capable of becoming aware of them by focussing his attentions appropriately, but without the need for any change of position, new information, etc. Though the phrase “cognitively accessible” suggests the weak interpretion, the main intuitive motivation for internalism, viz. the idea that epistemic justification requires that the believer actually have in his cognitive possession a reason for thinking that the belief is true, and would require the strong interpretation.
Perhaps, the clearest example of an internalist position would be a Foundationalist view according to which foundational beliefs pertain to immediately experienced states of mind and other beliefs are justified by standing in cognitively accessible logical or inferential relations to such foundational beliefs. Such a view could count as either a strong or a weak version of internalism, depending on whether actual awareness of the justifying elements or only the capacity to become aware of them is required. Similarly, a coherent view could also be internalist, if both the beliefs or other states with which a justification belief is required to cohere and the coherence relations themselves are reflectively accessible.
It should be carefully noticed that when internalism is construed in this way, it is neither necessary nor sufficient by itself for internalism that the justifying factors literally be internal mental states of the person in question. Not necessary, necessary, because on at least some views, e.g., a direct realist view of perception, something other than a mental state of the believer can be cognitively accessible: Not sufficient, because there are views according to which at least some mental states need not be actual (strong version) or even possible (weak version) objects of cognitive awareness. Also, on this way of drawing the distinction, a hybrid view, according to which some of the factors required for justification must be cognitively accessible while others need not and in general will not be, would count as an externalist view. Obviously too, a view that was externalist in relation to a strong version of internalism (by not requiring that the believer actually be aware of all justifying factors) could still be internalist in relation to a weak version (by requiring that he at least be capable of becoming aware of them).
The most prominent recent externalist views have been versions of reliabilism, whose requirements for justification is roughly that the belief be produced in a way or via a process that makes of objectively likely that the belief is true. What makes such a view externalist is the absence of any requirement that the person for whom the belief is justified have any sort of cognitive access to the relations of reliability in question. Lacking such access, such a person will in general have no reason for thinking that the belief is true or likely to be true, but will, on such an account, nonetheless be epistemically justified in according it. Thus such a view arguably marks a major break from the modern epistemological tradition, stemming from Descartes, which identifies epistemic justification with having a reason, perhaps even a conclusive reason for thinking that the belief is true. An epistemologist working within this tradition is likely to feel that the externalist, than offering a competing account of the same concept of epistemic justification with which the traditional epistemologist is concerned, has simply changed the subject.
The main objection to externalism rests on the intuitive certainty that the basic requirement for epistemic justification is that the acceptance of the belief in question be rational or responsible in relation to the cognitive goal of truth, which seems to require in turn that the believer actually be dialectally aware of a reason for thinking that the belief is true (or, at the very least, that such a reason be available to him). Since the satisfaction of an externalist condition is neither necessary nor sufficient for the existence of such a cognitively accessible reason, it is argued, externalism is mistaken as an account of epistemic justification. This general point has been elaborated by appeal to two sorts of putative intuitive counter-examples to externalism. The first of these challenges the necessity of belief which seem intuitively to be justified, but for which the externalist conditions are not satisfied. The standard examples in this sort are cases where beliefs are produced in some very nonstandard way, e.g., by a Cartesian demon, but nonetheless, in such a way that the subjective experience of the believer is indistinguishable from that of someone whose beliefs are produced more normally. The intuitive claim is that the believer in such a case is nonetheless epistemically justified, as much so as one whose belief is produced in a more normal way, and hence that externalist account of justification must be mistaken.
Perhaps the most striking reply to this sort of counter-example, on behalf of a cognitive process is to be assessed in “normal” possible worlds, i.e., in possible worlds that are actually the way our world is common-seismically believed to be, than in the world which contains the belief being judged. Since the cognitive processes employed in the Cartesian demon cases are, for which we may assume, reliable when assessed in this way, the reliabilist can agree that such beliefs are justified. The obvious, to a considerable degree of bringing out the issue of whether it is or not an adequate rationale for this construal of reliabilism, so that the reply is not merely a notional presupposition guised as having representation.
The correlative way of elaborating on the general objection to justificatory externalism challenges the sufficiency of the various externalist conditions by citing cases where those conditions are satisfied, but where the believers in question seem intuitively not to be justified. In this context, the most widely discussed examples have to do with possible occult cognitive capacities, like clairvoyance. Considering the point in application once, again, to reliabilism, the claim is that to think that he has such a cognitive power, and, perhaps, even good reasons to the contrary, is not rational or responsible and therefore not epistemically justified in accepting the belief that result from his clairvoyance, despite the fact that the reliablist condition is satisfied.
One sort of response to this latter sorts of objection is to “bite the bullet” and insist that such believers are in fact justified, dismissing the seeming intuitions to the contrary as latent internalist prejudice. A more widely adopted response attempts to impose additional conditions, usually of a roughly internalist sort, which will rule out the offending example, while stopping far of a full internalism. But, while there is little doubt that such modified versions of externalism can handle particular cases, as well enough to avoid clear intuitive implausibility, the usually problematic cases that they cannot handle, and also whether there is and clear motivation for the additional requirements other than the general internalist view of justification that externalist are committed to reject.
A view in this same general vein, one that might be described as a hybrid of internalism and externalism holds that epistemic justification requires that there is a justicatory factor that is cognitively accessible to the believer in question (though it need not be actually grasped), thus ruling out, e.g., a pure reliabilism. At the same time, however, though it must be objectively true that beliefs for which such a factor is available are likely to be true, in addition, the fact need not be in any way grasped or cognitively accessible to the believer. In effect, of the premises needed to argue that a particular belief is likely to be true, one must be accessible in a way that would satisfy at least weak internalism, the internalist will respond that this hybrid view is of no help at all in meeting the objection and has no belief nor is it held in the rational, responsible way that justification intuitively seems to require, for the believer in question, lacking one crucial premise, still has no reason at all for thinking that his belief is likely to be true.
An alternative to giving an externalist account of epistemic justification, one which may be more defensible while still accommodating many of the same motivating concerns, is to give an externalist account of knowledge directly, without relying on an intermediate account of justification. Such a view will obviously have to reject the justified true belief account of knowledge, holding instead that knowledge is true belief which satisfies the chosen externalist condition, e.g., a result of a reliable process (and perhaps, further conditions as well). This makes it possible for such a view to retain internalist account of epistemic justification, though the centrality of that concept to epistemology would obviously be seriously diminished.
Such an externalist account of knowledge can accommodate the commonsense conviction that animals, young children, and unsophisticated adult's posse's knowledge, though not the weaker conviction (if such a conviction does exist) that such individuals are epistemically justified in their beliefs. It is also at least less vulnerable to internalist counter-examples of the sort discussed, since the intuitions involved there pertain more clearly to justification than to knowledge. What is uncertain is what ultimate philosophical significance the resulting conception of knowledge is supposed to have. In particular, does it have any serious bearing on traditional epistemological problems and on the deepest and most troubling versions of scepticism, which seems in fact to be primarily concerned with justification, the an knowledge?`
A rather different use of the terms “internalism” and “externalism” has to do with the issue of how the content of beliefs and thoughts is determined: According to an internalist view of content, the content of such intention states depends only on the non-relational, internal properties of the individual's mind or grain, and not at all on his physical and social environment: While according to an externalist view, content is significantly affected by such external factors and suggests a view that appears of both internal and external elements is standardly classified as an external view.
As with justification and knowledge, the traditional view of content has been strongly internalist in character. The main argument for externalism derives from the philosophy y of language, more specifically from the various phenomena pertaining to natural kind terms, indexicals, etc. that motivate the views that have come to be known as “direct reference” theories. Such phenomena seem at least to show that the belief or thought content that can be properly attributed to a person is dependant on facts about his environment -, e.g., whether he is on Earth or Twin Earth, what is fact pointing at, the classificatory criteria employed by expects in his social group, etc.-not just on what is going on internally in his mind or brain.
An objection to externalist account of content is that they seem unable to do justice to our ability to know the content of our beliefs or thought “from the inside,” simply by reflection. If content is depending on external factors pertaining to the environment, then knowledge of content should depend on knowledge of these factors-which will not in general be available to the person whose belief or thought is in question.
The adoption of an externalist account of mental content would seem to support an externalist account of justification, by way that if part or all of the content of a belief inaccessible to the believer, then both the justifying status of other beliefs in relation to that content and the status of that content ss justifying further beliefs will be similarly inaccessible, thus contravening the internalist requirement for justification. An internalist must insist that there are no justification relations of these sorts, that our internally associable content can either be justified or justly anything else: But such a response appears lame unless it is coupled with an attempt to show that the externalist account of content is mistaken.
The process of moving from a provisional formulation of acceptance of some position to acceptance of others, is that the goal of logic and classical epistemology is to codify kinds of inference, and to provide principles for separating good from bad inherences.
The rule of reference begins by implicating of question through which it is asked “What the tortoise said to Achilles” in the journal “Mind” in 1895. Lewis Carroll raised the Zeno like problem of how a proof ever gets started.” Suppose I have as premise (1) p and (2) p ➞q. Can I infer q? Only, it seems, if I am sure of (3) (p & p p ➞q) ➞q. Can I then infer q? Only, it seems if I am sure that (4) (p & p ➞q & (p & p ➞q) ➞q) ➞q. For each new axiom (N) I need a further axiom (N. + 1) telling me that the set so far implies q, and the regress never stops, usual solution is to trat a system as containing not only axioms but also rules of reference allow only axioms, but also rules of inference, allowing movement from the axiom. The rule modus ponens slows us to pass from the first two premises to q. Carroll”s puzzle shows that it is essential to distinguish two theoretical categories, although there may be choice bout which theses to put in which category.
For the best of all possibilities that explains inference had first been formulated by Princeton philosopher Gilber Harnam. The idea in that when we have an easy to excavate, the idea is that when we have a best explanation of some phenomenon, we are entitled to repose confidence in it simply on that account. Sometimes thought to br. the lynchpin of scientific method, the principle is not easy to formulate and has come under attack, notably since our best current explanation of something may only be the best of a bad lot. There exist cases in which the best explanation is still not all that convincing, so other considerations than pure explanation success seem to play a role.
The philosopher Bas van Fraassen (The Scientific Image, 1980) explicated further in that constructive empiricism divides science into observation statement and theory statement. It holds that the latter are capable of strict truth and falsity, but maintains that the appropriate attitude is not to believe them, but only to accept them ss best as empirically adequate. It is often regarded as a variety of pragmatism or instrumentalism, although more orthodox varieties of those position deny that theoretic statements have truth-value. A related vie is held by the German philosopher Hans Valhinger (1854-1933), who, however, thinks that we ca be sure that theoretical statements are actually false. , In other words, theories are useful because they enable us to cope with what would otherwise be the unmanageable complexity of things. The doctrine bears some affinity to pragmatism, but differs in that Vaihlinger thinks that our useful theories are nevertheless really false.
Lectures published as Pragmatism, became the new name for old ways of thinking (1907) summed up James”s original contributions to the theory called pragmatism, a term first used by the American logician C. S. Peirce. James generalized the pragmatic method, developing it from a critique of the logical basis of the sciences into a basis for the evaluation of all experience. He maintained that the meaning of ideas is found only in terms of their possible consequences. If consequences are lacking, ideas are meaningless. James contended that this is the method used by scientists to define their terms and to test their hypotheses, which, if meaningful, entail predictions. The hypotheses can be considered true if the predicted events take place. On the other hand, most metaphysical theories are meaningless, because they entail no testable predictions. Meaningful theories, James argued, are instruments for dealing with problems that arise in experience.
According to James”s pragmatism, then, truth is that which works. One determines what works by testing propositions in experience. In so doing, one finds that certain propositions become true. As James put it, “Truth is something that happens to an idea” in the process of its verification; it is not a static property. This does not mean, however, that anything can be true. “The true is only the expedient in the way of our thinking, just as “the right” is only the expedient in the way of our behaving,” James maintained. One cannot believe whatever one want to believe, because such self-centered beliefs would not work out.
James was opposed to absolute metaphysical systems and argued against doctrines that describe reality as a unified, monolithic whole. In Essays in Radical Empiricism (1912), he argued for a pluralistic universe, denying that the world can be explained in terms of an absolute force or scheme that determines the interrelations of things and events. He held that the interrelations, whether they serve to hold things together or apart, are just as real as the things themselves.
By the end of his life, James had become world-famous as a philosopher and psychologist. In both fields, he functioned more as an originator of new thought than as a founder of dogmatic schools. His pragmatic philosophy was further developed by American philosopher John Dewey and others; later studies in physics by Albert Einstein made the theories of interrelations advanced by James appear prophetic.
Nevertheless, in science a way of looking at a field, this, however, as accorded through the lines of force whose evident physical reality o of the intervening medium whereby, the task of the philosopher of science has often been posed in terms of demarcating good or scientific theories from bad, unscientific ones wherefore he property of a statement or theory that it is capable of being refuted by experience. It a proper annunciation is accredited within the philosophy falsifiability, wherein scientific theory, as opposed to unfalsifaiability and noticeably psychoanalysis and historical materialism. The philosopher of science Raimund Karl Popper (1902-1994) whose idea was that it could be a positive virtue is a scientific theory that it is bold, conjectural, and goes beyond the evidence, but that it has to be capable of facing possible refutation. If every way that things turn out is compatible with it, then it is no longer a scientific theory, but for instance, an ideology or article of faith. Popper argued that the central virtue of science, as opposed to pseudo-science, is not that it puts forward the hypotheses that are confirmed by evidence. That is, they genuinely face the possibility of test and rejection through not confirming to evidences so gathered, that is to give no accent of te extent in which it is rational to rely upon scientific theory, however, the actual picture of acceptance and rejection of scientific hypotheses is more complex than Popper suggests. As perhaps, the view that everyday attributions of intention beliefs, and, meanings to other persons proceed via tacit use of a theory that enables one to construct of these interpretations as an explanation of their doing.
The view is commonly held along with “functionalism” according to which psychological states are theoretical entities, identified by te network of their causes ad effects. The theory-theory has different implications, depending upon which feature of theories is being stressed. Theories may be thought of as capable of as yielding predication and explanations, as achieved by a process of theorizing as answering to empirical evidence, that its principle describable without them, as liable to be overturned by newer and better theorise, and so on. The main problem with is with our understanding of others as the outcome of a piece of theorising is the non-existence of medium, in which his theory can be couched as the chid learns simultaneously with the minds language.
Our understanding of others is not gained by the tacit use of a “theory,” enabling us to infer what thoughts or intentions explain their action, but by reliving the situation “in their moccasins” or from their point of view, not thereby understanding what they experienced and thought, and therefore expressed. Understanding others is achieved when we can ourselves deliberate as they did, and hear their words if theory are our own. The suggestion is a modern development of the “verstehe,” the tradition associated with the German philosopher, literary critic and historian Wilhelm Dilthey (1833-1911).
In addition, the hypnotise especially associated with the American philosopher of mind J.A. Fodor, who affirmed strongly that mental processing occurs in a language different from one”s ordinary native language, but underlying and explaining our competence with it. The idea is a development of the “Chomskyan” notion if an innate universal grammar, it is a way of drawing three analogies between the workings of the brain or mind and those of a standard computer, since computer programs are linguistically complex sets of instruction whose execution explains the surface behaviour of the computer. As an explanation of ordinary language learning and competence the hypothecs of thought have not found universal favour. It apparently only explains ordinary representational powers by invoking innate things of the same sort, and it invites the image of the learning infant translating the language surrounding and in back into an innate language whose own powers are a mysterious biological given.
In philosophy, the doctrine that all existence is resolvable into matter or into an attribute or effect of matter. According to this doctrine, matter is the ultimate reality, and the phenomenon of consciousness is explained by physicochemical changes in the nervous system. Materialism is thus the antithesis of idealism, in which the supremacy of mind is affirmed and matter is characterized as an aspect or objectification of mind. Extreme or absolute materialism is known as materialistic monism. According to the mind-stuff theory of monism, as expounded by the British metaphysician W. K. Clifford, in his Elements of Dynamic (1879-87), matters and minds are consubstantial, each being merely an aspect of the other. Philosophical materialism is ancient and has had numerous formulations. The early Greek philosophers subscribed to a variant of materialism known as hylozoism, according to which matter and life are identical. Related to hylozoism is the doctrine of hylotheism, in which matter is held to be divine, or the existence of God is disavowed apart from matter. Cosmological materialism is a term used to characterize a materialistic interpretation of the universe.
Antireligious materialism is motivated by a spirit of hostility toward the theological dogmas of organized religion, particularly those of Christianity. Notable among the exponents of antireligious materialism was the 18th-century French philosopher's Denis Diderot, Paul Henri d'Holbach, and Julien Offroy de La Mettrie. According to historical materialism, as set forth in the writings of Karl Marx, Friedrich Engels, and Vladimir Ilich Lenin, in every historical epoch the prevailing economic system by which the necessities of life are produced determines the form of societal organization and the political, religious, ethical, intellectual, and artistic history of the epoch.
In modern times philosophical materialism has been largely influenced by the doctrine of evolution and may indeed be said to have been assimilated in the wider theory of evolution. Supporters of the theory of evolution go beyond the mere antithesis or atheism of materialism and seek positively to show how the diversities and differences in creation are the result of natural as opposed to supernatural processes.
The Philosophy of Mind is the branch of philosophy that considers mental phenomena such as sensation, perception, thought, belief, desire, intention, memory, emotion, imagination, and purposeful action. These phenomena, which can be broadly grouped as thoughts and experiences, are features of human beings; many of them are also found in other animals. Philosophers are interested in the nature of each of these phenomena as well as their relationships to one another and to physical phenomena, such as motion.
Many fields other than philosophy shares an interest in the nature of mind. In religion, the nature of mind is connected with various conceptions of the soul and the possibility of life after death. In many abstract theories of mind there is considerable overlap between philosophy and the science of psychology. Once part of philosophy, psychology split off and formed a separate branch of knowledge in the 19th century. While psychology used scientific experiments to study mental states and events, philosophy uses reasoned arguments and thought experiments in seeking to understand the concepts that underlie mental phenomena. Also influenced by philosophy of mind is the field of artificial intelligence (AI), which endeavors to develop computers that can mimic what the human mind can do. Cognitive science attempts to integrate the understanding of mind provided by philosophy, psychology, AI, and other disciplines. Finally, all of these fields benefit from the detailed understanding of the brain that has emerged through neuroscience in the late 20th century.
Philosophers use the characteristics of inward accessibility, subjectivity, intentionality, goal-directedness, creativity and freedom, and consciousness to distinguish mental phenomena from physical phenomena.
Perhaps the most important characteristic of mental phenomena is that they are inwardly accessible, or available to us through introspection. We each know our own minds-our sensations, thoughts, memories, desires, and fantasies-in a direct sense, by internal reflection. We also know our mental states and mental events in a way that no one else can. In other words, we have privileged access to our own mental states.
Certain mental phenomena, those we generally call experiences, have a subjective nature-that is, they have certain characteristics we become aware of when we reflect. For instance, there is “something it is like” to feel pain, or have an itch, or see something red. These characteristics are subjective in that they are accessible to the subject of the experience, the person who has the experience, but not to others.
Other mental phenomena, which we broadly refer to as thoughts, have a characteristic philosophers call intentionality. Intentional thoughts are about other thoughts or objects, which are represented as having certain properties or for being related to one another in a certain way. The belief that California is west of Nevada, for example, is about California and Nevada and represents the former being west of the latter. Although we have privileged access to our intentional states, many of them do not seem to have a subjective nature, at least not in the way that experiences do.
A number of mental phenomena appear to be connected to one another as elements in an intelligent, goal-directed system. The system works as follows: First, our sense organs are stimulated by events in our environment; next, by virtue of these stimulations, we perceive things about the external world; finally, we use this information, as well as information we have remembered or inferred, to guide our actions in ways that further our goals. Goal-directedness seems to accompany only mental phenomena.
Another important characteristic of mind, especially of human minds, is the capacity for choice and imagination. Rather than automatically converting past influences into future actions, individual minds are capable of exhibiting creativity and freedom. For instance, we can imagine things we have not experienced and can act in ways that no one expects or could predict.
Mental phenomena are conscious, and consciousness may be the closest term we have for describing what is special about mental phenomena. Minds are sometimes referred to as consciousnesses, yet it is difficult to describe exactly what consciousness is. Although consciousness is closely related to inward accessibility and subjectivity, these very characteristics seem to hinder us in reaching an objective scientific understanding of it.
Although philosophers have written about mental phenomena since ancient times, the philosophy of mind did not garner much attention until the work of French philosopher René Descartes in the 17th century. Descartes”s work represented a turning point in thinking about mind by making a strong distinction between bodies and minds, or the physical and the mental. This duality between mind and body, known as Cartesian dualism, has posed significant problems for philosophy ever since.
Descartes believed there are two basic kinds of things in the world, a belief known as substance dualism. For Descartes, the principles of existence for these two groups of things-bodies and minds-are completely different from one another: Bodies exist by being extended in space, while minds exist by being conscious. According to Descartes, nothing can be done to give a body thought and consciousness. No matter how we shape a body or combine it with other bodies, we cannot turn the body into a mind, a thing that is conscious, because being conscious is not a way of being extended.
For Descartes, a person consists of a human body and a human mind causally interacting with one another. For example, the intentions of a human being may cause that person's limbs to move. In this way, the mind can affect the body. In addition, the sense organs of a human being maybe affected by light, pressure, or sound, external sources, which in turn affect the brain, affecting mental states. Thus, the body may affect the mind. Exactly how mind can affect body, and vice versa, is a central issue in the philosophy of mind, and is known as the mind-body problem. According to Descartes, this interaction of mind and body is peculiarly intimate. Unlike the interaction between a pilot and his ship, the connection between mind and body more closely resembles two substances that have been thoroughly mixed together.
In response to the mind-body problem arising from Descartes”s theory of substance dualism, a number of philosophers have advocated various forms of substance monism, the doctrine that there is ultimately just one kind of thing in reality. In the 18th century, Irish philosopher George Berkeley claimed there were no material objects in the world, only minds and their ideas. Berkeley thought that talk about physical objects was simply a way of organizing the flow of experience. Near the turn of the 20th century, American psychologist and philosopher William James proposed another form of substance monism. James claimed that experience is the basic stuff from which both bodies and minds are constructed.
Most philosophers of mind today are substance monists of a third type: They are materialists who believe that everything in the world is basically material, or a physical object. Among materialists, there is still considerable disagreement about the status of mental properties, which are conceived as properties of bodies or brains. Materialists who are property dualists believe that mental properties are an additional kind of property or attribute, not reducible to physical properties. Property dualists have the problem of explaining how such properties can fit into the world envisaged by modern physical science, according to which there are physical explanations for all things.
Materialists who are property monists believe that there is ultimately only one type of property, although they disagree on whether or not mental properties exist in material form. Some property monists, known as reductive materialists, hold that mental properties exist simply as a subset of relatively complex and nonbasic physical properties of the brain. Reductive materialists have the problem of explaining how the physical states of the brain can be inwardly accessible and have a subjective character, as mental states do. Other property monists, known as Eliminative materialists, consider the whole category of mental properties to be a mistake. According to them, mental properties should be treated as discredited postulates of an outmoded theory. Eliminative materialism is difficult for most people to accept, since we seem to have direct knowledge of our own Philosophy of mind concerns itself with a number of specialized problems. In addition to the mind-body problem, important issues include those of personal identity, immortality, and artificial intelligence.
During much of Western history, the mind has been identified with the soul as presented in Christian Theology. According to Christianity, the soul is the source of a person's identity and is usually regarded as immaterial; thus, it is capable of enduring after the death of the body. Descartes”s conception of the mind as a separate, nonmaterial substance fits well with this understanding of the soul. In Descartes's view, we are aware of our bodies only as the cause of sensations and other mental phenomena. Consequently our personal essence is composed more fundamentally of mind and the preservation of the mind after death would constitute our continued existence.
The mind conceived by materialist forms of substance monism does not fit as neatly with this traditional concept of the soul. With materialism, once a physical body is destroyed, nothing enduring remains. Some philosophers think that a concept of personal identity can be constructed that permits the possibility of life after death without appealing to separate immaterial substances. Following in the tradition of 17th-century British philosopher John Locke, these philosophers propose that a person consists of a stream of mental events linked by memory. These link of memory, rather than a single underlying substance, provide the unity of a single consciousness through time. Immortality is conceivable if we think of these memory links as connecting a later consciousness in heaven with an earlier one on earth.
The field of artificial intelligence also raises interesting questions for the philosophy of mind. People have designed machines that mimic or model many aspects of human intelligence, and there are robots currently in use whose behavior is described in terms of goals, beliefs, and perceptions. Such machines are capable of behavior that, were it exhibited by a human being, would surely be taken to be free and creative. As an example, in 1996 an IBM computer named Deep Blue won a chess game against Russian world champion Garry Kasparov under international match regulations. Moreover, it is possible to design robots that have some sort of privileged access to their internal states. Philosophers disagree over whether such robots truly think or simply appear to think and whether such robots should be considered to be conscious.
Philosophy, a speculative world-view which asserts that basic reality is constantly in a process of flux and change. Indeed, reality is identified with pure process. Concepts such as creativity, freedom, novelty, emergence, and growth are fundamental explanatory categories for process philosophy. This metaphysical perspective is to be contrasted with a philosophy of substance, the view that a fixed and permanent reality underlies the changing or fluctuating world of ordinary experience. Whereas substance philosophy emphasizes static being, process philosophy emphasizes dynamically becoming.
Although process philosophy is as old as the 6th-century Bc Greek philosopher, Heraclitus, renewed interest in it was stimulated in the 19th century by the theory of evolution. Key figures in the development of modern process philosophy were the British philosophers's Herbert Spencer, Samuel Alexander, and Alfred North Whitehead, the American philosopher”s Charles S. Peirce and William James, and the French philosopher's Henri Bergson and Pierre Teilhard de Chardin. Whitehead's Process and Reality: An Essay in Cosmology (1929) is generally considered the most important systematic expression of process philosophy.
A contemporary theology has been strongly influenced by process philosophy. The American theologian Charles Hartshorne, for instance, rather than interpreting God as an unchanging absolute, emphasizes God”s sensitive and caring relationship with the world. A personal God enters into relationships in such a way that he is affected by the relationships, and to be affected by relationships is to change. So God too is in the process of growth and development.
Neurophysiology, is the study of how nerve cells, or neurons, receive and transmit information. Two types of phenomena are involved in processing nerve signals: electrical and chemical. Electrical events propagate a signal within a neuron, and chemical processes transmit the signal from one neuron to another neuron or to a muscle cell.
The signals conveying everything that human beings sense and think, and every motion they make, follows nerve pathways in the human body as waves of ions (atoms or groups of atoms that carries electric charges). Australian physiologist Sir John Eccles discovered many of the intricacies of this electrochemical signaling process, particularly the pivotal step in which a signal is conveyed from one nerve cell to another. He shared the 1963 Nobel Prize in physiology or medicine for this work, which he described in a 1965 Scientific American article.
A neuron is a long cell that has a thick central area containing the nucleus; it also has one long process called an axon and one or more short, bushy processes called dendrites. Dendrites receive impulses from other neurons. (The exceptions are sensory neurons, such as those that transmit information about temperature or touch, in which the signal is generated by specialized receptors in the skin.) These impulses are propagated electrically along the cell membrane to the end of the axon. At the tip of the axon the signal is chemically transmitted to an adjacent neuron or muscle cell.
Like all other cells, neurons contain charged ions: potassium and sodium (positively charged) and chlorine (negatively charged). Neurons differ from other cells in that they are able to produce a nerve impulse. A neuron is polarized-that is, it has an overall negative charge inside the cell membrane because of the high concentration of chlorine ions and low concentration of potassium and sodium ions. The concentration of these same ions is exactly reversed outside the cell. This charge differential represents stored electrical energy, sometimes referred to as membrane potential or resting potential. The negative charge inside the cell is maintained by two features. The first is the selective permeability of the cell membrane, which is more permeable to potassium than sodium. The second feature is sodium pumps within the cell membrane that actively pump sodium out of the cell. When depolarization occurs, this charge differential across the membrane is reversed, and a nerve impulse is produced.
Depolarization is a rapid change in the permeability of the cell membrane. When sensory input or any other kind of stimulating current is received by the neuron, the membrane permeability is changed, allowing a sudden influx of sodium ions into the cell. The high concentration of sodium, or action potential, changes the overalls charge within the cell from negative too positively. The locals change in ion concentration triggers similar reactions along the membrane, propagating the nerve impulse. After a brief period called the refractory period, during which the ionic concentration returned to resting potential, the neuron can repeat this process.
Nerve impulses travel at different speeds, depending on the cellular composition of a neuron. Where speed of impulse is important, as in the nervous system, axons are insulated with a membranous substance called myelin. The insulation provided by myelin maintains the ionic charge over long distances. Nerve impulses are propagated at specific points along the myelin sheath; these points are called the nodes of Ranvier. Examples of myelinated axons are those in sensory nerve fibers and nerves connected to skeletal muscles. In non-myelinated cells, the nerve impulse is propagated more diffusely.
When the electrical signal reaches the tip of an axon, it stimulates small presynaptic vesicles in the cell. These vesicles contain chemicals called neurotransmitters, which are released into the microscopic space between neurons (the synaptic cleft). The neurotransmitters attach to specialized receptors on the surface of the adjacent neuron. This stimulus causes the adjacent cell to depolarize and propagate an action potential of its own. The duration of a stimulus from a neurotransmitter is limited by the breakdown of the chemicals in the synaptic cleft and the reuptake by the neuron that produced them. Formerly, each neuron was thought to make only one transmitter, but recent studies have shown that some cells make two or more.
Philosophy of Mind considers mental phenomena such as sensation, perception, thought, belief, desire, intention, memory, emotion, imagination, and purposeful action. These phenomena, which can be broadly grouped as thoughts and experiences, are features of human beings; many of them are also found in other animals. Philosophers are interested in the nature of each of these phenomena as well as their relationships to one another and to physical phenomena, such as motion.
In the 17th century, French philosopher René Descartes proposed that only two substances ultimately exist; mind and body. Yet, if the two are entirely distinct, as Descartes believed, how can one substance interact with the other? How, for example, is the intention of a human mind able to cause movement in the person's limbs? The issue of the interaction between mind and body is known in philosophy as the mind-body problem.
Many fields other than a philosophy share an interest in the nature of mind. In religion, the nature of mind is connected with various conceptions of the soul and the possibility of life after death. In many abstract theories of mind there is considerable overlap between philosophy and the science of psychology. Once part of philosophy, psychology split off and formed a separate branch of knowledge in the 19th century. While psychology used scientific experiments to study mental states and events, philosophy uses reasoned arguments and thought experiments in seeking to understand the concepts that underlie mental phenomena. Also influenced by philosophy of mind is the field of artificial intelligence (AI), which endeavors to develop computers that can mimic what the human mind can do. Cognitive science attempts to integrate the understanding of mind provided by philosophy, psychology, AI, and other disciplines. Finally, all of these fields benefit from the detailed understanding of the brain that has emerged through neuroscience in the late 20th century.
Philosophers use the characteristics of inward accessibility, subjectivity, intentionality, goal-directedness, creativity and freedom, and consciousness to distinguish mental phenomena from physical phenomena.
Perhaps the most important characteristic of mental phenomena is that they are inwardly accessible, or available to us through introspection. We each know our own minds-our sensations, thoughts, memories, desires, and fantasies-in a direct sense, by internal reflection. We also know our mental states and mental events in a way that no one else can. In other words, we have privileged access to our own mental states.
Certain mental phenomena, those we generally call experiences, have a subjective nature-that is, they have certain characteristics we become aware of when we reflect. For instance, there is “something it is like” to feel pain, or have an itch, or see something red. These characteristics are subjective in that they are accessible to the subject of the experience, the person who has the experience, but not to others.
Other mental phenomena, which we broadly refer to as thoughts, have a characteristic philosophers call intentionality. Intentional thoughts are about other thoughts or objects, which are represented as having certain properties or for being related to one another in a certain way. The belief that California is west of Nevada, for example, is about California and Nevada and represents the former for being west of the latter. Although we have privileged access to our intentional states, many of them do not seem to have a subjective nature, at least not in the way that experiences do.
A number of mental phenomena appear to be connected to one another as elements in an intelligent, goal-directed system. The system works as follows: First, our sense organs are stimulated by events in our environment; next, by virtue of these stimulations, we perceive things about the external world; finally, we use this information, as well as information we have remembered or inferred, to guide our actions in ways that further our goals. Goal-directedness seems to accompany only mental phenomena.
Another important characteristic of mind, especially of human minds, is the capacity for choice and imagination. Rather than automatically converting past influences into future actions, individual minds are capable of exhibiting creativity and freedom. For instance, we can imagine things we have not experienced and can act in ways that no one expects or could predict.
Scientists have long considered the nature of consciousness without producing a fully satisfactory definition. In the early 20th century American philosopher and psychologist William James suggested that consciousness is a mental process involving both attention to external stimuli and short-term memory. Later scientific explorations of consciousness mostly expanded upon James”s work. In this article from a 1997 special issue of Scientific American, Nobel laureate Francis Crick, who helped determine the structure of DNA, and fellow biophysicists Christof Koch explains how experiments on vision might deepen our understanding of consciousness.
Mental phenomena are conscious, and consciousness may be the closest term we have for describing what is special about mental phenomena. Minds are sometimes referred to as consciousnesses, yet it is difficult to describe exactly what consciousness is. Although consciousness is closely related to inward accessibility and subjectivity, these very characteristics seem to hinder us in reaching an objective scientific understanding of it.
Although philosophers have written about mental phenomena since ancient times, the philosophy of mind did not garner much attention until the work of French philosopher René Descartes in the 17th century. Descartes”s work represented a turning point in thinking about mind by making a strong distinction between bodies and minds, or the physical and the mental. This duality between mind and body, known as Cartesian dualism, has posed significant problems for philosophy ever since.
In response to the mind-body problem arising from Descartes”s theory of substance dualism, a number of philosophers have advocated various forms of substance monism, the doctrine that there is ultimately just one kind of thing in reality. In the 18th century, Irish philosopher George Berkeley claimed there were no material objects in the world, only minds and their ideas. Berkeley thought that talk about physical objects was simply a way of organizing the flow of experience. Near the turn of the 20th century, American psychologist and philosopher William James proposed another form of substance monism. James claimed that experience is the basic stuff from which both bodies and minds are constructed.
Most philosophers of mind today are substance monists of a third type: They are materialists who believe that everything in the world is basically material, or a physical object. Among materialists, there is still considerable disagreement about the status of mental properties, which are conceived as properties of bodies or brains. Materialists who are property dualists believe that mental properties are an additional kind of property or attribute, not reducible to physical properties. Property dualists have the problem of explaining how such properties can fit into the world envisaged by modern physical science, according to which there are physical explanations for all things.
Materialists who are property monists believe that there is ultimately only one type of property, although they disagree on whether or not mental properties exist in material form. Some property monists, known as reductive materialists, hold that mental properties exist simply as a subset of relatively complex and nonbasic physical properties of the brain. Reductive materialists have the problem of explaining how the physical states of the brain can be inwardly accessible and have a subjective character, as mental states do. Other property monists, known as Eliminative materialists, consider the whole category of mental properties to be a mistake. According to them, mental properties should be treated as discredited postulates of an outmoded theory. Eliminative materialism is difficult for most people to accept, since we seem to have direct knowledge of our own mental phenomena by introspection and because we use the general principles we understand about mental phenomena to predict and explain the behavior of others.
Philosophy of mind concerns itself with a number of specialized problems. In addition to the mind-body problem, important issues include those of personal identity, immortality, and artificial intelligence.
During much of Western history, the mind has been identified with the soul as presented in Christian Theology. According to Christianity, the soul is the source of a person's identity and is usually regarded as immaterial; thus, it is capable of enduring after the death of the body. Descartes”s conception of the mind as a separate, nonmaterial substance fits well with this understanding of the soul. In Descartes's view, we are aware of our bodies only as the cause of sensations and other mental phenomena. Consequently our personal essence is composed more fundamentally of mind and the preservation of the mind after death would constitute our continued existence.
The mind conceived by materialist forms of substance monism does not fit as neatly with this traditional concept of the soul. With materialism, once a physical body is destroyed, nothing enduring remains. Some philosophers think that a concept of personal identity can be constructed that permits the possibility of life after death without appealing to separate immaterial substances. Following in the tradition of 17th-century British philosopher John Locke, these philosophers propose that a person consists of a stream of mental events linked by memory. These link of memory, rather than a single underlying substance, provide the unity of a single consciousness through time. Immortality is conceivable if we think of these memory links as connecting a later consciousness in heaven with an earlier one on earth.
No simple, agreed-upon definition of consciousness exists. Attempted definitions tend to be tautological (for example, consciousness defined as awareness) or merely descriptive (for example, consciousness described as sensations, thoughts, or feelings). Despite this problem of definition, the subject of consciousness has had a remarkable history. At one time the primary subject matter of psychology, consciousness as an area of study suffered an almost total demise, later reemerging to become a topic of current interest.
Most of the philosophical discussions of consciousness arose from the mind-body issues posed by the French philosopher and mathematician René Descartes in the 17th century. Descartes asked: Is the mind, or consciousness, independent of matter? Is consciousness extended (physical) or unextended (nonphysical)? Is consciousness determinative, or is it determined? English philosophers such as John Locke equated consciousness with physical sensations and the information they provide, whereas European philosophers such as Gottfried Wilhelm Leibniz and Immanuel Kant gave a more central and active role to consciousness.
The philosopher who most directly influenced subsequent exploration of the subject of consciousness was the 19th-century German educator Johann Friedrich Herbart, who wrote that ideas had quality and intensity and that they may inhibit or facilitate one another. Thus, ideas may pass from “states of reality” (consciousness) to “states of tendencies” (unconsciousness), with the dividing line between the two states being described as the threshold of consciousness. This formulation of Herbart clearly presages the development, by the German psychologist and physiologist Gustav Theodor Fechner, of the psychophysical measurement of sensation thresholds, and the later development by Sigmund Freud of the concept of the unconscious.
The experimental analysis of consciousness dates from 1879, when the German psychologist Wilhelm Max Wundt started his research laboratory. For Wundt, the task of psychology was the study of the structure of consciousness, which extended well beyond sensations and included feelings, images, memory, attention, duration, and movement. Because early interest focused on the content and dynamics of consciousness, it is not surprising that the central methodology of such studies was introspection; that is, subjects reported on the mental contents of their own consciousness. This introspective approach was developed most fully by the American psychologist Edward Bradford Titchener at Cornell University. Setting his task as that of describing the structure of the mind, Titchener attempted to detail, from introspective self-reports, the dimensions of the elements of consciousness. For example, taste was “dimensionalized” into four basic categories: sweet, sour, salt, and bitter. This approach was known as structuralism.
By the 1920s, however, a remarkable revolution had occurred in psychology that was to essentially remove considerations of consciousness from psychological research for some 50 years: Behaviorism captured the field of psychology. The main initiator of this movement was the American psychologist John Broadus Watson. In a 1913 article, Watson stated, “I believe that we can write a psychology and never use the term”s consciousness, mental states, mind . . . imagery and the like.” Psychologists then turned almost exclusively to behavior, as described in terms of stimulus and response, and consciousness was totally bypassed as a subject. A survey of eight leading introductory psychology texts published between 1930 and the 1950s found no mention of the topic of consciousness in five texts, and in two it was treated as a historical curiosity.
Beginning in the late 1950s, however, interest in the subject of consciousness returned, specifically in those subjects and techniques relating to altered states of consciousness: sleep and dreams, meditation, biofeedback, hypnosis, and drug-induced states. Much of the surge in sleep and dream research was directly fueled by a discovery relevant to the nature of consciousness. A physiological indicator of the dream state was found: At roughly 90-minute intervals, the eyes of sleepers were observed to move rapidly, and at the same time the sleepers” brain waves would show a pattern resembling the waking state. When people were awakened during these periods of rapid eye movement, they almost always reported dreams, whereas if awakened at other times they did not. This and other research clearly indicated that sleep, once considered a passive state, were instead an active state of consciousness.
During the 1960s, an increased search for “higher levels” of consciousness through meditation resulted in a growing interest in the practices of Zen Buddhism and Yoga from Eastern cultures. A full flowering of this movement in the United States was seen in the development of training programs, such as Transcendental Meditation, that were self-directed procedures of physical relaxation and focused attention. Biofeedback techniques also were developed to bring body systems involving factors such as blood pressure or temperature under voluntary control by providing feedback from the body, so that subjects could learn to control their responses. For example, researchers found that persons could control their brain-wave patterns to some extent, particularly the so-called alpha rhythms generally associated with a relaxed, meditative state. This finding was especially relevant to those interested in consciousness and meditation, and a number of “alpha training” programs emerged.
Another subject that led to increased interest in altered states of consciousness was hypnosis, which involves a transfer of conscious control from the subject to another person. Hypnotism has had a long and intricate history in medicine and folklore and has been intensively studied by psychologists. Much has become known about the hypnotic state, relative to individual suggestibility and personality traits; the subject has now largely been demythologized, and the limitations of the hypnotic state are fairly well known. Despite the increasing use of hypnosis, however, much remains to be learned about this unusual state of focused attention.
Finally, many people in the 1960s experimented with the psychoactive drugs known as hallucinogens, which produce disorders of consciousness. The most prominent of these drugs are lysergic acid diethylamide, or LSD; mescaline; and psilocybin; the latter two have long been associated with religious ceremonies in various cultures. LSD, because of its radical thought-modifying properties, was initially explored for its so-called mind-expanding potential and for its psychotomimetic effects (imitating psychoses). Little positive use, however, has been found for these drugs, and their use is highly restricted.
As the concept of a direct, simple linkage between environment and behavior became unsatisfactory in recent decades, the interest in altered states of consciousness may be taken as a visible sign of renewed interest in the topic of consciousness. That persons are active and intervening participants in their behavior has become increasingly clear. Environments, rewards, and punishments are not simply defined by their physical character. Memories are organized, not simply stored. An entirely new area called cognitive psychology has emerged that centers on these concerns. In the study of children, increased attention is being paid to how they understand, or perceive, the world at different ages. In the field of animal behavior, researchers increasingly emphasize the inherent characteristics resulting from the way a species has been shaped to respond adaptively to the environment. Humanistic psychologists, with a concern for self-actualization and growth, have emerged after a long period of silence. Throughout the development of clinical and industrial psychology, the conscious states of persons in terms of their current feelings and thoughts were of obvious importance. The role of consciousness, however, was often deemphasized in favor of unconscious needs and motivations. Trends can be seen, however, toward a new emphasis on the nature of states of consciousness.
Neurophysiology, is the study of how nerve cells, or neurons, receive and transmit information. Two types of phenomena are involved in processing nerve signals: electrical and chemical. Electrical events propagate a signal within a neuron, and chemical processes transmit the signal from one neuron to another neuron or to a muscle cell.
The signals conveying everything that human beings sense and think, and every motions they make, follow nerve pathways in the human body as waves of ions (atoms or groups of atoms that carries electric charges). Australian physiologist Sir John Eccles discovered many of the intricacies of this electrochemical signaling process, particularly the pivotal step in which a signal is conveyed from one nerve cell to another. He shared the 1963 Nobel Prize in physiology or medicine for this work, which he described in a 1965 Scientific American article.
A neuron is a long cell that has a thick central area containing the nucleus; it also has one long process called an axon and one or more short, bushy processes called dendrites. Dendrites receive impulses from other neurons. (The exceptions are sensory neurons, such as those that transmit information about temperature or touch, in which the signal is generated by specialized receptors in the skin.) These impulses are propagated electrically along the cell membrane to the end of the axon. At the tip of the axon the signal is chemically transmitted to an adjacent neuron or muscle cell.
Like all other cells, neurons contain charged ions: potassium and sodium (positively charged) and chlorine (negatively charged). Neurons differ from other cells in that they are able to produce a nerve impulse. A neuron is polarized-that is, it has an overall negative charge inside the cell membrane because of the high concentration of chlorine ions and low concentration of potassium and sodium ions. The concentration of these same ions is exactly reversed outside the cell. This charge differential represents stored electrical energy, sometimes referred to as membrane potential or resting potential. The negative charge inside the cell is maintained by two features. The first is the selective permeability of the cell membrane, which is more permeable to potassium than sodium. The second feature is sodium pumps within the cell membrane that actively pump sodium out of the cell. When depolarization occurs, this charge differential across the membrane is reversed, and a nerve impulse is produced.
Depolarization is a rapid change in the permeability of the cell membrane. When sensory input or any other kind of stimulating current is received by the neuron, the membrane permeability is changed, allowing a sudden influx of sodium ions into the cell. The high concentration of sodium, or action potential, changes the overall charges within the cell from negative too positively. The local changes in ion concentration triggers similar reactions along the membrane, propagating the nerve impulse. After a brief period called the refractory period, during which the ionic concentration returned to resting potential, the neuron can repeat this process.
Nerve impulses travel at different speeds, depending on the cellular composition of a neuron. Where speed of impulse is important, as in the nervous system, axons are insulated with a membranous substance called myelin. The insulation provided by myelin maintains the ionic charge over long distances. Nerve impulses are propagated at specific points along the myelin sheath; these points are called the nodes of Ranvier. Examples of myelinated axons are those in sensory nerve fibers and nerves connected to skeletal muscles. In non-myelinated cells, the nerve impulse is propagated more diffusely.
When the electrical signal reaches the tip of an axon, it stimulates small presynaptic vesicles in the cell. These vesicles contain chemicals called neurotransmitters, which are released into the microscopic space between neurons (the synaptic cleft). The neurotransmitters attach to specialized receptors on the surface of the adjacent neuron. This stimulus causes the adjacent cell to depolarize and propagate an action potential of its own. The duration of a stimulus from a neurotransmitter is limited by the breakdown of the chemicals in the synaptic cleft and the reuptake by the neuron that produced them. Formerly, each neuron was thought to make only one transmitter, but recent studies have shown that some cells make two or more.
All human emotions-including love, hate, fear, anger, elation, and sadness-are controlled by the brain. It also receives and interprets the countless signals that are sent to it from other parts of the body and from the external environment. The brain makes us conscious, emotional, and intelligent.
The adult human brain is a 1.3-kg. (3-lb.) mass of pinkish-gray jellylike tissue made up of approximately 100 billion nerve cells, or neurons; neuroglia (supporting-tissue) cells; and vascular (blood-carrying) and other tissues.
Between the brain and the cranium-the part of the skull that directly covers the brain-are three protective membranes, or meninges. The outermost membrane, the dura mater, is the toughest and thickest. Below the dura mater is a middle membrane, called the arachnoid layer. The innermost membrane, the pia mater, consists mainly of small blood vessels and follows the contours of the surface of the brain.
A clear liquid, the cerebrospinal fluid, bathes the entire brain and fills a series of four cavities, called ventricles, near the center of the brain. The cerebrospinal fluid protects the internal portion of the brain from varying pressures and transports chemical substances within the nervous system.
From the outside, the brain appears as three distinct but connected parts: the cerebrum (the Latin word for brain)-two large, almost symmetrical hemispheres; the cerebellum (“little brain”)-whose smaller hemispheres located at the back of the cerebrum; and the brain stem-a central core that gradually becomes the spinal cord, exiting the skull through an opening at its base called the foramen magnum. Two other major parts of the brain, the thalamus and the hypothalamus, lie in the midline above the brain stem underneath the cerebellum.
The brain and the spinal cord together make up the central nervous system, which communicates with the rest of the body through the peripheral nervous system. The peripheral nervous system consists of 12 pairs of cranial nerves extending from the cerebrum and brain stem; a system of other nerves branching throughout the body from the spinal cord; and the autonomic nervous system, which regulates vital functions not too conscious control, such as the activity of the heart muscle, smooth muscle (involuntary muscle found in the skin, blood vessels, and internal organs), and glands.
Most high-level brain functions take place in the cerebrum. Its two large hemispheres make up approximately 85 percent of the brain”s weight. The exterior surface of the cerebrum, the cerebral cortex, is a convoluted, or folded, grayish layer of cell bodies known as the gray matter. The gray matter covers an underlying mass of fibers called the white matter. The convolutions are made up of ridgelike bulges, known as gyri, separated by small grooves called sulci and larger grooves called fissures. Approximately two-thirds of the cortical surface is hidden in the folds of the sulci. The extensive convolutions enable a very large surface area of brain cortex-about 1.5 m2 (16 ft2) in an adult-to fit within the cranium. The pattern of these convolutions is similar, although not identical, in all humans.
The two cerebral hemispheres are partially separated from each other by a deep fold known as the longitudinal fissure. Communication between the two hemispheres is through several concentrated bundles of axons, called commissaries, the largest of which is the corpus callosum.
Several major sulci-divide the cortex into distinguishable regions. The central sulcus, or Rolandic fissures, runs from the middle of the top of each hemisphere downward, forward, and toward another major sulcus, the lateral (“side”), or Sylvian, sulcus. These and other sulci and gyri divide the cerebrum into five lobes: the frontal, parietal, temporal, and occipital lobes and the insula.
The frontal lobe is the largest of the five and consists of all the cortex in front of the central sulcus. Broca”s area, a part of the cortex related to speech, is located in the frontal lobe. The parietal lobe consists of the cortex behind the central sulcus to a sulcus near the back of the cerebrum known as the parietocipital sulcus. The parieto-occipital sulcus, in turn, forms the front border of the occipital lobe, which is the rearmost part of the cerebrum. The temporal lobe is to the side of and below the lateral sulcus. Wernicke”s area, a part of the cortex related to the understanding of language, is located in the temporal lobe. The insula lies deep within the folds of the lateral sulcus.
The cerebrum receives information from all the sense organs and sends motor commands (signals that results in activity in the muscles or glands) to other parts of the brain and the rest of the body. Motor commands are transmitted by the motor cortex, a strip of cerebral cortex extending from side to side across the top of the cerebrum just in front of the central sulcus. The sensory cortex, a parallel strips of cerebral cortex just in back of the central sulcus, receives input from the sense organs.
Many other areas of the cerebral cortex have also been mapped according to their specific functions, such as vision, hearing, speech, emotions, language, and other aspects of perceiving, thinking, and remembering. Cortical regions known as associative cortices are responsible for integrating multiple inputs, processing the information, and carrying out complex responses.
The cerebellum coordinates body movements. Located at the lower back of the brain beneath the occipital lobes, the cerebellum is divided into two lateral (side-by-side) lobes connected by a fingerlike bundle of white fibers called the vermis. The outer layer, or cortex, of the cerebellum consists of fine folds called folia. As in the cerebrum, the outer layer of cortical gray matter surrounds a deeper layer of white matter and nuclei (groups of nerve cells). Three fiber bundles called cerebellar peduncles connect the cerebellum to the three parts of the brain stem-the midbrain, the pons, and the medulla oblongata.
The cerebellum coordinates voluntary movements by fine-tuning commands from the motor cortex in the cerebrum. The cerebellum also maintains posture and balance by controlling muscle tone and sensing the position of the limbs. All motor activity, from hitting a baseball to fingering a violin, depends on the cerebellum.
The thalamus and the hypothalamus lie underneath the cerebrum and connect it to the brain stem. The thalamus consist of two rounded masses of gray tissue lying within the middle of the brain, between the two cerebral hemispheres. The thalamus are the main relay station for incoming sensory signals to the cerebral cortex and for outgoing motor signals from it. All sensory input to the brain, except that of the sense of smell, connects to individual nuclei of the thalamus.
The hypothalamus lies beneath the thalamus on the midline at the base of the brain. It regulates or is involved directly in the control of many of the body's vital drives and activities, such as eating, drinking, temperature regulation, sleep, emotional behavior, and sexual activity. It also controls the function of internal body organs by means of the autonomic nervous system, interacts closely with the pituitary gland, and helps coordinate activities of the brain stem.
The brain stem is revolutionarily the most primitive part of the brain and is responsible for sustaining the basic functions of life, such as breathing and blood pressure. It includes three main structures lying between and below the two cerebral hemispheres-the midbrain, pons, and medulla oblongata.
The topmost structure of the brain stem is the midbrain. It contains major relay stations for neurons transmitting signals to the cerebral cortex, as well as many reflex centers-pathways carrying sensory (input) information and motor (output) command. Relay and reflex centers for visual and auditory (hearing) functions are located in the top portion of the midbrain. A pair of nuclei called the superior colliculus control reflex actions of the eye, such as blinking, opening and closing the pupil, and focusing the lens. A second pair of nuclei, called the inferior colliculus, controls auditory reflexes, such as adjusting the ear to the volume of sound. At the bottom of the midbrain are reflex and relay centers relating to pain, temperature, and touch, as well as several regions associated with the control of movement, such as the red nucleus and the substantia nigra and directly in front of the cerebellum is a prominent bulge in the brain stem called the pons. The pons consists of large bundles of nerve fibers that connect the two halves of the cerebellum and also connect each side of the cerebellum with the opposite-side cerebral hemisphere. The pons serves mainly as a relay station linking the cerebral cortex and the medulla oblongata.
The long, stalk-like lowermost portion of the brain stem is called the medulla oblongata. At the top, it is continuous with the pons and the midbrain; at the bottom, it makes a gradual transition into the spinal cord at the foramen magnum. Sensory and motor nerve fibers connecting the brain and the rest of the body cross over to the opposite side as they pass through the medulla. Thus, the left half of the brain communicates with the right half of the body, and the right half of the brain with the left half of the body.
Running up the brain stem from the medulla oblongata through the pons and the midbrain is a netlike formation of nuclei known as the reticular formation. The reticular formation controls respiration, cardiovascular function digestion, levels of alertness, and patterns of sleep. It also determines which parts of the constant flow of sensory information into the body are received by the cerebrum.
There are two main types of brain cells: neurons and neuroglia. Neurons are responsible for the transmission and analysis of all electrochemical communication within the brain and other parts of the nervous system. Each neuron is composed of a cell body called a soma. A major fiber called an axon, and a system of branches called dendrites. Axons, also called nerve fibers, convey electrical signals away from the soma and can be up to 1 m. (3.3 ft.) in length. Most axons are covered with a protective sheath of myelin, a substance made of fats and protein, which insulates the axon. Myelinated axons conduct neuronal signals faster than do unmyelinated axons. Dendrites convey electrical signals toward the soma, are shorter than axons, and are usually multiple and branching.
Neuroglial cells are twice as numerous as neurons and account for half of the brain”s weight. Neuroglia (from glia, Greek for “glue”) provides structural support to the neurons. Neuroglial cells also form myelin, guide developing neurons, take up chemicals involved in cell-to-cell communication, and contribute to the maintenance of the environment around neurons.
Twelve pairs of cranial nerves arise symmetrically from the base of the brain and are numbered, from front to back, in the order in which they arise. They connect mainly with structures of the head and neck, such as the eyes, ears, nose, mouth, tongue, and throat. Some are motor nerves, controlling muscle movement; some are sensory nerves, conveying information from the sense organs; and others contain fibers for both sensory and motor impulses. The first and second pairs of cranial nerves-the olfactory (smell) nerve and the optic (vision) nerve-carry, sensory information from the nose and eyes, respectively, to the undersurface of the cerebral hemispheres. The other ten pairs of cranial nerves originate in or end in the brain stem.
The brain functions by complex neuronal, or nerve cell, circuits. Communication between neurons is both electrical and chemical and always travels from the dendrites of a neuron, through its soma, and out its axon to the dendrites of another neuron.
Dendrites of one neuron receive signals from the axons of other neurons through chemicals known as neurotransmitters. The neurotransmitters set off electrical charges in the dendrites, which then carry the signals electrochemically to the soma. The soma integrates the information, which is then transmitted electrochemically down the axon to its tip.
At the tip of the axon, small, bubble-like structures called vesicles” release neurotransmitters that carry the signal across the synapse, or gap, between two neurons. There are many types of neurotransmitters, including norepinephrine, dopamine, and serotonin. Neurotransmitters can be excitatory (that is, they excite an electrochemical response in the dendrite receptors) or inhibitory (they block the response of the dendrite receptors).
One neuron may communicate with thousands of other neurons, and many thousands of neurons are involved with even the simplest behavior. It is believed that these connections and their efficiency can be modified, or altered, by experience.
Scientists have used two primary approaches to studying how the brain works. One approach is to study brain function after parts of the brain have been damaged. Functions that disappear or that is no longer normal after injury to specific regions of the brain can often be associated with the damaged areas. The second approach is to study the response of the brain to direct stimulation or to stimulation of various sense organs.
Neurons are grouped by function into collections of cells called nuclei. These nuclei are connected to form sensory, motor, and other systems. Scientists can study the function of somatosensory (pain and touch), motor, olfactory, visual, auditory, language, and other systems by measuring the physiological (physical and chemical) change that occur in the brain when these senses are activated. For example, electroencephalography (EEG) measures the electrical activity of specific groups of neurons through electrodes attached to the surface of the skull. Electrodes inserted directly into the brain can give readings of individual neurons. Changes in blood flow, glucose (sugar), or oxygen consumption in groups of active cells can also be mapped.
Although the brain appears symmetrical, how it functions is not. Each hemisphere is specializing and dominates the other in certain functions. Research has shown that hemispheric dominance is related to whether a person is predominantly right-handed or left-handed. In most right-handed people, the left hemisphere processes arithmetic, language, and speech. The right hemisphere interprets music, complex imagery, and spatial relationships and recognizes and expresses emotion. In left-handed people, the pattern of brain organization is more variable.
Hemispheric specialization has traditionally been studied in people who have sustained damage to the connections between the two hemispheres, as may occur with a stroke, an interruption of blood flow to an area of the brain that causes the death of nerve cells in that area. The division of functions between the two hemispheres has also been studied in people who have had to have the connection between the two hemispheres surgically cut in order to control severe epilepsy, a neurological disease characterized by convulsions and loss of consciousness.
The visual system of humans is one of the most advanced sensory systems in the body. More information is conveyed visually than by any other means. In addition to the structures of the eye itself, several cortical regions-collectively called primary visual and visual associative cortices-as well as the midbrain is involved in the visual system. Conscious processing of visual input occurs in the primary visual cortex, but reflexive-that is, immediate and unconscious-responses occur at the superior colliculus in the midbrain. Associative cortical regions-specialized regions that can associate, or integrate, multiple inputs-in the parietal and frontal lobes along with parts of the temporal lobe are also involved in the processing of visual information and the establishment of visual memories.
Language involves specialized cortical regions in a complex interaction that allows the brain to comprehend and communicate abstract ideas. The motor cortex initiates impulses that travel through the brain stem to produce audible sounds. Neighboring regions of motor cortices, called the supplemental motor cortex, are involved in sequencing and coordinating sounds. Broca's area of the frontal lobe is responsible for the sequencing of language elements for output. The comprehension of language is dependent upon Wernicke”s area of the temporal lobe. Other cortical circuits connect these areas.
Memory is usually considered a diffusely stored associative process-that is, it puts together information from many different sources. Although research has failed to identify specific sites in the brain as locations of individual memories, certain brain areas are critical for memory to function. Immediate recall-the ability to repeat short series of words or numbers immediately after hearing them-is thought to be located in the auditory associative cortex. Short-term memory-the ability to retain a limited amount of information for up to an hour-is located in the deep temporal lobe. Long-term memory probably involves exchanges between the medial temporal lobe, various cortical regions, and the midbrain.
The autonomic nervous system regulates the life support systems of the body reflexively-that is, without conscious direction. It automatically controls the muscles of the heart, digestive system, and lungs; certain glands; and homeostasis-that is, the equilibrium of the internal environment of the body. The autonomic nervous system itself is controlled by nerve centers in the spinal cord and brain stem and is fine-tuned by regions higher in the brain, such as the midbrain and cortex. Reactions such as blushing indicate that cognitive, or thinking, centers of the brain are also involved in autonomic responses.
The brain is guarded by several highly developed protective mechanisms. The bony cranium, the surrounding meninges, and the cerebrospinal fluid all contribute to the mechanical protection of the brain. In addition, a filtration system called the blood-brain barrier protects the brain from exposure to potentially harmful substances carried in the bloodstream. Brain disorders have a wide range of causes, including head injury, stroke, bacterial diseases, complex chemical imbalances, and changes associated with aging.
Head injury can initiate a cascade of damaging events. After a blow to the head, a person may be stunned or may become unconscious for a moment. This injury, called a concussion, usually leaves no permanent damage. If the blow is more severe and hemorrhage (excessive bleeding) and swelling occurs, however, severe headache, dizziness, paralysis, a convulsion, or temporary blindness may result, depending on the area of the brain affected. Damage to the cerebrum can also result in profound personality changes.
Damage to Broca”s area in the frontal lobe causes difficulty in speaking and writing, a problem known as Broca”s aphasia. Injury to Wernicke”s area in the left temporal lobe results in an inability to comprehend spoken language, called Wernicke's aphasia.
An injury or disturbance to a part of the hypothalamus may cause a variety of different symptoms, such as loss of appetite with an extreme drop in body weight; increase in appetite leading to obesity; extraordinary thirst with excessive urination (diabetes insipidus); failure in body-temperature control, resulting in either low temperature (hypothermia) or high temperature (fever); excessive emotionality; and uncontrolled anger or aggression. If the relationship between the hypothalamus and the pituitary gland is damaged, other vital bodily functions may be disturbed, such as sexual function, metabolism, and cardiovascular activity.
Injury to the brain stem is even more serious because it houses the nerve centers that control breathing and heart action. Damage to the medulla oblongata usually results in immediate death.
To the brain due to an interruption in blood flow. The interruption may be caused by a blood clot: constriction of a blood vessel, or rupture of a vessel accompanied by bleeding. A pouchlike expansion of the wall of a blood vessel, called an aneurysm, may weaken and burst, for example, because of high blood pressure.
Sufficient quantities of glucose and oxygen, transported through the bloodstream, are needed to keep nerve cells alive. When the blood supply to a small part of the brain is interrupted, the cells in that area die and the function of the area is lost. A massive stroke can cause a one-sided paralysis (hemiplegia) and sensory loss on the side of the body opposite the hemisphere damaged by the stroke.
Epilepsy is a broad term for a variety of brain disorders characterized by seizures, or convulsions. Epilepsy can result from a direct injury to the brain at birth or from a metabolic disturbance in the brain at any time later in life.
Some brain diseases, such as multiple sclerosis and Parkinson disease, are progressive, becoming worse over time. Multiple sclerosis damages the myelin sheath around axons in the brain and spinal cord. As a result, the affected axons cannot transmit nerve impulses properly. Parkinson disease destroys the cells of the substantia nigra in the midbrain, resulting in a deficiency in the neurotransmitter dopamine that affects motor functions.
Cerebral palsy is a broad term for brain damage sustained close to birth that permanently affects motor function. The damage may take place either in the developing fetus, during birth, or just after birth and is the result of the faulty development or breaking down of motor pathways. Cerebral palsy is nonprogressive-that is, it does not worsen with time.
A bacterial infection in the cerebrum or in the coverings of the brain swelling of the brain, or an abnormal growth of healthy brain tissue can all cause an increase in intracranial pressure and result in serious damage to the brain.
Scientists are finding that certain brain chemical imbalances are associated with mental disorders such as schizophrenia and depression. Such findings have changed scientific understanding of mental health and have resulted in new treatments that chemically correct these imbalances.
During childhood development, the brain is particularly susceptible to damage because of the rapid growth and reorganization of nerve connections. Problems that originate in the immature brain can appear as epilepsy or other brain-function problems in adulthood.
Several neurological problems are common in aging. Alzheimer”s disease damages many areas of the brain, including the frontal, temporal, and parietal lobes. The brain tissue of people with Alzheimer's disease shows characteristic patterns of damaged neurons, known as plaques and tangles. Alzheimer's disease produces a progressive dementia, characterized by symptoms such as failing attention and memory, loss of mathematical ability, irritability, and poor orientation in space and time.
Several commonly used diagnostic methods give images of the brain without invading the skull. Some portray anatomy-that is, the structure of the brain-whereas others measure brain function. Two or more methods may be used to complement each other, together providing a more complete picture than would be possible by one method alone.
Magnetic resonance imaging (MRI), introduced in the early 1980s, beams high-frequency radio waves into the brain in a highly magnetized field that causes the protons that form the nuclei of hydrogen atoms in the brain to remit the radio waves. The remitted radio waves are analyzed by computer to create thin cross-sectional images of the brain. MRI provides the most detailed images of the brain and is safer than imaging methods that use X rays. However, MRI is a lengthy process and also cannot be used with people who have pacemakers or metal implants, both of which are adversely affected by the magnetic field.
Computed tomography (CT), also known as CT scans, developed in the early 1970s. This imaging method X-rays the brain from many different angles, feeding the information into a computer that produces a series of cross-sectional images. CT is particularly useful for diagnosing blood clots and brain tumors. It is a much quicker process than magnetic resonance imaging and is therefore advantageous in certain situations-for example, with people who are extremely ill.
Changes in brain function due to brain disorders can be visualized in several ways. Magnetic resonance spectroscopy measures the concentration of specific chemical compounds in the brain that may change during specific behaviors. Functional magnetic resonance imaging (fMRI) maps changes in oxygen concentration that correspond to nerve cell activity.
Positron emission tomography (PET), developed in the mid-1970s, uses computed tomography to visualize radioactive tracers radioactive substances introduced into the brain intravenously or by inhalation. PET can measure such brain functions as cerebral metabolism, blood flow and volume, oxygen use, and the formation of neurotransmitters. Single photon emission computed tomography (SPECT), developed in the 1950s and 1960s, used radioactive tracers to visualize the circulation and volume of blood in the brain.
Brain-imaging studies have provided new insights into sensory, motor, language, and memory processes, as well as brain disorders such as epilepsy cerebrovascular disease; Alzheimer's, Parkinson, and Huntington”s diseases: And the various mental disorders, such as schizophrenia.
In lower vertebrates, such as fish and reptiles, the brain is often tubular and bears a striking resemblance to the early embryonic stages of the brains of more highly evolved animals. In all vertebrates, the brain is divided into three regions: the forebrain (prosencephalon), the midbrain (mesencephalon), and the hindbrain (rhombencephalon). These three regions further subdivide into different structures, systems, nuclei, and layers.
The more highly evolved the animal, the more complex is the brain structure. Human beings have the most complex brains of all animals. Evolutionary forces have also resulted in a progressive increase in the size of the brain. In vertebrates lower than mammals, the brain is small. In meat-eating animals, particularly primates, the brain increases dramatically in size.
The cerebrum and cerebellum of higher mammals are highly convoluted in order to fit the most gray matter surface within the confines of the cranium. Such highly convoluted brains are called gyrencephalic. Many lower mammals have a smooth, or lissencephalic (“smooth head”), cortical surfaces.
There is also evidence of evolutionary adaption of the brain. For example, many birds depend on an advanced visual system to identify food at great distances while in flight. Consequently, their optic lobes and cerebellum are well developed, giving them keen sight and outstanding motor coordination in flight. Rodents, on the other hand, as nocturnal animals, do not have a well-developed visual system. Instead, they rely more heavily on other sensory systems, such as a highly-developed sense of smell and facial whiskers.
Recent research in brain function suggests that there may be sexual differences in both brain anatomy and brain function. One study indicated that men and women may use their brains differently while thinking. Researchers used functional magnetic resonance imaging to observe which parts of the brain were activated as groups of men and women tried to determine whether sets of nonsense words rhymed. Men used only Broca”s area in this task, whereas women used Broca's area plus an area on the right side of the brain.
Both Analytic and Linguistic philosophy, are 20th-century philosophical movements, and dominate most of Britain and the United States since World War II, that aims to clarify language and analyze the concepts expressed in it. The movement has been given a variety of designations, including linguistic analysis, logical empiricism, logical positivism, Cambridge analysis, and “Oxford philosophy.” The last two labels are derived from the universities in England where this philosophical method has been particularly influential. Although no specific doctrines or tenets are accepted by the movement as a whole, analytic and linguistic philosophers agree that the proper activity of philosophy is clarifying language, or, as some prefer, clarifying concepts. The aim of this activity is to settle philosophical disputes and resolve philosophical problems, which, it is argued, originates in linguistic confusion.
A considerable diversity of views exists among analytic and linguistic philosophers regarding the nature of conceptual or linguistic analysis. Some have been primarily concerned with clarifying the meaning of specific words or phrases as an essential step in making philosophical assertions clear and unambiguous. Others have been more concerned with determining the general conditions that must be met for any linguistic utterance to be meaningful; their intent is to establish a criterion that will distinguish between meaningful and nonsensical sentences. Still other analysts have been interested in creating formal, symbolic languages that are mathematical in nature. Their claim is that philosophical problems can be more effectively dealt with once they are formulated in a rigorous logical language.
By contrast, many philosophers associated with the movement have focused on the analysis of ordinary, or natural, language. Difficulties arise when concepts such as time and freedom, for example, are considered apart from the linguistic context in which they normally appear. Attention to language as it is ordinarily used is the key, it is argued, to resolving many philosophical puzzles.
Many experts believe that philosophy as an intellectual discipline originated with the work of Plato, one of the most celebrated philosophers in history. The Greek thinker had an immeasurable influence on Western thought. However, Plato's expression of ideas in the form of dialogues-the dialectical method, used most famously by his teacher Socrates-has led to difficulties in interpreting some of the finer points of his thoughts. The issue of what exactly Plato meant to say is addressed in the following excerpt by author R. M. Hare.
Linguistic analysis as a method of philosophy is as old as the Greeks. Several of the dialogues of Plato, for example, are specifically concerned with clarifying terms and concepts. Nevertheless, this style of philosophizing has received dramatically renewed emphasis in the 20th century. Influenced by the earlier British empirical tradition of John Locke, George Berkeley, David Hume, and John Stuart Mill and by the writings of the German mathematician and philosopher Gottlob Frége, the 20th-century English philosopher's G. E. Moore and Bertrand Russell became the founders of this contemporary analytic and linguistic trend. As students together at the University of Cambridge, Moore and Russell rejected Hegelian idealism, particularly as it was reflected in the work of the English metaphysician F. H. Bradley, who held that nothing is completely real except the Absolute. In their opposition to idealism and in their commitment to the view that careful attention to language is crucial in philosophical inquiry. They set the mood and style of philosophizing for much of the 20th century English-speaking world.
For Moore, philosophy was first and foremost analysis. The philosophical task involves clarifying puzzling propositions or concepts by indicating less puzzling propositions or concepts to which the originals are held to be logically equivalent. Once this task has been completed, the truth or falsity of problematic philosophical assertions can be determined more adequately. Moore was noted for his careful analyses of such puzzling philosophical claims as “time is unreal,” analyses that then aided in determining the truth of such assertions.
Russell, strongly influenced by the precision of mathematics, was concerned with developing an ideal logical language that would accurately reflect the nature of the world. Complex propositions, Russell maintained, can be resolved into their simplest components, which he called atomic propositions. These propositions refer to atomic facts, the ultimate constituents of the universe. The metaphysical views based on this logical analysis of language and the insistence that meaningful propositions must correspond to facts constitute what Russell called logical atomism. His interest in the structure of language also led him to distinguish between the grammatical form of a proposition and its logical form. The statements “John is good” and “John is tall” have the same grammatical form but different logical forms. Failure to recognize this would lead one to treat the property “goodness” as if it were a characteristic of John in the same way that the property “tallness” is a characteristic of John. Such failure results in philosophical confusion.
Austrian-born philosopher Ludwig Wittgenstein was one of the most influential thinkers of the 20th century. With his fundamental work, Tractatus Logico-philosophicus, published in 1921, he became a central figure in the movement known as analytic and linguistic philosophy.
Russell”s work in mathematics attracted at Cambridge, the Austrian philosopher Ludwig Wittgenstein, who became a central figure in the analytic and linguistic movement. In his first major work, Tractatus Logico-philosophicus (1921, translated, 1922), in which he first presented his theory of language, Wittgenstein argued that “all philosophy is a “critique of language” ” and that “philosophy aims at the logical clarification of thoughts.” The results of Wittgenstein's analysis resembled Russell's logical atomism. The world, he argued, is ultimately composed of simple facts, which it is the purpose of language to picture. To be meaningful, statements about the world must be reducible to linguistic utterances that have a structure similar to the simple facts pictured. In this early Wittgensteinian analysis, only propositions that picture facts-the propositions of science-are considered factually meaningful. Metaphysical, theological, and ethical sentences were judged to be factually meaningless.
Influenced by Russell, Wittgenstein, Ernst Mach, and others, a group of philosophers and mathematicians in Vienna in the 1920s initiated the movement known as logical positivism: Led by Moritz Schlick and Rudolf Carnap, the Vienna Circle initiated one of the most important chapters in the history of analytic and linguistic philosophy. According to the positivist, the task of philosophy is the clarification of meaning, not the discovery of new facts (the job of the scientists) or the construction of comprehensive accounts of reality (the misguided pursuit of traditional metaphysics).
The positivist divided all meaningful assertions into two classes: analytic propositions and empirically verifiable ones. Analytic propositions, which include the propositions of logic and mathematics, are statements the truth or falsity of which depended altogether on the meanings of the terms constituting the statement. An example would be the proposition “two plus two equals four.” The second class of meaningful propositions includes all statements about the world that can be verified, at least in principle, by sense experience. Indeed, the meaning of such propositions is identified with the empirical method of their verification. This verifiability theory of meaning, the positivist concluded, would demonstrate that scientific statements are legitimate factual claims and that metaphysical, religious, and ethical sentences are factually empties. The ideas of logical positivism were made popular in England by the publication of A. J. Ayer”s Language, Truth and Logic in 1936.
The positivist” verifiability theory of meaning came under intense criticism by philosophers such as the Austrian-born British philosopher Karl Popper. Eventually this narrow theory of meaning yielded to a broader understanding of the nature of language. Again, an influential figure was Wittgenstein. Repudiating many of his earlier conclusions in the Tractatus, he initiated a new line of thought culminating in his posthumously published Philosophical Investigations (1953; translated, 1953). In this work, Wittgenstein argued that once attention is directed to the way language is actually used in ordinary discourse, the variety and flexibility of language become clear. Propositions do much more than simply picture facts.
This recognition led to Wittgenstein's influential concept of language games. The scientist, the poet, and the theologian, for example, are involved in different language games. Moreover, the meaning of a proposition must be understood in its context, that is, in terms of the rules of the language game of which that proposition is a part. Philosophy, concluded Wittgenstein, is an attempt to resolve problems that arise as the result of linguistic confusion, and the key to the resolution of such problems is ordinary language analysis and the proper use of language.
Additional contributions within the analytic and linguistic movement include the work of the British philosopher's Gilbert Ryle, John Austin, and P. F. Strawson and the American philosopher W. V. Quine. According to Ryle, the task of philosophy is to restate “systematically misleading expressions” in forms that are logically more accurate. He was particularly concerned with statements the grammatical form of which suggests the existence of nonexistent objects. For example, Ryle is best known for his analysis that has of a mental capacity of language, language that misleadingly suggests that the mind is an entity in the same way as the body.
Austin maintained that one of the most fruitful starting points for philosophical inquiry is attention to the extremely fine distinctions drawn in ordinary language. His analysis of language eventually led to a general theory of speech acts, that is, to a description of the variety of activities that an individual may be performing when something is uttered.
Strawson is known for his analysis of the relationship between formal logic and ordinary language. The complexity of the latter, he argued, is inadequately represented by formal logic. A variety of analytic tools, therefore, are needed in addition to logic in analyzing ordinary language.
Quine discussed the relationship between language and ontology. He argued that language systems tend to commit their users to the existence of certain things. For Quine, the justification for speaking one way rather than another is a thoroughly pragmatic one.
The commitment to language analysis as a way of pursuing philosophy has continued as a significant contemporary dimension in philosophy. A division also continues to exist between those who prefer to work with the precision and rigor of symbolic logical systems and those who prefer to analyze ordinary language. Although few contemporary philosophers maintain that all philosophical problems are linguistic, the view continues to be widely held that attention to the logical structure of language and to how language is used in everyday discourse can often aid in resolving philosophical problems.
A loose title for various philosophies that emphasize certain common themes, the individual, the experience of choice, and the absence of rational understandings of the universe, with a consequent dread or sense of “absurdity i9n human life” however, Existentialism is a philosophical movement or tendency, emphasizing individual existence, freedom, and choice, that influenced many diverse writers in the 19th and 20th centuries.
Because of the diversity of positions associated with existentialism, the term is impossible to define precisely. Certain themes common to virtually all existentialist writers can, however, be identified. The term itself suggests one major theme: the stress on concrete individual existence and, consequently, on subjectivity, individual freedom, and choice.
Most philosophers since Plato have held that the highest ethical good are the same for everyone; insofar as one approaches moral perfection, one resembles other morally perfect individuals. The 19th-century Danish philosopher Søren Kierkegaard, who was the first writer to call himself existential, reacted against this tradition by insisting that the highest good for the individual are to find his or her own unique vocation. As he wrote in his journal, “I must find a truth that is true for me . . . the idea for which I can live or die.” Other existentialist writers have echoed Kierkegaard”s belief that one must choose one's own way without the aid of universal, objective standards. Against the traditional view that moral choice involves an objective judgment of right and wrong, Existentialist have argued that no objective, rational basis can be found for moral decisions. The 19th-century German philosopher Friedrich Nietzsche further contended that the individual must decide which situations are to count as moral situations.
All Existentialist have followed Kierkegaard in stressing the importance of passionate individual action in deciding questions of both morality and truth. They have insisted, accordingly, that personal experience and acting on one's own convictions are essential in arriving at the truth. Thus, the understanding of a situation by someone involved in that situation is superior to that of a detached, objective observer. This emphasis on the perspective of the individual agent has also made Existentialist suspicious of systematic reasoning. Kierkegaard, Nietzsche, and other existentialist writers have been deliberately unsystematic in the exposition of their philosophies, preferring to express themselves in aphorisms, dialogues, parables, and other literary forms. Despite their antirationalist position, however, most Existentialist cannot be said to be irrationalists in the sense of denying all validity to rational thought. They have held that rational clarity is desirable wherever possible, but that the most important questions in life are not accessible to reason or science. Furthermore, they have argued that even science is not as rational as is commonly supposed. Nietzsche, for instance, asserted that the scientific assumption of an orderly universe is for the most part a useful fiction.
Perhaps the most prominent theme in existentialist writing is that of choice. Humanity's primary distinction, in the view of most Existentialist, is the freedom to choose. Existentialist have held that human beings do not have a fixed nature, or essence, as other animals and plants do; each human being makes choices that create his or her own nature. In the formulation of the 20th-century French philosopher Jean-Paul Sartre, existence precedes essence. Choice is therefore central to human existence, and it is inescapable; even the refusal to choose is a choice. Freedom of choice entails commitment and responsibility. Because individuals are free to choose their own path, Existentialist have argued, they must accept the risk and responsibility of following their commitment wherever it leads.
Kierkegaard held that it is spiritually crucial to recognize that one experiences not only a fear of specific objects but also a feeling of general apprehension, which he called dread. He interpreted it as God's way of calling each individual to make a commitment to a personally valid way of life. The word anxiety (German Angst) has a similarly crucial role in the work of the 20th-century German philosopher Martin Heidegger; anxiety leads to the individual”s confrontation with nothingness and with the impossibility of finding ultimate justification for the choices he or she must make. In the philosophy of Sartre, the word nausea is used for the individual”s recognition of the pure contingency of the universe, and the word anguish is used for the recognition of the total freedom of choice that confronts the individual at every moment.
Existentialism as a distinct philosophical and literary movement belongs to the 19th and 20th centuries, but elements of existentialism can be found in the thought (and life) of Socrates, in the Bible, and in the work of many premodern philosophers and writers.
The first to anticipate the major concerns of modern existentialism was the 17th-century French philosopher Blaise Pascal. Pascal rejected the rigorous rationalism of his contemporary René Descartes, asserting, in his Pensées (1670), that a systematic philosophy that presumes to explain God and humanity is a form of pride. Like later existentialist writers, he saw human life in terms of paradoxes: The human self, which combines mind and body, is itself a paradox and contradiction.
Kierkegaard, generally regarded as the founder of modern existentialism, reacted against the systematic absolute idealism of the 19th-century German philosopher Georg Wilhelm Friedrich Hegel, who claimed to have worked out a total rational understanding of humanity and history. Kierkegaard, on the contrary, stressed the ambiguity and absurdity of the human situation. The individual”s response to this situation must be to live a totally committed life, and this commitment can only be understood by the individual who has made it. The individual therefore must always be prepared to defy the norms of society for the sake of the higher authority of a personally valid way of life. Kierkegaard ultimately advocated a “leap of faith” into a Christian way of life, which, although incomprehensible and full of risk, was the only commitment he believed could save the individual from despair.
Danish religious philosopher Søren Kierkegaard rejected the all-encompassing, analytical philosophical systems of such 19th-century thinkers as German philosopher G. W. F. Hegel. Instead, Kierkegaard focused on the choices the individual must make in all aspects of his or her life, especially the choice to maintain religious faith. In Fear and Trembling (1846; trans. 1941), Kierkegaard explored the concept of faith through an examination of the biblical story of Abraham and Isaac, in which God demanded that Abraham demonstrate his faith by sacrificing his son.
One of the most controversial works of 19th-century philosophy, Thus Spake Zarathustra (1883-1885) articulated German philosopher Friedrich Nietzsche's theory of the Übermensch, a term translated as “Superman” or “Overman.” The Superman was an individual who overcame what Nietzsche termed the “slave morality” of traditional values, and lived according to his own morality. Nietzsche also advanced his idea that “God is dead,” or that traditional morality was no longer relevant in people”s lives. In this passage, the sage Zarathustra came down from the mountain where he had spent the last ten years alone to preach to the people.
Nietzsche, who was not acquainted with the work of Kierkegaard, influenced subsequent existentialist thought through his criticism of traditional metaphysical and moral assumptions and through his espousal of tragic pessimism and the life-affirming individual will that opposes itself to the moral conformity of the majority. In contrast to Kierkegaard, whose attack on conventional morality led him to advocate a radically individualistic Christianity, Nietzsche proclaimed the “death of God” and went on to reject the entire Judeo-Christian moral tradition in favor of a heroic pagan ideal.
The modern philosophy movements of phenomenology and existentialism have been greatly influenced by the thought of German philosopher Martin Heidegger. According to Heidegger, humankind has fallen into a crisis by taking a narrow, technological approach to the world and by ignoring the larger question of existence. People, if they wish to live authentically, must broaden their perspectives. Instead of taking their existence for granted, people should view themselves as part of Being (Heidegger's terms for that which underlies all existence).
Heidegger, like Pascal and Kierkegaard, reacted against an attempt to put philosophy on a conclusive rationalistic basis-in this case the phenomenology of the 20th-century German philosopher Edmund Husserl. Heidegger argued that humanity finds itself in an incomprehensible, indifferent world. Human beings can never hope to understand why they are here; instead, each individual must choose a goal and follow it with passionate conviction, aware of the certainty of death and the ultimate meaninglessness of one”s life. Heidegger contributed to existentialist thought an original emphasis on being and ontology (see Metaphysics) as well as on language.
Twentieth-century French intellectual Jean-Paul Sartre helped to develop existential philosophy through his writings, novels, and plays. Much of Sartre”s work focuses on the dilemma of choice faced by free individuals and on the challenge of creating meaning by acting responsibly in an indifferent world. In stating that “man is condemned to be free,” Sartre reminds us of the responsibility that accompanies human decisions.
Sartre first gave the term existentialism general currency by using it for his own philosophy and by becoming the leading figure of a distinct movement in France that became internationally influential after World War II. Sartre”s philosophy is explicitly atheistic and pessimistic; he declared that human beings require a rational basis for their lives but are unable to achieve one, and thus human life is a “futile passion.” Sartre nevertheless insisted that his existentialism is a form of humanism, and he strongly emphasized human freedom, choice, and responsibility. He eventually tried to reconcile these existentialist concepts with a Marxist analysis of society and history.
Although existentialist thought encompasses the uncompromising atheism of Nietzsche and Sartre and the agnosticism of Heidegger, its origin in the intensely religious philosophies of Pascal and Kierkegaard foreshadowed its profound influence on 20th-century theologies. The 20th-century German philosopher Karl Jaspers, although he rejected explicit religious doctrines, influenced a contemporary theology through his preoccupation with transcendence and the limits of human experience. The German Protestant theologian”s Paul Tillich and Rudolf Bultmann, the French Roman Catholic theologian Gabriel Marcel, the Russian Orthodox philosopher Nikolay Berdyayev, and the German Jewish philosopher Martin Buber inherited many of Kierkegaard's concerns, especially that a personal sense of authenticity and commitment is essential to religious faith.
Renowned as one of the most important writers in world history, 19th-century Russian author Fyodor Dostoyevsky wrote psychologically intense novels which probed the motivations and moral justifications for his characters” actions. Dostoyevsky commonly addressed themes such as the struggle between good and evil within the human soul and the idea of salvation through suffering. The Brothers Karamazov (1879-1880), generally considered Dostoyevsky's best work, interlaces religious exploration with the story of a family's violent quarrels over a woman and a disputed inheritance.
Also, Maurice Merleau-Ponty (1908-1961), the French existentialist philosopher, whose phenomenological studies of the role of the body in perception and society opened a new field of philosophical investigation. He taught at the University of Lyon, at the Sorbonne, and, after 1952, at the Collège de France. His first important work was The Structure of Comportment (1942; trans. 1963), a critique of behaviorism. His major work, Phenomenology of Perception (1945; trans. 1962), is a detailed study of perception, influenced by the German philosopher Edmund Husserl”s phenomenology and by Gestalt psychology. In it, he argues that science presupposes an original and unique perceptual relation to the world that cannot be explained or even described in scientific terms. This book can be viewed as a critique of cognitivism-the view that the working of the human mind can be understood in terms of rules or programs. It is also a telling critique of the existentialism of his contemporary, Jean-Paul Sartre, showing how human freedom is never total, as Sartre claimed, but is limited by our embodiment.
With Sartre and Simone de Beauvoir, Merleau-Ponty founded an influential postwar French journal, Les Temps Modernes. His brilliant and timely essays on art, film, politics, psychology, and religion, first published in this journal, were later collected in Sense and Nonsense (1948; trans. 1964). At the time of his death, he was working on a book, The Visible and the Invisible (1964; trans. 1968), arguing that the whole perceptual world has the sort of organic unity he had earlier.
A number of existentialist philosophers used literary forms to convey their thought, and existentialism has been as vital and as extensive a movement in literature as in philosophy. The 19th-century Russian novelist Fyodor Dostoyevsky is probably the greatest existentialist literary figure. In Notes from the Underground (1864), the alienated antihero rages against the optimistic assumptions of rationalist humanism. The view of human nature that emerges in this and other novels of Dostoyevsky is that it is unpredictable and perversely self-destructive; only Christian love can save humanity from itself, but such love cannot be understood philosophically. As the character Alyosha says in The Brothers Karamazov (1879-80), “We must love life more than the meaning of it.”
The opening lines of Russian novelist Fyodor Dostoyevsky's Notes from Underground (1864)-“I am a sick man . . . I am a spiteful man”-are among the most famous in 19th-century literature. Published five years after his release from prison and involuntary, military service in Siberia, Notes from Underground is a sign of Dostoyevsky's rejection of the radical social thinking he had embraced in his youth. The unnamed narrator is antagonistic in tone, questioning the reader”s sense of morality as well as the foundations of rational thinking. In this excerpt from the beginning of the novel, the narrator describes himself, derisively referring to himself as an “overly conscious” intellectual.
In the 20th century, the novels of the Austrian Jewish writer Franz Kafka, such as The Trial (1925; trans. 1937) and The Castle (1926; trans. 1930), present isolated men confronting vast, elusive, menacing bureaucracies; Kafka”s themes of anxiety, guilt, and solitude reflect the influence of Kierkegaard, Dostoyevsky, and Nietzsche. The influence of Nietzsche is also discernible in the novels of the French writer”s André Malraux and in the plays of Sartre. The work of the French writer Albert Camus is usually associated with existentialism because of the prominence in it of such themes as the apparent absurdity and futility of life, the indifference of the universe, and the necessity of engagement in a just cause. Existentialist themes are also reflected in the theater of the absurd, notably in the plays of Samuel Beckett and Eugène Ionesco. In the United States, the influence of existentialism on literature has been more indirect and diffuse, but traces of Kierkegaard”s thought can be found in the novels of Walker Percy and John Updike, and various existentialist themes are apparent in the work of such diverse writers as Norman Mailer, John Barth, and Arthur
The problem of defining knowledge in terms of true belief plus some favoured relation between the believer and the facts began with Plato”s view in the Theaetetus, that knowledge is true belief plus some logos, an epistemology is to begin of holding the Foundations of knowledge, a special branches of philosophy that addresses the philosophical problems surrounding the theory of knowledge. Epistemology is concerned with the definition of knowledge and related concepts, the sources and criteria of knowledge, the kinds of knowledge possible and the degree to which each is certain, and the exact relation among the one who knows and the object known.
Thirteenth-century Italian philosopher and theologian Saint Thomas Aquinas attempted to synthesize Christian belief with a broad range of human knowledge, embracing diverse sources such as Greek philosopher Aristotle and Islamic and Jewish scholars. His thought exerted lasting influence on the development of Christian theology and Western philosophy. Author Anthony Kenny examines the complexities of Aquinas”s concepts of substance and accident.
In the 5th century Bc, the Greek Sophists questioned the possibility of reliable and objective knowledge. Thus, a leading Sophist, Gorgias, argued that nothing really exists, that if anything did exist it could not be known, and that if knowledge were possible, it could not be communicated. Another prominent Sophist, Protagoras, maintained that no person”s opinions can be said to be more correct than another”s, because each is the sole judge of his or her own experience. Plato, following his illustrious teacher Socrates, tried to answer the Sophists by postulating the existence of a world of unchanging and invisible forms, or ideas, about which it is possible to have exact and certain knowledge. The thing”s one sees and touches, they maintained, are imperfect copies of the pure forms studied in mathematics and philosophy. Accordingly, only the abstract reasoning of these disciplines yields genuine knowledge, whereas reliance on sense perception produces vague and inconsistent opinions. They concluded that philosophical contemplation of the unseen world of forms is the highest goal of human life.
Aristotle followed Plato in regarding abstract knowledge as superior to any other, but disagreed with him as to the proper method of achieving it. Aristotle maintained that almost all knowledge is derived from experience. Knowledge is gained either directly, by abstracting the defining traits of a species, or indirectly, by deducing new facts from those already known, in accordance with the rules of logic. Careful observation and strict adherence to the rules of logic, which were first set down in systematic form by Aristotle, would help guard against the pitfalls the Sophists had exposed. The Stoic and Epicurean schools agreed with Aristotle that knowledge originates in sense perception, but against both Aristotle and Plato they maintained that philosophy is to be valued as a practical guide to life, rather than as an end in itself.
After many centuries of declining interest in rational and scientific knowledge, the Scholastic philosopher Saint Thomas Aquinas and other philosophers of the Middle Ages helped to restore confidence in reason and experience, blending rational methods with faith into a unified system of beliefs. Aquinas followed Aristotle in regarding perception as the starting point and logic as the intellectual procedure for arriving at reliable knowledge of nature, but he considered faith in scriptural authority as the main source of religious belief.
From the 17th to the late 19th century, the main issue in epistemology was reasoning versus sense perception in acquiring knowledge. For the rationalists, of whom the French philosopher René Descartes, the Dutch philosopher Baruch Spinoza, and the German philosopher Gottfried Wilhelm Leibniz were the leaders, the main source and final test of knowledge was deductive reasoning based on self-evident principles, or axioms. For the empiricist, beginning with the English philosophers Francis Bacon and John Locke, the main source and final test of knowledge was sense perception.
Bacon inaugurated the new era of modern science by criticizing the medieval reliance on tradition and authority and also by setting down new rules of scientific method, including the first set of rules of inductive logic ever formulated. Locke attacked the rationalist belief that the principles of knowledge are intuitively self-evident, arguing that all knowledge is derived from experience, either from experience of the external world, which stamps sensations on the mind, or from internal experience, in which the mind reflects on its own activities. Human knowledge of external physical objects, he claimed, is always subject to the errors of the senses, and he concluded that one cannot have absolutely certain knowledge of the physical world.
Irish-born philosopher and clergyman George Berkeley (1685-1753) argued that everything that human being conceived of exists as an idea in a mind, a philosophical focus which is known as idealism. Berkeley reasoned that because one cannot control one”s thoughts, they must come directly from a larger mind: that of God. In this excerpt from his Treatise Concerning the Principles of Human Knowledge, written in 1710, Berkeley explained why he believed that it is “impossible . . . that there should be any such thing as an outward object.”
The Irish philosopher George Berkeley agreed with Locke, that knowledge comes through ideas, but he denied Locke”s belief that a distinction can be made between ideas and objects. The British philosopher David Hume continued the empiricist tradition, but he did not accept Berkeley”s conclusion that knowledge was of ideas only. He divided all knowledge into two kinds: knowledge of relations of ideas-that is, the knowledge found in mathematics and logic, which is exact and certain but provide no information about the world; and knowledge of matters of fact-that is, the knowledge derived from sense perception. Hume argued that most knowledge of matters of fact depends upon cause and effect, and since no logical connection exists between any given cause and its effect, one cannot hope to know any future matter of fact with certainty. Thus, the most reliable laws of science might not remain true-a conclusion that had a revolutionary impact on philosophy.
The German philosopher Immanuel Kant tried to solve the crisis precipitated by Locke and brought to a climax by Hume; his proposed solution combined elements of rationalism with elements of empiricism. He agreed with the rationalists that one can have exact and certain knowledge, but he followed the empiricist in holding that such knowledge is more informative about the structure of thought than about the world outside of thought. He distinguished three kinds of knowledge: analytical a priori, which is exact and certain but uninformative, because it makes clear only what is contained in definitions; synthetic a posteriori, which conveys information about the world learned from experience, but is subject to the errors of the senses; and synthetic a priori, which is discovered by pure intuition and is both exact and certain, for it expresses the necessary conditions that the mind imposes on all objects of experience. Mathematics and philosophy, according to Kant, provide this last. Since the time of Kant, one of the most frequently argued questions in philosophy has been whether or not such a thing as synthetic a priori knowledge really exists.
During the 19th century, the German philosopher Georg Wilhelm Friedrich Hegel revived the rationalist claim that absolutely certain knowledge of reality can be obtained by equating the processes of thought, of nature, and of history. Hegel inspired an interest in history and a historical approach to knowledge that was further emphasized by Herbert Spencer in Britain and by the German school of historicism. Spencer and the French philosopher Auguste Comte brought attention to the importance of sociology as a branch of knowledge, and both extended the principles of empiricism to the study of society.
The American school of pragmatism, founded by the philosophers Charles Sanders Peirce, William James, and John Dewey at the turn of this century, carried empiricism further by maintaining that knowledge is an instrument of action and that all beliefs should be judged by their usefulness as rules for predicting experiences.
In the early 20th century, epistemological problems were discussed thoroughly, and subtle shades of difference grew into rival schools of thought. Special attention was given to the relation between the act of perceiving something, the object directly perceived, and the thing that can be said to be known as a result of the perception. The phenomenalists contended that the objects of knowledge are the same as the objects perceived. The neorealists argued that one has direct perceptions of physical objects or parts of physical objects, rather than of one's own mental states. The critical realists took a middle position, holding that although one perceives only sensory data such as colors and sounds, these stand for physical objects and provide knowledge thereof.
A method for dealing with the problem of clarifying the relation between the act of knowing and the object known was developed by the German philosopher Edmund Husserl. He outlined an elaborate procedure that he called phenomenology, by which one is said to be able to distinguish the way things appear to be from the way one thinks they really are, thus gaining a more precise understanding of the conceptual foundations of knowledge.
Scientific knowledge reveals that scientific knowledge and method did not spring full-blown from the minds of the ancient Greeks any more than language and culture emerged fully in the minds of Homo sapiens sapient. Scientific knowledge is an extension of ordinary language into greater levels of abstraction and precision through reliance upon geometric and numerical relationships. We speculate that the seeds of the scientific imagination were planted in ancient Greece, as opposed to Chinese or Babylonian culture, partly because the social, political and economic climate in Greece was more open because the social, political, and economic climate in Greece was more open to the pursuit of knowledge with marginal cultural utility. Another important factor was that the special character of Homeric religion allowed the Greeks to invent a conceptual framework that would prove useful in future scientific investigations, but it was only after this inheritance from Greek philosophy was wed to some essential features of Judeo-Christian beliefs about the origin of the cosmos that the paradigm for classical physics emerged.
During the second quarter of the 20th century, two schools of thought emerged, each indebted to the Austrian philosopher Ludwig Wittgenstein. The first of these schools, logical empiricism, or logical positivism, had its origins in Vienna, Austria, but it soon spread to England and the United States. The logical empiricist insisted that there is only one kind of knowledge: scientific knowledge; that any valid knowledge claim must be verifiable in experience; and hence that much that had passed for philosophy was neither true nor false but literally meaningless. Finally, following Hume and Kant, a clear distinction must be maintained between analytic and synthetic statements. The so-called verifiability criterion of meaning has undergone changes as a result of discussions among the logical empiricist themselves, as well as their critics, but has not been discarded. More recently, the sharp distinction between the Analytic and the synthetic has been attacked by a number of philosophers, chiefly by American philosopher W.V.O. Quine, whose overall approach is in the pragmatic tradition.
The latter of these recent schools of thought, generally referred to as linguistic analysis, or ordinary language philosophy, seem to break with traditional epistemology. The linguistic analysts undertake to examine the actual way key epistemological terms are used-terms such as knowledge, perception, and probability-and to formulate definitive rules for their use in order to avoid verbal confusion. British philosopher John Langshaw Austin argued, for example, that to say a statement was truly added but nothing to the statement except a promise by the speaker or writer. Austin does not consider truth a quality or property attaching to statements or utterances. However, the ruling thought is that it is only through a correct appreciation of the role and point of this language that we can come to a better conception of what the language is about, and avoid the oversimplifications and distortion we are apt to bring to its subject matter.
Linguistics is the scientific study of language. It encompasses the description of languages, the study of their origin, and the analysis of how children acquire language and how people learn languages other than their own. Linguistics is also concerned with relationships between languages and with the ways languages change over time. Linguists may study language as a thought process and seek a theory that accounts for the universal human capacity to produce and understand language. Some linguists examine language within a cultural context. By observing talk, they try to determine what a person needs to know in order to speak appropriately in different settings, such as the workplace, among friends, or among family. Other linguists focus on what happens when speakers from different language and cultural backgrounds interact. Linguists may also concentrate on how to help people learn another language, using what they know about the learner”s first language and about the language being acquired.
Although there are many ways of studying language, most approaches belong to one of the two main branches of linguistics: descriptive linguistics and comparative linguistics.
Descriptive linguistics is the study and analysis of spoken language. The techniques of descriptive linguistics were devised by German American anthropologist Franz Boas and American linguist and anthropologist Edward Sapir in the early 1900s to record and analyze Native American languages. Descriptive linguistics begins with what a linguist hears native speakers say. By listening to native speakers, the linguist gathered a body of data and analyzed it in order to identify distinctive sounds, called phonemes. Individual phonemes, such as /p/ and /b/, are established on the grounds that substitution of one for the other changes the meaning of a word. After identifying the entire inventory of sounds in a language, the linguist looks at how these sounds combine to create morphemes, or units of sound that carry meaning, such as the words push and bush. Morphemes may be individual words such as push; root words, such as a berry in blueberry; or prefixes (pre-in preview) and suffixes (-ness in openness).
The linguist”s next step is to see how morphemes combine into sentences, obeying both the dictionary meaning of the morpheme and the grammatical rules of the sentence. In the sentence “She pushed the bush,” the morpheme she, a pronoun, is the subject; push, a transitive verb, is the verb “the”, a definite article, is the determiner; and bush, a noun, is the object. Knowing the function of the morphemes in the sentence enables the linguist to describe the grammar of the language. The scientific procedures of phonemics (finding phonemes), morphology (discovering morphemes), and syntaxes (describing the order of morphemes and their function) provided descriptive linguists with a way to write down grammars of languages never before written down or analyzed. In this way they can begin to study and understand these languages.
Comparative linguistics is the study and analysis, by means of written records, of the origins and relatedness of different languages. In 1786 Sir William Jones, a British scholar, asserted that Sanskrit, Greek, and Latin was related to one another and had descended from a common source. He based this assertion on observations of similarities in sounds and meanings among the three languages. For example, the Sanskrit word bhratar for “brother” resembles the Latin word frater, the Greek word phrater, (and the English word brother).
Other scholars went on to compare Icelandic with Scandinavian languages, and Germanic languages with Sanskrit, Greek, and Latin. The correspondences among languages, known as genetic relationships, came to be represented on what comparative linguists refer to as family trees. Family trees established by comparative linguists include the Indo-European, relating Sanskrit, Greek, Latin, German, English, and other Asian and European languages; the Algonquian, relating Fox, Cree, Menomini, Ojibwa, and other Native North American languages; and the Bantu, relating Swahili, Xhosa, Zulu, Kikuyu, and other African languages.
Comparative linguists also look for similarities in the way words are formed in different languages. Latin and English, for example, change the form of a word to express different meanings, as when the English verb goes interchangeably to go and gone, only to express a past action. Chinese, on the other hand, has no such inflected forms; the verb remains the same while other words indicate the time (as, in “go store tomorrow”). In Swahili, prefixes, suffixes, and infixes (additions in the body of the word) combine with a root word to change its meaning. For example, a single word might expressibly go when something was done, by whom, to whom, and in what manner.
Some comparative linguists reconstruct hypothetical ancestral languages known as proto-languages, which they use to demonstrate relatedness among contemporary languages. A proto-language is not intended to depict a real language, however, and does not represent the speech of ancestors of people speaking modern languages. Unfortunately, some groups have mistakenly used such reconstructions in efforts to demonstrate the ancestral homeland of those people.
Comparative linguists have suggested that certain basic words in a language do not change over time, because people are reluctant to introduce new words for such constants as arm, eye, or mother. These words are termed culture free. By comparing lists of culture-free words in languages within a family, linguists can derive the percentage of related words and use a formula to figure out when the languages separated from one another.
By the 1960s comparativists were no longer satisfied with focusing on origins, migrations, and the family tree method. They challenged as unrealistic the notion that an earlier language could remain sufficiently isolated for other languages to be derived exclusively from it over a period of time. Today comparativists seek to understand the more complicated reality of language history, taking language contact into account. They are concerned with universal characteristics of language and with comparisons of grammars and structures.
The field of linguistics both borrows from and lends its own theories and methods to other disciplines. The many subfields of linguistics have expanded our understanding of languages. Linguistic theories and methods are also used in other fields of study. These overlapping interests have led to the creation of several cross-disciplinary fields.
Sociolinguistics are the study of patterns and variations in language within a society or community. It focuses on the way people use language to express social class, group status, gender, or ethnicity, and it looks at how they make choices about the form of language they use. It also examines the way people use language to negotiate their role in society and to achieve positions of power. For example, sociolinguistic studies have found that the way a New Yorker pronounces the phoneme /r/ in an expression such as “fourth floor” can indicate the person”s social class. According to one study, people aspiring to move from the lower middle classes to the upper middle class attach prestige to pronouncing the /r/. Sometimes they even overcorrect their speech, pronouncing a /r/ where those whom they wish to copy may not.
Some sociolinguists believe that analyzing such variables as the use of a particular phoneme can predict the direction of language change. Change, they say, moves toward the variable associated with power, prestige, or other quality having high social value. Other sociolinguists focus on what happens when speakers of different languages interact. This approach to language change emphasizes the way languages mix rather than the direction of change within a community. The goal of Sociolinguistics is to understand communicative competence-what people need to know to use the appropriate language for a given social setting.
Psycholinguistics merge the fields of psychology and linguistics to study how people process language and how language use is related to underlying mental processes. Studies of children”s language acquisition and of second-language acquisition are psycholinguistic in nature. Psycholinguists work to develop models for how language is processed and understood, using evidence from studies of what happens when these processes go awry. They also study language disorders such as aphasia (impairment of the ability to use or comprehend words) and dyslexia (impairment of the ability to make out written language).
Computational linguistics involves the use of computers to compile linguistic data, analyze languages, translate from one language to another, and develop and test models of language processing. Linguists use computers and large samples of actual language to analyze the relatedness and the structure of languages and to look for patterns and similarities. Computers also aid in stylistic studies, information retrieval, various forms of textual analysis, and the construction of dictionaries and concordances. Applying computers to language studies has resulted in machine translation systems and machines that recognize and produce speech and text. Such machines facilitate communication with humans, including those who are perceptually or linguistically impaired.
Applied linguistics employs linguistic theory and methods in teaching and in research on learning a second language. Linguists look at the errors people make as they learn another language and at their strategies for communicating in the new language at different degrees of competence. In seeking to understand what happens in the mind of the learner, applied linguists recognize that motivation, attitude, learning style, and personality affect how well a person learns another language.
Anthropological linguistics, also known as linguistic anthropology, uses linguistic approaches to analyze culture. Anthropological linguists examine the relationship between a culture and its language. The way cultures and languages have changed over time, and how different cultures and languages are related to one another. For example, the present English use of family and given names arose in the late 13th and early 14th centuries when the laws concerning registration, tenure, and inheritance of property were changed.
Philosophical linguistics examines the philosophy of language. Philosophers of language search for the grammatical principles and tendencies that all human languages share. Among the concerns of linguistic philosophers is the range of possible word order combinations throughout the world. One finding is that 95 percent of the world's languages use a subject-verb-object (SVO) order as English does (“She pushed the bush.”). Only 5 percent use a subject-object-verb (SOV) order or verb-subject-object (VSO) order.
Neurolinguistics are the study of how language is processed and represented in the brain. Neurolinguists seek to identify the parts of the brain involved with the production and understanding of language and to determine where the components of language (phonemes, morphemes, and structure or syntax) are stored. In doing so, they make use of techniques for analyzing the structure of the brain and the effects of brain damage on language.
Speculation about language goes back thousands of years. Ancient Greek philosophers speculated on the origins of language and the relationship between objects and their names. They also discussed the rules that govern language, or grammar, and by the 3rd century Bc they had begun grouping words into parts of speech and devising names for different forms of verbs and nouns.
In India religion provided the motivation for the study of language nearly 2500 years ago. Hindu priests noted that the language they spoke had changed since the compilation of their ancient sacred texts, the Vedas, starting about 1000 Bc. They believed that for certain religious ceremonies based upon the Vedas to succeed, they needed to reproduce the language of the Vedas precisely. Panini, an Indian grammarian who lived about 400 Bc, produced the earliest work describing the rules of Sanskrit, the ancient language of India.
The Romans used Greek grammars as models for their own, adding commentary on Latin style and usage. Statesman and orator Marcus Tullius Cicero wrote on rhetoric and style in the 1st century Bc. Later grammarian’s Aelius Donatus (4th century ad) and Priscian (6th century ad) produced detailed Latin grammars. Roman works served as textbooks and standards for the study of language for more than 1000 years.
It was not until the end of the 18th century that language was researched and studied in a scientific way. During the 17th and 18th centuries, modern languages, such as French and English, replaced Latin as the means of universal communication in the West. This occurrence, along with developments in printing, meant that many more texts became available. At about this time, the study of phonetics, or the sounds of a language, began. Such investigations led to comparisons of sounds in different languages; in the late 18th century the observation of correspondences among Sanskrit, Latin, and Greek gave birth to the field of Indo-European linguistics.
During the 19th century, European linguists focused on philology, or the historical analysis and comparison of languages. They studied written texts and looked for changes over time or for relationships between one language and another.
American linguist, writer, teacher, and political activist Noam Chomsky is considered the founder of transformational-generative linguistic analysis, which revolutionized the field of linguistics. This system of linguistics treats grammar as a theory of language-that is, Chomsky believes that in addition to the rules of grammar specific to individual languages, there are universal rules common to all languages that indicate that the ability to form and understand language is innate to all human beings. Chomsky also is well known for his political activism-he opposed United States involvement in Vietnam in the 1960s and 1970s and has written various books and articles and delivered many lectures in an attempt to educate and empower people on various political and social issues.
In the early 20th century, linguistics expanded to include the study of unwritten languages. In the United States linguists and anthropologists began to study the rapidly disappearing spoken languages of Native North Americans. Because many of these languages were unwritten, researchers could not use historical analysis in their studies. In their pioneering research on these languages, anthropologist’s Franz Boas and Edward Sapir developed the techniques of descriptive linguistics and theorized on the ways in which language shapes our perceptions of the world.
An important outgrowth of descriptive linguistics is a theory known as structuralism, which assumes that language is a system with a highly organized structure. Structuralism began with publication of the work of Swiss linguist Ferdinand de Saussure in Cours de linguistique générale (1916; Course in General Linguistics, 1959). This work, compiled by Saussure”s students after his death, is considered the foundation of the modern field of linguistics. Saussure made a distinction between actual speech, or spoken language, and the knowledge underlying speech that speakers share about what is grammatical. Speech, he said, represents instances of grammar, and the linguist”s task is to find the underlying rules of a particular language from examples found in speech. To the Structuralists, grammar is a set of relationships that account for speech, rather than a set of instances of speech, as it is to the descriptivist.
Once linguists began to study language as a set of abstract rules that somehow account for speech, other scholars began to take an interest in the field. They drew analogies between language and other forms of human behavior, based on the belief that a shared structure underlies many aspects of a culture. Anthropologists, for example, became interested in a Structuralists approach to the interpretation of kinship systems and analysis of myth and religion. American linguist Leonard Bloomfield promoted structuralism in the United States.
Saussure”s ideas also influenced European linguistics, most notably in France and Czechoslovakia (now the Czech Republic). In 1926 Czech linguist Vilem Mathesius founded the Linguistic Circle of Prague, a group that expanded the focus of the field to include the context of language use. The Prague circle developed the field of phonology, or the study of sounds, and demonstrated that universal features of sounds in the languages of the world interrelate in a systematic way. Linguistic analysis, they said, should focus on the distinctiveness of sounds rather than on the ways they combine. Where descriptivists tried to locate and describe individual phonemes, such as /b/ and /p/, the Prague linguists stressed the features of these phonemes and their interrelationships in different languages. In English, for example, the voice distinguishes between the similar sounds of /b/ and /p/, but these are not distinct phonemes in a number of other languages. An Arabic speaker might pronounce the cities Pompei and Bombay the same way.
As linguistics developed in the 20th century, the notion became prevalent that language is more than speech-specifically, that it is an abstract system of interrelationships shared by members of a speech community. Structural linguistics led linguists to look at the rules and the patterns of behavior shared by such communities. Whereas structural linguists saw the basis of language in the social structure, other linguists looked at language as a mental process.
The 1957 publication of Syntactic Structures by American linguist Noam Chomsky initiated what many view as a scientific revolution in linguistics. Chomsky sought a theory that would account for both linguistic structure and the creativity of language-the fact that we can create entirely original sentences and understand sentences never before uttered. He proposed that all people have an innate ability to acquire language. The task of the linguist, he claimed, is to describe this universal human ability, known as language competence, with a grammar from which the grammars of all languages could be derived. The linguist would develop this grammar by looking at the rules children use in hearing and speaking their first language. He termed the resulting model, or grammar, a transformational-generative grammar, referring to the transformations (or rules) that generate (or account for) language. Certain rules, Chomsky asserted, are shared by all languages and form part of a universal grammar, while others are language specific and associated with particular speech communities. Since the 1960s much of the development in the field of linguistics has been a reaction to or against Chomsky”s theories.
At the end of the 20th century, linguists used the term grammar primarily to refer to a subconscious linguistic system that enables people to produce and comprehend an unlimited number of utterances. Grammar thus accounts for our linguistic competence. Observations about the actual language we use, or language performance, are used to theorize about this invisible mechanism known as grammar.
The orientation toward the scientific study of language led by Chomsky has had an impact on nongenerative linguists as well. Comparative and historically oriented linguists are looking for the various ways linguistic universals show up in individual languages. Psycholinguists, interested in language acquisition, are investigating the notion that an ideal speaker-hearer is the origin of the acquisition process. Sociolinguists are examining the rules that underlie the choice of language variants, or codes, and allow for switching from one code to another. Some linguists are studying language performance-the way people use language-see how it reveals a cognitive ability shared by all human beings. Others seek to understand animal communication within such a framework. What mental processes enable chimpanzees to make signs and communicate with one another and how do these processes differ from those of humans?
A written bibliographic note in gratification To Ludwig Wittgenstein (1889-1951), an Austrian-British philosopher, who was one of the most influential thinkers of the 20th century, particularly noted for his contribution to the movement known as analytic and linguistic philosophy.
Born in Vienna on April 26, 1889, Wittgenstein was raised in a wealthy and cultured family. After attending schools in Linz and Berlin, he went to England to study engineering at the University of Manchester. His interest in pure mathematics led him to Trinity College, University of Cambridge, to study with Bertrand Russell. There he turned his attention to philosophy. By 1918 Wittgenstein had completed his Tractatus Logico-philosophicus (1921; trans. 1922), a work he then believed provided the “final solution” to philosophical problems. Subsequently, he turned from philosophy and for several years taught elementary school in an Austrian village. In 1929 he returned to Cambridge to resume his work in philosophy and was appointed to the faculty of Trinity College. Soon he began to reject certain conclusions of the Tractatus and to develop the position reflected in his Philosophical Investigations (pub. posthumously 1953; trans. 1953). Wittgenstein retired in 1947; he died in Cambridge on April 29, 1951. A sensitive, intense man who often sought solitude and was frequently depressed, Wittgenstein abhorred pretense and was noted for his simple style of life and dress. The philosopher was forceful and confident in personality, however, and he exerted considerable influence on those with whom he came in contact.
Wittgenstein”s philosophical life may be divided into two distinct phases: an early period, represented by the Tractatus, and a later period, represented by the Philosophical Investigations. Throughout most of his life, however, Wittgenstein consistently viewed philosophy as linguistic or conceptual analysis. In the Tractatus he argued that “philosophy aims at the logical clarification of thoughts.” In the Philosophical Investigations, however, he maintained that “philosophy is a battle against the bewitchment of our intelligence by means of language.”
Language, Wittgenstein argued in the Tractatus, is composed of complex propositions that can be analyzed into fewer complex propositions until one arrives at simple or elementary propositions. Correspondingly, the world is composed of complex facts that can be analyzed into fewer complex facts until one arrives at simple, or atomic, facts. The world is the totality of these facts. According to Wittgenstein”s picture theory of meaning, it is the nature of elementary propositions logically to picture atomic facts, or “states of affairs.” He claimed that the nature of language required elementary propositions, and his theory of meaning required that there be atomic facts pictured by the elementary propositions. On this analysis, only propositions that picture facts-the propositions of science-are considered cognitively meaningfully. Metaphysical and ethical statements are not meaningful assertions. The logical positivist associated with the Vienna Circle were greatly influenced by this conclusion.
Wittgenstein came to believe, however, that the narrow view of language reflected in the Tractatus was mistaken. In the Philosophical Investigations he argued that if one actually looks to see how language is used, the variety of linguistic usage becomes clear. Words are like tools, and just as tools serve different functions, so linguistic expressions serve many functions. Although some propositions are used to picture facts, others are used to command, question, pray, thank, curse, and so on. This recognition of linguistic flexibility and variety led to Wittgenstein”s concept of a language game and to the conclusion that people play different language games. The scientist, for example, is involved in a different language game than the theologian. Moreover, the meaning of a proposition must be understood in terms of its context, that is, in terms of the rules of the game of which that proposition is a part. The key to the resolution of philosophical puzzles is the therapeutic process of examining and describing language in use.
Analytic and Linguistic Philosophy, is a product out of the 20th-century philosophical movement, and dominant in Britain and the United States since World War II, that aims to clarify language and analyze the concepts expressed in it. The movement has been given a variety of designations, including linguistic analysis, logical empiricism, logical positivism, Cambridge analysis, and “Oxford philosophy.” The last two labels are derived from the universities in England where this philosophical method has been particularly influential. Although no specific doctrines or tenets are accepted by the movement as a whole, analytic and linguistic philosophers agree that the proper activity of philosophy is clarifying language, or, as some prefer, clarifying concepts. The aim of this activity is to settle philosophical disputes and resolve philosophical problems, which, it is argued, originates in linguistic confusion.
A considerable diversity of views exists among analytic and linguistic philosophers regarding the nature of conceptual or linguistic analysis. Some have been primarily concerned with clarifying the meaning of specific words or phrases as an essential step in making philosophical assertions clear and unambiguous. Others have been more concerned with determining the general conditions that must be met for any linguistic utterance to be meaningful; their intent is to establish a criterion that will distinguish between meaningful and nonsensical sentences. Still other analysts have been interested in creating formal, symbolic languages that are mathematical in nature. Their claim is that philosophical problems can be more effectively dealt with once they are formulated in a rigorous logical language.
By contrast, many philosophers associated with the movement have focused on the analysis of ordinary, or natural, language. Difficulties arise when concepts such as time and freedom, for example, are considered apart from the linguistic context in which they normally appear. Attention to language as it is ordinarily used is the key, it is argued, to resolving many philosophical puzzles.
Linguistic analysis as a method of philosophy is as old as the Greeks. Several of the dialogues of Plato, for example, are specifically concerned with clarifying terms and concepts. Nevertheless, this style of philosophizing has received dramatically renewed emphasis in the 20th century. Influenced by the earlier British empirical tradition of John Locke, George Berkeley, David Hume, and John Stuart Mill and by the writings of the German mathematician and philosopher Gottlob Frége, the 20th-century English philosopher”s G. E. Moore and Bertrand Russell became the founders of this contemporary analytic and linguistic trend. As students together at the University of Cambridge, Moore and Russell rejected Hegelian idealism, particularly as it was reflected in the work of the English metaphysician F. H. Bradley, who held that nothing is completely real except the Absolute. In their opposition to idealism and in their commitment to the view that careful attention to language is crucial in philosophical inquiry. They set the mood and style of philosophizing for much of the 20th century English-speaking world.
For Moore, philosophy was first and foremost analysis. The philosophical task involves clarifying puzzling propositions or concepts by indicating fewer puzzling propositions or concepts to which the originals are held to be logically equivalent. Once this task has been completed, the truth or falsity of problematic philosophical assertions can be determined more adequately. Moore was noted for his careful analyses of such puzzling philosophical claims as “time is unreal,” analyses that then aided in determining the truth of such assertions.
Russell, strongly influenced by the precision of mathematics, was concerned with developing an ideal logical language that would accurately reflect the nature of the world. Complex propositions, Russell maintained, can be resolved into their simplest components, which he called atomic propositions. These propositions refer to atomic facts, the ultimate constituents of the universe. The metaphysical views based on this logical analysis of language and the insistence that meaningful propositions must correspond to facts constitute what Russell called logical atomism. His interest in the structure of language also led him to distinguish between the grammatical form of a proposition and its logical form. The statements “John is good” and “John is tall” have the same grammatical form but different logical forms. Failure to recognize this would lead one to treat the property “goodness” as if it were a characteristic of John in the same way that the property “tallness” is a characteristic of John. Such failure results in philosophical confusion.
Russell”s work in mathematics attracted to Cambridge. The Austrian philosopher Ludwig Wittgenstein, who became a central figure in the analytic and linguistic movement. In his first major work, Tractatus Logico-philosophicus (1921; trans. 1922), in which he first presented his theory of language, Wittgenstein argued that “all philosophy is a “critique of language” and that “philosophy aims at the logical clarification of thoughts”. The results of Wittgenstein”s analysis resembled Russell”s logical atomism. The world, he argued, is ultimately composed of simple facts, which it is the purpose of language to picture. To be meaningful, statements about the world must be reducible to linguistic utterances that have a structure similar to the simple facts pictured. In this early Wittgensteinian analysis, only propositions that picture facts-the propositions of science-are considered factually meaningful. Metaphysical, theological, and ethical sentences were judged to be factually meaningless continues to exist between.
Influenced by Russell, Wittgenstein, Ernst Mach, and others, a group of philosophers and mathematicians in Vienna in the 1920s initiated the movement known as logical positivism. Led by Moritz Schlick and Rudolf Carnap, the Vienna Circle initiated one of the most important chapters in the history of analytic and linguistic philosophy. According to the positivist, the task of philosophy is the clarification of meaning, not the discovery of new facts (the job of the scientists) or the construction of comprehensive accounts of reality (the misguided pursuit of traditional metaphysics).
The positivist divided all meaningful assertions into two classes: analytic propositions and empirically verifiable ones. Analytic propositions, which include the propositions of logic and mathematics, are statements the truth or falsity of which depend together on the meanings of the terms constituting the statement. An example would be the proposition “two plus two equals four.” The second class of meaningful propositions includes all statements about the world that can be verified, at least in principle, by sense experience. Indeed, the meaning of such propositions is identified with the empirical method of their verification. This verifiability theory of meaning, the positivist concluded, would demonstrate that scientific statements are legitimate factual claims and that metaphysical, religious, and ethical sentences are factually empties. The ideas of logical positivism were made popular in England by the publication of A.J. Ayer”s Language, Truth and Logic in 1936.
The positivist” verifiability theory of meaning came under intense criticism by philosophers such as the Austrian-born British philosopher Karl Popper. Eventually this narrow theory of meaning yielded to a broader understanding of the nature of language. Again, an influential figure was Wittgenstein. Repudiating many of his earlier conclusions in the Tractatus, he initiated a new line of thought culminating in his posthumously published Philosophical Investigations (1953; trans. 1953). In this work, Wittgenstein argued that once attention is directed to the way language is actually used in ordinary discourse, the variety and flexibility of language become clear. Propositions do much more than simply picture facts.
This recognition led to Wittgenstein”s influential concept of language games. The scientist, the poet, and the theologian, for example, are involved in different language games. Moreover, the meaning of a proposition must be understood in its context, that is, in terms of the rules of the language game of which that proposition is a part. Philosophy, concluded Wittgenstein, is an attempt to resolve problems that arise as the result of linguistic confusion, and the key to the resolution of such problems is ordinary language analysis and the proper use of language.
Additional contributions within the analytic and linguistic movement include the work of the British philosopher's Gilbert Ryle, John Austin, and P. F. Strawson and the American philosopher W. V. Quine. According to Ryle, the task of philosophy is to restate “systematically misleading expressions” in forms that are logically more accurate. He was particularly concerned with statements the grammatical form of which suggests the existence of nonexistent objects. For example, Ryle is best known for his analysis of mentalistic language, language that misleadingly suggests that the mind is an entity in the same way as the body.
Austin maintained that one of the most fruitful starting points for philosophical inquiry is attention to the extremely fine distinctions drawn in ordinary language. His analysis of language eventually led to a general theory of speech acts, that is, to a description of the variety of activities that an individual may be performing when something is uttered.
Strawson is known for his analysis of the relationship between formal logic and ordinary language. The complexity of the latter, he argued, is inadequately represented by formal logic. A variety of analytic tools, therefore, are needed in addition to logic in analyzing ordinary language.
Quine discussed the relationship between language and ontology. He argued that language systems tend to commit their users to the existence of certain things. For Quine, the justification for speaking one way rather than another is a thoroughly pragmatic one.
The commitment to language analysis as a way of pursuing philosophy has continued as a significant contemporary dimension in philosophy. A division also those who prefer to work with the precision and rigor of symbolic logical systems and those who prefer to analyze ordinary language. Although few contemporary philosophers maintain that all philosophical problems are linguistic, the view continues to be widely held that attention to the logical structure of language and to how language is used in everyday discourse can often aid in resolving philosophical problems
Are terms of logical calculus are also called a formal language, and a logical system? A system in which explicit rules are provided to determining (1) which are the expressions of the system (2) which sequence of expressions count as well formed (well-forced formulae) (3) which sequence would count ss proofs. A system may include axioms for which leaves terminate a proof, however, it shows of the prepositional calculus and the predicated calculus.
It”s most immediate of issues surrounding certainty are especially connected with those concerning “scepticism.” Although Greek scepticism entered on the value of enquiry and questioning, scepticism is now the denial that knowledge or even rational belief is possible, either about some specific subject-matter, e.g., ethics, or in any area whatsoever. Classical scepticism, springs from the observation that the best method in some area seems to fall short of giving us contact with the truth, e.g., there is a gulf between appearances and reality, it frequently cites the conflicting judgements that our methods deliver, with the result that questions of truth become undefinable. In classic thought the various examples of this conflict were systemized in the tropes of Aenesidemus. So that, the scepticism of Pyrrho and the new Academy was a system of argument and inasmuch as opposing dogmatism, and, particularly the philosophical system building of the Stoics.
As it has come down to us, particularly in the writings of Sextus Empiricus, its method was typically to cite reasons for finding our issue undesirable (sceptics devoted particular energy to undermining the Stoics conception of some truths as delivered by direct apprehension or some katalepsis). As a result the sceptic concludes eposhé, or the suspension of belief, and then go on to celebrate a way of life whose object was ataraxia, or the tranquillity resulting from suspension of belief.
Fixed by its will for and of itself, the mere mitigated scepticism which accepts every day or commonsense belief, is that, not the delivery of reason, but as due more to custom and habit. Nonetheless, it is self-satisfied at the proper time, however, the power of reason to give us much more. Mitigated scepticism is thus closer to the attitude fostered by the accentuations from Pyrrho through to Sextus Expiricus. Despite the fact that the phrase “Cartesian scepticism” is sometimes used. Descartes himself was not a sceptic, however, in the “method of doubt” uses a sceptical scenario in order to begin the process of finding a general distinction to mark its point of knowledge. Descartes trusts in categories of “clear and distinct” ideas, not far removed from the phantasiá kataleptikê of the Stoics.
For many sceptics had traditionally held that knowledge requires certainty, artistry. And, of course, they claim that certain knowledge is not possible. In part, nonetheless, of the principle that every effect it's a consequence of an antecedent cause or causes. For causality to be true it is not necessary for an effect to be predictable as the antecedent causes may be numerous, too complicated, or too interrelated for analysis. Nevertheless, in order to avoid scepticism, this participating sceptic has generally held that knowledge does not require certainty. Except for alleged cases of things that are evident for one just by being true. It has often been thought, that any thing known must satisfy certain criteria as well for being true. It is often taught that anything is known must satisfy certain standards. In so saying, that by “deduction” or “induction,” there will be criteria specifying when it is. As these alleged cases of self-evident truths, the general principle specifying the sort of consideration that will make such standards in the apparent or justly conclude in accepting it warranted to some degree.
Besides, there is another view-the absolute globular view that we do not have any knowledge whatsoever. In whatever manner, it is doubtful that any philosopher seriously entertains of an absolute scepticism. Even the Pyrrhonist sceptics, who held that we should refrain from accenting to any non-evident standards that no such hesitancy about asserting to “the evident,” the non-evident is any belief that requires evidences because it is warranted.
René Descartes (1596-1650), in his sceptical guise, never doubted the content of his own ideas. It”s challenging logic, inasmuch as of whether they “corresponded” to anything beyond ideas.
All the same, Pyrrhonism and Cartesian form of a virtual globular scepticism, in having been held and defended, that of assuming that knowledge is some form of true, sufficiently warranted belief, it is the warranted condition that provides the truth or belief conditions, in that of providing the grist for the sceptic”s mill about. The Pyrrhonist will suggest that no non-evident, empirically deferring the sufficiency of giving in but warranted. Whereas, a Cartesian sceptic will agree that no empirical standard about anything other than one”s own mind and its contents is sufficiently warranted, because there are always legitimate grounds for doubting it. Whereby, the essential difference between the two views concerns the stringency of the requirements for a belief being sufficiently warranted to take account of as knowledge.
A Cartesian requires certainty. A Pyrrhonist merely requires that the standards in case are more warranted then its negation.
Cartesian scepticism was by an unduly influence with which Descartes agues for scepticism, than his reply holds, in that we do not have any knowledge of any empirical standards, in that of anything beyond the contents of our own minds. The reason is roughly in the position that there is a legitimate doubt about all such standards, only because there is no way to justifiably deny that our senses are being stimulated by some sense, for which it is radically different from the objects which we normally think, in whatever manner they affect our senses. Therefrom, if the Pyrrhonist are the agnostic, the Cartesian sceptic is the atheist.
Because the Pyrrhonist require much less of a belief in order for it to be confirmed as knowledge than do the Cartesian, the argument for Pyrrhonism are much more difficult to construct. A Pyrrhonist must show that there is no better set of reasons for believing to any standards, of which are in case that any knowledge learnt of the mind is understood by some of its forms, that has to require certainty.
The underlying latencies that are given among the many derivative contributions as awaiting their presence to the future that of specifying to the theory of knowledge, is, but, nonetheless, the possibility to identify a set of shared doctrines, however, identity to discern two broad styles of instances to discern, in like the manner, these two styles of pragmatism, clarify the innovation that a Cartesian approval is fundamentally flawed, nonetheless, of responding very differently but not fordone.
Repudiating the requirements of absolute certainty or knowledge, insisting on the connection of knowledge with activity, as, too, of pragmatism of a reformist distributing knowledge upon the legitimacy of traditional questions about the truth-unconductiveness of our cognitive practices, and sustain a conception of truth objectives, enough to give those questions that undergo of a gathering in their own purposive latencies, yet we are given to the spoken word for which a dialectic awareness sparks the flame from the ambers of fire.
Pragmatism of a determinant revolution, by contrast, relinquishing the objectivity of youth, acknowledges no legitimate epistemological questions over and above those that are naturally kindred of our current cognitive conviction.
It seems clear that certainty is a property that can be assembled to either a person or a belief. We can say that a person, “S” is certain, or we can say that its descendable alinement are aligned as of “p”, is certain. The two uses can be connected by saying that “S” has the right to be certain just in case the value of “p” is sufficiently verified.
In defining certainty, it is crucial to note that the term has both an absolute and relative sense. More or less, we take a proposition to be certain when we have no doubt about its truth. We may do this in error or unreasonably, but objectively a proposition is certain when such absence of doubt is justifiable. The sceptical tradition in philosophy denies that objective certainty is often possible, or ever possible, either for any proposition at all, or for any proposition from some suspect family (ethics, theory, memory, empirical judgement etc.) a major sceptical weapon is the possibility of upsetting events that Can cast doubt back onto what were hitherto taken to be certainties. Others include reminders of the divergence of human opinion, and the fallible source of our confidence. Fundamentalist approaches to knowledge look for a basis of certainty, upon which the structure of our system is built. Others reject the metaphor, looking for mutual support and coherence, without foundation.
However, in moral theory, the view that there are inviolable moral standards or absolute variable human desires or policies or prescriptions.
In spite of the notorious difficulty of reading Kantian ethics, a hypothetical imperative embeds a command which is in place only given some antecedent desire or project: “If you want to look wise, stay quiet”. The injunction to stay quiet only applies to those with the antecedent desire or inclination. If one has no desire to look wise the injunction cannot be so avoided: It is a requirement that binds anybody, regardless of their inclination. It could be represented as, for example, “tell the truth (regardless of whether you want to or not)”. The distinction is not always signalled by presence or absence of the conditional or hypothetical form: “If you crave drink, don't become a bartender” may be regarded as an absolute injunction applying to anyone, although only activated in case of those with the stated desire.
In Grundlegung zur Metaphsik der Sitten (1785), Kant discussed five forms of the categorical imperative: (1) the formula of universal law: “act only on that maxim through which you can at the same times will that it should become universal law: (2) the formula of the law of nature: “act as if the maxim of your action were to become through your will a universal law of nature”: (3) the formula of the end-in-itself: “act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but always at the same time as an end”: (4) the formula of autonomy, or considering “the will of every rational being as a will which makes universal law”: (5) the formula of the Kingdom of Ends, which provides a model for the systematic union of different rational beings under common laws.
Even so, a proposition that is not a conditional “p”. Moreover, the affirmative and negative, modern opinion is wary of this distinction, since what appears categorical may vary notation. Apparently, categorical propositions may also turn out to be disguised conditionals: “X” is intelligent (categorical?) = if “X” is given a range of tasks she performs them better than many people (conditional?) The problem. Nonetheless, is not merely one of classification, since deep metaphysical questions arise when facts that seem to be categorical and therefore solid, come to seem by contrast conditional, or purely hypothetical or potential.
A limited area of knowledge or endeavour to which pursuits, activities and interests are a central representation held to a concept of physical theory. In this way, a field is defined by the distribution of a physical quantity, such as temperature, mass density, or potential energy y, at different points in space. In the particularly important example of force fields, such as gravitational, electrical, and magnetic fields, the field value at a point is the force which a test particle would experience if it were located at that point. The philosophical problem is whether a force field is to be thought of as purely potential, so the presence of a field merely describes the propensity of masses to move relative to each other, or whether it should be thought of in terms of the physically real modifications of a medium, whose properties result in such powers that is, are force fields purely potential, fully characterized by dispositional statements or conditionals, or are they categorical or actual? The former option seems to require within ungrounded dispositions, or regions of space that differs only in what happens if an object is placed there. The law-like shape of these dispositions, apparent for example in the curved lines of force of the magnetic field, may then seem quite inexplicable. To atomists, such as Newton it would represent a return to Aristotelian entelechies, or quasi-psychological affinities between things, which are responsible for their motions. The latter option requires understanding of how forces of attraction and repulsion can be “grounded” in the properties of the medium.
The basic idea of a field is arguably present in Leibniz, who was certainly hostile to Newtonian atomism. Although his equal hostility to “action at a distance” muddies the water. It is usually credited to the Jesuit mathematician and scientist Joseph Boscovich (1711-87) and Immanuel Kant (1724-1804), both of whom influenced the scientist Faraday, with whose work the physical notion became established. In his paper “On the Physical Character of the Lines of Magnetic Force” (1852). Faraday was to suggest several criteria for assessing the physical reality of lines of force, such as whether they are affected by an intervening material medium, whether the motion depends on the nature of what is placed at the receiving end. As far as electromagnetic fields go, Faraday himself inclined to the view that the mathematical similarity between heat flow, currents, and electro-magnetic lines of force was evidence for the physical reality of the intervening medium.
Once, again, our mentioning recognition for which its case value, whereby its view is especially associated the American psychologist and philosopher William James (1842-1910), that the truth of a statement can be defined in terms of a “utility” of accepting it. Communicated, so much as a dispiriting position for which its place of valuation may be viewed as an objection. Since there are things that are false, as it may be useful to accept, and conversely there are things that are true and that it may be damaging to accept. Nevertheless, there are deep connections between the idea that a representation system is accorded, and the likely success of the projects in progressive formality, by its possession. The evolution of a system of representation either perceptual or linguistic, seems bounded to connect successes with everything adapting or with utility in the modest sense. The Wittgenstein doctrine stipulates the meaning of use that upon the nature of belief and its relations with human attitude, emotion and the idea that belief in the truth on one hand, the action of the other. One way of binding with cement, wherefore the connection is found in the idea that natural selection becomes much as much in adapting us to the cognitive creatures, because beliefs have effects, they work. Pragmatism can be found in Kant”s doctrine, and continued to play an influencing role in the theory of meaning and truth.
James, (1842-1910), although with characteristic generosity exaggerated in his debt to Charles S. Peirce (1839-1914), he charted that the method of doubt encouraged people to pretend to doubt what they did not doubt in their hearts, and criticize its individualist”s insistence, that the ultimate test of certainty is to be found in the individuals personalized consciousness.
From his earliest writings, James understood cognitive processes in teleological terms. Though, he held us in the satisfactory interests. His will to Believe doctrine, the view that we are sometimes justified in believing beyond the evidential relics upon the notion that a belief's benefits are relevant to its justification. His pragmatic method of analysing philosophical problems, for which requires that we find the meaning of terms by examining their application to objects in experimental situations, similarly reflects the teleological approach in its attention to consequences.
Such an approach, however, sets ”James” theory of meaning apart from verification, dismissive of metaphysics. Unlike the verification alist, who takes cognitive meaning to be a matter only of consequences in sensory experience. James” took pragmatic meaning to include emotional and matter responses. Moreover, his ,metaphysical standard of value, not a way of dismissing them as meaningless. It should also be noted that in a greater extent, circumspective moment's James did not hold that even his broad set of consequences were exhaustive of a terms meaning. “Theism”, for example, he took to have antecedently, definitional meaning, in addition to its varying degree of importance and chance upon an important pragmatic meaning.
James” theory of truth reflects upon his teleological conception of cognition, by considering a true belief to be one which is compatible with our existing system of beliefs, and leads us to satisfactory interaction with the world.
However, Peirce”s famous pragmatist principle is a rule of logic employed in clarifying our concepts and ideas. Consider the claim the liquid in a flask is an acid, if, we believe this, we except that it would turn red: We accept an action of ours to have certain experimental results. The pragmatic principle holds that listing the conditional expectations of this kind, in that we associate such immediacy with applications of a conceptual representation that provides a complete and orderly sets clarification of the concept. This is relevant ti the logic of abduction: Clarificationists using the pragmatic principle provides all the information about the content of a hypothesis that is relevantly to decide whether it is worth testing.
To a greater extent, and what is most important, is the famed apprehension of the pragmatic principle, in so that, Pierces”s account of reality: When we take something to be rea that by this single case, we think it is “fated to be agreed upon by all who investigate” the matter to which it stand, in other words, if I believe that it is really the case that “P”, then I except that if anyone were to inquire depthfully into the finding its measure into whether “p”, they would arrive at the belief that “p”. It is not part of the theory that the experimental consequences of our actions should be specified by a warranted empiricist vocabulary-Peirce insisted that perceptual theories are abounding in latency. Even so, nor is it his view that the collected conditionals do or not clarify a concept as all analytic. In addition, in later writings, he argues that the pragmatic principle could only be made plausible to someone who accepted its metaphysical realism: It requires that “would-bees” are objective and, of course, real.
If realism itself can be given a fairly quick clarification, it is more difficult to chart the various forms of supposition, for they seem legendary. Other opponents deny that the entitles posited by the relevant discourse that exist or at least exists: The standard example is “idealism”, which reality is somehow mind-curative or mind-co-ordinated-that real object comprising the “external world” are not independently of eloping minds, but only exist as in some way correlative to the mental operations. The doctrine assembled of “idealism” enters on the conceptual note that reality as we understand this as meaningful and reflects the working of mindful purposes. And it construes this as meaning that the inquiring mind itself makes of a formative constellations and not of any mere understanding of the nature of the “real” bit even the resulting charger we attribute to it.
Wherefore, the term ids most straightforwardly used when qualifying another linguistic form of Grammatik: a real “x” may be contrasted with a fake, a failed “x”, a near “x”, and so on. To trat something as real, without qualification, is to suppose it to be part of the actualized world. To reify something is to suppose that we have committed by some indoctrinated treatise, as that of a theory. The central error in thinking of reality and the totality of existence is to think of the “unreal” as a separate domain of things, perhaps, unfairly to that of the benefits of existence.
Such that non-existence of all things, as the product of logical confusion of treating the term “nothing” as itself a referring expression instead of a “quantifier”. (Stating informally as a quantifier is an expression that reports of a quantity of times that a predicate is satisfied in some class of things, i.e., in a domain.) This confusion leads the unsuspecting to think that a sentence such as “Nothing is all around us” talks of a special kind of thing that is all around us, when in fact it merely denies that the predicate “is all around us” has appreciations. The feelings that lad some philosophers and theologians, notably Heidegger, to talk of the experience of. Nothing, is not properly the experience of anything, but rather the failure of a hope or expectations that there would be something of some kind at some point. This may arise in quite everyday cases, as when one finds that the article of functions one expected to see as usual, in the corner has disappeared. The difference between “existentialist” and “analytic philosophy”, on the point of what, whereas the former is afraid of nothing, and the latter thinks that there is nothing to be afraid of.
A rather different set of concerns arise when actions are specified in terms of doing nothing, saying nothing may be an admission of guilt, and doing nothing in some circumstances may be tantamount to murder. Still, other substitutional problems arise over conceptualizing empty space and time.
Whereas, the standard opposition between those who affirm and those who deny, the real existence of some kind of thing or some kind of fact or state of affairs. Almost any area of discourse may be the focus of this dispute: The external world, the past and future, other minds, mathematical objects, possibilities, universals, moral or aesthetic properties are examples. There be to one influential suggestion, as associated with the British philosopher of logic and language, and the most determinative of philosophers centred round Anthony Dummett (1925), to which is borrowed from the “intuitionistic” critique of classical mathematics, and suggested that the unrestricted use of the “principle of bivalence” is the trademark of “realism”. However, this ha to overcome counter-examples both ways: Although Aquinas wads a moral “realist”, he held that moral really was not sufficiently structured to make true or false every moral claim. Unlike Kant who believed that he could use the law of bivalence happily in mathematics, precisely because it wad only our own construction. Realism can itself be subdivided: Kant, for example, combines empirical realism (within the phenomenal world the realist says the right things-surrounding objects really exist and independent of us and our mental stares) with transcendental idealism (the phenomenal world as a whole reflects the structures imposed on it by the activity of our minds as they render it intelligible to us). In modern philosophy the orthodox oppositions to realism has been from philosopher such as Goodman, who, impressed by the extent to which we perceive the world through conceptual and linguistic lenses of our own making.
Assigned to the modern treatment of existence in the theory of “quantification” is sometimes put by saying that existence is not a predicate. The idea is that the existential quantifies themselves as an operator on a predicate, indicating that the property it expresses has instances. Existence is therefore treated as a second-order property, or a property of properties. It is fitting to say, that in this it is like number, for when we say that these things of a kind, we do not describe the thing (ad we would if we said there are red things of the kind), but instead attribute a property to the kind itself. The parallelled numbers are exploited by the German mathematician and philosopher of mathematics Gottlob Frége in the dictum that affirmation of existence is merely denied of the number nought. A problem, nevertheless, proves accountable for it”s crated by sentences like “This exists”, where some particular thing is undirected, such that a sentence seems to express a contingent truth (for this insight has not existed), yet no other predicate is involved. “This exists” is, and unlike “Tamed tigers exist”, where a property is said to have an instance, for the word “this” and does not locate a property, but only an individual.
Possible worlds seem able to differ from each other purely in the presence or absence of individuals, and not merely in th distribution of exemplification of properties.
The philosophical ponderance over which to set upon the unreal, as belonging to the domain of Being. Nonetheless, there is little for us that can be said with the philosopher”s study. So it is not apparent that there can be such a subject for being by itself. Nevertheless, the concept had a central place in philosophy from Parmenides to Heidegger. The essential question of “why is there something and not of nothing?" Prompting over logical reflection on what it is for a universal to have an instance, nd as long history of attempts to explain contingent existence, by which id to reference and a necessary ground.
In the transition, ever since Plato, this ground becomes a self-sufficient, perfect, unchanging, and external something, identified with the Good or God, but whose relation with the everyday world remains obscure. The celebrated argument for the existence of God first propounded by Anselm in his Proslogin. The argument by defining God as “something than which nothing greater can be conceived”. God then exists in the understanding since we understand this concept. However, if, He only existed in the understanding something greater could be conceived, for a being that exists in reality is greater than one that exists in the understanding. Bu then, we can conceive of something greater than that than which nothing greater can be conceived, which is contradictory. Therefore, God cannot exist on the understanding, but exists in reality.
An influential argument (or family of arguments) for the existence of God, finding its premisses are that all natural things are dependent for their existence on something else. The totality of dependent brings must then itself depend upon a non-dependent, or necessarily existent bring of which is God. Like the argument to design, the cosmological argument was attacked by the Scottish philosopher and historian David Hume (1711-76) and Immanuel Kant.
Its main problem, nonetheless, is that it requires us to make sense of the notion of necessary existence. For if the answer to the question of why anything exists is that some other tings of a similar kind exists, the question merely arises gain. So the “God” that ends the question must exist necessarily: It must not be an entity of which the same kinds of questions can be raised. The other problem with the argument is attributing concern and care to the deity, not for connecting the necessarily existent being it derives with human values and aspirations.
The ontological argument has been treated by modern theologians such as Barth, following Hegel, not so much as a proof with which to confront the unconverted, but as an explanation of the deep meaning of religious belief. Collingwood, regards the argument s proving not that because our idea of God is that of id quo maius cogitare viequit, therefore God exists, but proving that because this is our idea of God, we stand committed to belief in its existence. Its existence is a metaphysical point or absolute presupposition of certain forms of thought.
In the 20th century, modal versions of the ontological argument have been propounded by the American philosophers Charles Hertshorne, Norman Malcolm, and Alvin Plantinge. One version is to define something as unsurpassably great, if it exists and is perfect in every “possible world”. Then, to allow that it is at least possible that an unsurpassable great being existed. This means that there is a possible world in which such a being exists. However, if it exists in one world, it exists in all (for the fact that such a being exists in a world that entails, in at least, it exists and is perfect in every world), so, it exists necessarily. The correct response to this argument is to disallow the apparently reasonable concession that it is possible that such a being exists. This concession is much more dangerous than it looks, since in the modal logic, involved from possibly necessarily “p”, we can device necessarily “p”. A symmetrical proof starting from the assumption that it is possibly that such a being not exist would derive that it is impossible that it exists.
The doctrine that it makes an ethical difference of whether an agent actively intervenes to bring about a result, or omits to act in circumstances in which it is foreseen, that as a result of the omission the same result occurs. Thus, suppose that I wish you dead. If I act to bring about your death, I am a murderer, however, if I happily discover you in danger of death, and fail to act to save you, I am not acting, and therefore, according to the doctrine of acts and omissions not a murderer. Critics implore that omissions can be as deliberate and immoral as I am responsible for your food and fact to feed you. Only omission is surely a killing, “Doing nothing” can be a way of doing something, or in other worlds, absence of bodily movement can also constitute acting negligently, or deliberately, and defending on the context ,may be a way of deceiving, betraying, or killing. Nonetheless, criminal law offers to find its conveniences, from which to distinguish discontinuous intervention, for which is permissible, from bringing about result, which may not be, if, for instance, the result is death of a patient. The question is whether the difference, if there is one, is, between acting and omitting to act be discernibly or defined in a way that bars a general moral might.
The double effect of a principle attempting to define when an action that had both good and bad results is morally permissible. I one formation such an action is permissible if (1) The action is not wrong in itself, (2) the bad consequences is not that which is intended (3) the good is not itself a result of the bad consequences, and (4) the two consequential effects are commensurate. Thus, for instance, I might justifiably bomb an enemy factory, foreseeing but intending that the death of nearby civilians, whereas bombing the death of nearby civilians intentionally would be disallowed. The principle has its roots in Thomist moral philosophy, accordingly. St. Thomas Aquinas (1225-74), held that it is meaningless to ask whether a human being is two tings (soul and body) or, only just as it is meaningless to ask whether the wax and the shape given to it by the stamp are one: On this analogy the sound is ye form of the body. Life after death is possible only because a form itself doe not perish (pricking is a loss of form).
Within the revolutionary communism, Karl Marx (1818-83) and the German social philosopher Friedrich Engels (1820-95), there emerges a rather different kind of story, based upon Hefl's progressive structure not laying the achievement of the goal of history to a future in which the political condition for freedom comes to exist, so that economic and political fears than “reason” is in the engine room. Although, it is such that speculations upon the history may that it be continued to be written, notably: late examples, by the late 19th century large-scale speculation of tis kind with the nature of historical understanding, and in particular with a comparison between the ,methos of natural science and with the historians. For writers such as the German neo-Kantian Wilhelm Windelband and the German philosopher and literary critic and historian Wilhelm Dilthey, it is important to show that the human sciences such as history is objective and legitimate, nonetheless they are in some way deferent from the enquiry of the scientist. Since the subjective-matter is the past thought and actions of human brings, what is needed and actions of human beings, past thought and actions of human beings, what is needed is an ability to re-live that past thought, knowing the deliberations of past agents, as if they were the historian's own. The most influential British writer on this theme was the philosopher and historian George Collingwood (1889-1943) whose, The Idea of History (1946), contains an extensive defence of the verstehe approach, but it is nonetheless, the explanation from their actions, however, by re-living the situation as our understanding that understanding others is not gained by the tactic use of a “theory”, enabling us to infer what thoughts or intentionality experienced, again, the matter to which the subjective-matters of past thoughts and actions , as I have a human ability of knowing the deliberations of past agents as if they were the historian”s own. The immediate question of the form of historical explanation, and the fact that general laws have other than no place or any apprentices in the order of a minor place in the human sciences, it is also prominent in thoughts about distinctiveness as to regain their actions, but by re-living the situation in or thereby understanding of what they experience and thought.
By Comparison, Bolzano argues, though, that there is something else, an infinity that doe not have this ‘whatever you need it to be’ elasticity. In fact a truly infinite quantity (for example, the length of a straight line unbounded in either direction, meaning: The magnitude of the spatial entity containing all the points determined solely by their abstractly conceivable relation to two fixed points) does not by any means need to be variable, and in adduced example it is in fact not variable. Conversely, it is quite possible for a quantity merely capable of being taken greater than we have already taken it, and of becoming larger than any pre-assigned (finite) quantity, nevertheless to mean at all times merely finite, which holds in particular of every numerical quantity 1, 2, 3, 4, 5.
In other words, for Bolzano there could be a true infinity that was not a variable ‘something’ that was only bigger than anything you might specify. Such a true infinity was the result of joining two pints together and extending that line in both directions without stopping. And what is more, he could separate off the demands of calculus, using a finite quality without ever bothering with the slippery potential infinity. Here was both a deeper understanding of the nature of infinity and the basis on which are built in his ‘safe’ infinity free calculus.
This use of the inexhaustible follows on directly from most Bolzano’s criticism of the way that ∞ we used as a variable something that would be bigger than anything you could specify, but never quite reached the true, absolute infinity. In Paradoxes of the Infinity Bolzano points out that is possible for a quantity merely capable of becoming larger than any one pre-assigned (finite) quantity, nevertheless to remain at all times merely finite.
Bolzano intended tis as a criticism of the way infinity was treated, but Professor Jacquette sees it instead of a way of masking use of practical applications like calculus without the need for weasel words about infinity.
By replacing ∞ with ¤ we do away with one of the most common requirements for infinity, but is there anything left that map out to the real world? Can we confine infinity to that pure mathematical other world, where anything, however unreal, can be constructed, and forget about it elsewhere? Surprisingly, this seems to have been the view, at least at one point in time, even of the German mathematician and founder of set-theory Georg Cantor (1845-1918), himself, whose comments in 1883, that only the finite numbers are real.
Keeping within the lines of reason, both the Cambridge mathematician and philosopher Frank Plumpton Ramsey (1903-30) and the Italian mathematician G. Peano (1858-1932) have been to distinguish logical paradoxes and that depend upon the notion of reference or truth (semantic notions), such are the postulates justifying mathematical induction. It ensures that a numerical series is closed, in the sense that nothing but zero and its successors can be numbers. In that any series satisfying a set of axioms can be conceived as the sequence of natural numbers. Candidates from set theory include the Zermelo numbers, where the empty set is zero, and the successor of each number is its unit set, and the von Neuman numbers, where each number is the set of all smaller numbers. A similar and equally fundamental complementarity exists in the relation between zero and infinity. Although the fullness of infinity is logically antithetical to the emptiness of zero, infinity can be obtained from zero with a simple mathematical operation. The division of many numbers by zero is infinity, while the multiplication of any number by zero is zero.
With the set theory developed by the German mathematician and logician Georg Cantor. From 1878 to 1807, Cantor created a theory of abstract sets of entities that eventually became a mathematical discipline. A set, as he defined it, is a collection of definite and distinguished objects in thought or perception conceived as a whole.
Cantor attempted to prove that the process of counting and the definition of integers could be placed on a solid mathematical foundation. His method was to repeatedly place the elements in one set into ‘one-to-one’ correspondence with those in another. In the case of integers, Cantor showed that each integer (1, 2, 3, . . . n) could be paired with an even integer (2, 4, 6, . . . n), and, therefore, that the set of all integers was equal to the set of all even numbers.
Amazingly, Cantor discovered that some infinite sets were large than others and that infinite sets formed a hierarchy of greater infinities. After this failed attempt to save the classical view of logical foundations and internal consistency of mathematical systems, it soon became obvious that a major crack had appeared in the seemingly sold foundations of number and mathematics. Meanwhile, an impressive number of mathematicians began to see that everything from functional analysis to the theory of real numbers depended on the problematic character of number itself.
While, in the theory of probability Ramsey was the first to show how a personalised theory could be developed, based on precise behavioural notions of preference and expectation. In the philosophy of language, Ramsey was one of the first thinkers to accept a ‘redundancy theory of truth’, which hr combined with radical views of the function of man y kinds of propositions. Neither generalizations nor causal propositions, nor those treating probability or ethics, describe facts, but each has a different specific function in our intellectual economy.
Ramsey advocates that of a sentence generated by taking all the sentence affirmed in a scientific theory that use some term, e.g., ‘quark’. Replacing the term by a variable, and existentially quantifying into the result. Instead of saying quarks have such-and-such properties, Ramsey postdated that the sentence as saying that there is something that has those properties. If the process is repeated, the sentence gives the ‘topic-neutral’ structure of the theory, but removes any implications that we know what the term so treated denote. I t leaves open the possibility of identifying the theoretical item with whatever it is that best fits the description provided. Nonetheless, it was pointed out by the Cambridge mathematician Newman that if the process is carried out for all except the logical bones of the theory, then by the Löwenheim-Skolem theorem, the result will be interpretable in any domain of sufficient cardinality, and the content of the theory may reasonably be felt to have been lost.
It seems, that the most taken of paradoxes in the foundations of ‘set theory’ as discovered by Russell in 1901. Some classes have themselves as members: The class of all abstract objects, for example, is an abstract object, whereby, others do not: The class of donkeys is not itself a donkey. Now consider the class of all classes that are not members of themselves, is this class a member of itself, that, if it is, then it is not, and if it is not, then it is.
The paradox is structurally similar to easier examples, such as the paradox of the barber. Such one like a village having a barber in it, who shaves all and only the people who do not have in themselves. Who shaves the barber? If he shaves himself, then he does not, but if he does not shave himself, then he does not. The paradox is actually just a proof that there is no such barber or in other words, that the condition is inconsistent. All the same, it is no to easy to say why there is no such class as the one Russell defines. It seems that there must be some restriction on the kind of definition that are allowed to define classes and the difficulty that of finding a well-motivated principle behind any such restriction.
The French mathematician and philosopher Henri Jules Poincaré (1854-1912) believed that paradoses like those of Russell nd the ‘barber’ were due to such as the impredicative definitions, and therefore proposed banning them. But, it tuns out that classical mathematics required such definitions at too many points for the ban to be easily absolved. Having, in turn, as forwarded by Poincaré and Russell, was that in order to solve the logical and semantic paradoxes it would have to ban any collection (set) containing members that can only be defined by means of the collection taken as a whole. It is, effectively by all occurring principles into which have an adopting vicious regress, as to mark the definition for which involves no such failure. There is frequently room for dispute about whether regresses are benign or vicious, since the issue will hinge on whether it is necessary to reapply the procedure. The cosmological argument is an attempt to find a stopping point for what is otherwise seen as being an infinite regress, and, to ban of the predicative definitions.
The investigation of questions that arise from reflection upon sciences and scientific inquiry, are such as called of a philosophy of science. Such questions include, what distinctions in the methods of science? s there a clear demarcation between scenes and other disciplines, and how do we place such enquires as history, economics or sociology? And scientific theories probable or more in the nature of provisional conjecture? Can the be verified or falsified? What distinguished good from bad explanations? Might there be one unified since, embracing all th special science? For much of the 20th century there questions were pursued in a highly abstract and logical framework it being supposed that as general logic of scientific discovery that a general logic of scientific discovery a justification might be found. However, many now take interests in a more historical, contextual and sometimes sociological approach, in which the methods and successes of a science at a particular time are regarded less in terms of universal logical principles and procedure, and more in terms of their availability to methods and paradigms as well as the social context.
In addition, to general questions of methodology, there are specific problems within particular sciences, giving subjects as biology, mathematics and physics.
The intuitive certainty that sparks aflame the dialectic awarenesses for its immediate concerns are either of the truth or by some other in an object of apprehensions, such as a concept. Awareness as such, has to its amounting quality value the place where philosophical understanding of the source of our knowledge are, however, in covering the sensible apprehension of things and pure intuition it is that which stricture sensation into the experience of things accent of its direction that orchestrates the celestial overture into measures in space and time.
The notion that determines how something is seen or evaluated of the status of law and morality especially associated with St Thomas Aquinas and the subsequent scholastic tradition. More widely, any attempt to cement the moral and legal order together with the nature of the cosmos or how the nature of human beings, for which sense it is also found in some Protestant writers, and arguably derivative from a Platonic view of ethics, and is implicit in ancient Stoicism. Law stands above and apart from the activities of human lawmaker, it constitutes an objective set of principles that can be seen true by ‘natural light’ or reason, and (in religion versions of the theory) that express God’s will for creation. Non-religious versions of the theory substitute objective conditions for human flourishing as the source of constraints upon permissible actions and social arrangements. Within the natural law tradition, different views have been held about the relationship between the rule of law about God’ s will, for instance the Dutch philosopher Hugo Grothius (1583-1645), similarly takes upon the view that the content of natural law is independent of any will, including that of God, while the German theorist and historian Samuel von Pufendorf (1632-94) takes the opposite view, thereby facing the problem of one horn of the Euthyphro dilemma, that simply states, that its dilemma arises from whatever the source of authority is supposed to be, for in which do we care about the general good because it is good, or do we just call good things that we care about. Wherefore, by facing the problem that may be to assume of a strong form, in which it is claimed that various facts entail values, or a weaker form, from which it confines itself to holding that reason by itself is capable of discerning moral requirements that are supped of binding to all human bings regardless of their desires
Although the morality of people send the ethical amount from which the same thing, is that there is a usage that restricts morality to systems such as that of the German philosopher and founder of ethical philosophy Immanuel Kant (1724-1804), based on notions such as duty, obligation, and principles of conduct, reserving ethics for more than the Aristotelian approach to practical reasoning based on the notion of a virtue, and generally avoiding the separation of ‘moral’ considerations from other practical considerations. The scholarly issues are complex, with some writers seeing Kant as more Aristotelian and Aristotle as, ore involved in a separate sphere of responsibility and duty, than the simple contrast suggests. Some theorists see the subject in terms of a number of laws (as in the Ten Commandments). The status of these laws may be test they are the edicts of a divine lawmaker, or that they are truths of reason, knowable deductively. Other approaches to ethics (e.g., eudaimonism, situation ethics, virtue ethics) eschew general principles as much as possible, frequently disguising the great complexity of practical reasoning. For Kantian notion of the moral law is a binding requirement of the categorical imperative, and to understand whether they are equivalent at some deep level. Kant’s own applications of the notion are not always convincing, as for one cause of confusion in relating Kant’s ethics to theories such additional expressivism is that it is easy, but mistaken, to suppose that the categorical nature of the imperative means that it cannot be the expression of sentiment, but must derive from something ‘unconditional’ or ‘necessary’ such as the voice of reason.
For which ever reason, the mortal being makes of its presence to the future of weighing of that which one must do, or that which can be required of one. The term carries implications of that which is owed (due) to other people, or perhaps in onself. Universal duties would be owed to persons (or sentient beings) as such, whereas special duty in virtue of specific relations, such as being the child of someone, or having made someone a promise. Duty or obligation is the primary concept of ‘deontological’ approaches to ethics, but is constructed in other systems out of other notions. In the system of Kant, a perfect duty is one that must be performed whatever the circumstances: Imperfect duties may have to give way to the more stringent ones. In another way, perfect duties are those that are correlative with the right to others, imperfect duties are not. Problems with the concept include the ways in which due needs to be specified (a frequent criticism of Kant is that his notion of duty is too abstract). The concept may also suggest of a regimented view of ethical life in which we are all forced conscripts in a kind of moral army, and may encourage an individualistic and antagonistic view of social relations.
The most generally accepted account of externalism and/or internalism, that this distinction is that a theory of justification is internalist if only if it requiem that all of the factors needed for a belief to be epistemologically justified for a given person be cognitively accessible to that person, internal to his cognitive percreptive, and externalist, if it allows that at least some of the justifying factors need not be thus accessible, so that thy can be external to the believer’s cognitive perceptive, beyond any such given relations. However, epistemologists often use the distinction between internalist and externalist theories of epistemic justification without offering any very explicit explication.
The externalist/internalist distinction has been mainly applied to theories of epistemic justification: It has also been applied in a closely related way to accounts of knowledge and in a rather different way to accounts of belief and thought contents.
The internalist requirement of cognitive accessibility can be interpreted in at least two ways: A strong version of internalism would require that the believer actually be aware of the justifying factor in order to be justified: While a weaker version would require only that he be capable of becoming aware of them by focussing his attentions appropriately, but without the need for any change of position, new information, etc. Though the phrase ‘cognitively accessible’ suggests the weak interpretion, the main intuitive motivation for internalism, viz the idea that epistemic justification requires that the believer actually have in his cognitive possession a reason for thinking that the belief is true, and would require the strong interpretation.
Perhaps, the clearest example of an internalist position would be a Foundationalist view according to which foundational beliefs pertain to immediately experienced states of mind and other beliefs are justified by standing in cognitively accessible logical or inferential relations to such foundational beliefs. Such a view could count as either a strong or a weak version of internalism, depending on whether actual awareness of the justifying elements or only the capacity to become aware of them is required. Similarly, a coherent view could also be internalist, if both the beliefs or other states with which a justification belief is required to cohere and the coherence relations themselves are reflectively accessible.
It should be carefully noticed that when internalism is construed in this way, it is neither necessary nor sufficient by itself for internalism that the justifying factors literally be internal mental states of the person in question. Not necessary, necessary, because on at least some views, e.g., a direct realist view of perception, something other than a mental state of the believer can be cognitively accessible: Not sufficient, because there are views according to which at least some mental states need not be actual (strong version) or even possible (weak version) objects of cognitive awareness. Also, on this way of drawing the distinction, a hybrid view, according to which some of the factors required for justification must be cognitively accessible while others need not and in general will not be, would count as an externalist view. Obviously too, a view that was externalist in relation to a strong version of internalism (by not requiring that the believer actually be aware of all justifying factors) could still be internalist in relation to a weak version (by requiring that he at least be capable of becoming aware of them).
The most prominent recent externalist views have been versions of reliabilism, whose requirements for justification is roughly that the belief be produced in a way or via a process that makes of objectively likely that the belief is true. What makes such a view externalist is the absence of any requirement that the person for whom the belief is justified have any sort of cognitive access to the relations of reliability in question. Lacking such access, such a person will in general have no reason for thinking that the belief is true or likely to be true , but will, on such an account, nonetheless be epistemically justified in according it. Thus such a view arguably marks a major break from the modern epistemological tradition, stemming from Descartes, which identifies epistemic justification with having a reason, perhaps even a conclusive reason for thinking that the belief is true. An epistemologist working within this tradition is likely to feel that the externalist, than offering a competing account of the same concept of epistemic justification with which the traditional epistemologist is concerned, has simply changed the subject.
The main objection to externalism rests on the intuitive certainty that the basic requirement for epistemic justification is that the acceptance of the belief in question be rational or responsible in relation to the cognitive goal of truth, which seems to require in turn that the believer actually be dialectally aware of a reason for thinking that the belief is true (or, at the very least, that such a reason be available to him). Since the satisfaction of an externalist condition is neither necessary nor sufficient for the existence of such a cognitively accessible reason, it is argued, externalism is mistaken as an account of epistemic justification. This general point has been elaborated by appeal to two sorts of putative intuitive counter-examples to externalism. The first of these challenges the necessity of belief which seem intuitively to be justified, but for which the externalist conditions are not satisfied. The standard examples in this sort are cases where beliefs are produced in some very nonstandard way, e.g., by a Cartesian demon, but nonetheless, in such a way that the subjective experience of the believer is indistinguishable from that of someone whose beliefs are produced more normally. The intuitive claim is that the believer in such a case is nonetheless epistemically justified, as much so as one whose belief is produced in a more normal way, and hence that externalist account of justification must be mistaken.
Perhaps the most striking reply to this sort of counter-example, on behalf of a cognitive process is to be assessed in ‘normal’ possible worlds, i.e., in possible worlds that are actually the way our world is common-seismically believed to be, than in the world which contains the belief being judged. Since the cognitive processes employed in the Cartesian demon cases are, for which we may assume, reliable when assessed in this way, the reliabilist can agree that such beliefs are justified. The obvious, to a considerable degree of bringing out the issue of whether it is or not an adequate rationale for this construal of reliabilism, so that the reply is not merely a notional presupposition guised as having representation.
The correlative way of elaborating on the general objection to justificatory externalism challenges the sufficiency of the various externalist conditions by citing cases where those conditions are satisfied, but where the believers in question seem intuitively not to be justified. In this context, the most widely discussed examples have to do with possible occult cognitive capacities, like clairvoyance. Considering the point in application once, again, to reliabilism, the claim is that to think that he has such a cognitive power, and, perhaps, even good reasons to the contrary, is not rational or responsible and therefore not epistemically justified in accepting the belief that result from his clairvoyance, despite the fact that the reliablist condition is satisfied.
One sort of response to this latter sorts of objection is to ‘bite the bullet’ and insist that such believers are in fact justified, dismissing the seeming intuitions to the contrary as latent internalist prejudice. A more widely adopted response attempts to impose additional conditions, usually of a roughly internalist sort, which will rule out the offending example, while stopping far of a full internalism. But, while there is little doubt that such modified versions of externalism can handle particular cases, as well enough to avoid clear intuitive implausibility, the usually problematic cases that they cannot handle, and also whether there is and clear motivation for the additional requirements other than the general internalist view of justification that externalist are committed to reject.
A view in this same general vein, one that might be described as a hybrid of internalism and externalism holds that epistemic justification requires that there is a justicatory factor that is cognitively accessible to the believer in question (though it need not be actually grasped), thus ruling out, e.g., a pure reliabilism. At the same time, however, though it must be objectively true that beliefs for which such a factor is available are likely to be true, in addition, the fact need not be in any way grasped or cognitively accessible to the believer. In effect, of the premises needed to argue that a particular belief is likely to be true, one must be accessible in a way that would satisfy at least weak internalism, the internalist will respond that this hybrid view is of no help at all in meeting the objection and has no belief nor is it held in the rational, responsible way that justification intuitively seems to require, for the believer in question, lacking one crucial premise, still has no reason at all for thinking that his belief is likely to be true.
An alternative to giving an externalist account of epistemic justification, one which may be more defensible while still accommodating many of the same motivating concerns, is to give an externalist account of knowledge directly, without relying on an intermediate account of justification. Such a view will obviously have to reject the justified true belief account of knowledge, holding instead that knowledge is true belief which satisfies the chosen externalist condition, e.g., a result of a reliable process (and perhaps, further conditions as well). This makes it possible for such a view to retain internalist account of epistemic justification, though the centrality of that concept to epistemology would obviously be seriously diminished.
Such an externalist account of knowledge can accommodate the commonsense conviction that animals, young children, and unsophisticated adults posses knowledge, though not the weaker conviction (if such a conviction does exists) that such individuals are epistemically justified in their beliefs. It is also at least less vulnerable to internalist counter-examples of the sort discussed, since the intuitions involved there pertain more clearly to justification than to knowledge. What is uncertain is what ultimate philosophical significance the resulting conception of knowledge is supposed to have. In particular, does it have any serious bearing on traditional epistemological problems and on the deepest and most troubling versions of scepticism, which seems in fact to be primarily concerned with justification, th an knowledge?`
A rather different use of the terms ‘internalism’ and ‘externalism’ has to do with the issue of how the content of beliefs and thoughts is determined: According to an internalist view of content, the content of such intention states depends only on the non-relational, internal properties of the individual’s mind or grain, and not at all on his physical and social environment: While according to an externalist view, content is significantly affected by such external factors and suggests a view that appears of both internal and external elements is standardly classified as an external view.
As with justification and knowledge, the traditional view of content has been strongly internalist in character. The main argument for externalism derives from the philosophy y of language, more specifically from the various phenomena pertaining to natural kind terms, indexicals, etc. that motivate the views that have come to be known as ‘direct reference’ theories. Such phenomena seem at least to show that the belief or thought content that can be properly attributed to a person is dependant on facts about his environment-e.g., whether he is on Earth or Twin Earth, what is fact pointing at, the classificatory criteria employed by expects in his social group, etc.-not just on what is going on internally in his mind or brain.
An objection to externalist account of content is that they seem unable to do justice to our ability to know the content of our beliefs or thought ‘from the inside’, simply by reflection. If content is depend on external factors pertaining to the environment, then knowledge of content should depend on knowledge of these factors-which will not in general be available to the person whose belief or thought is in question.
The adoption of an externalist account of mental content would seem to support an externalist account of justification, by way that if part or all of the content of a belief inaccessible to the believer, then both the justifying status of other beliefs in relation to that content and the status of that content ss justifying further beliefs will be similarly inaccessible, thus contravening the internalist requirement for justification. An internalist must insist that there are no justification relations of these sorts, that our internally associable content can either be justified or justly anything else: But such a response appears lame unless it is coupled with an attempt to show that the externalist account of content is mistaken.
EVOLVING PRINCIPLES OF THOUGHT
Richard j.Kosciejew
A BRIEFING
Mysteriousness, is the source of all possible science, that through or upon its participation or observation we are met with direct and added operations and processes carried out to resolve an uncertainty. As a matter-of-course, the theory of knowledge as so distinguished from two or more inferred diversifiers, if upon which its central questions include, the origin of knowledge, the place of experience in generating knowledge, and the place of reason in doing so. The relationship between knowledge and certainty, and between knowledge and the impossibility of error, the possibility of universal ‘scepticism’ and the changing forms of knowledge that arise from new conceptualizations of the world. All these issues link with other central concerns of philosophy, such as the nature of truth and the nature of experience and meaning. Seeing epistemology is possible as dominated by two rival metaphors. One is that of a building or pyramid, built on foundations. In this conception it is the job of the philosopher to describe especially secure foundations, and to identify secure modes of construction, so that the resulting edifice can be shown to be sound.
This metaphor, of a special privilege favour to what in the mind as a representation, as of something comprehended or, as a formulation, or a plan that has characteristic distinction, when added up to some idea that ‘given’ to issue is an effectively basic idea or the principal object of our attention in a discourse or composite explication and embarks upon its topic, as to the ‘be-all’ and ‘end-all’ of justifiable knowledge. Continuing to have attached on or upon a connection especially logical, as this situation bears directly upon the capabilities, for being to enable the clarifications to keep a rationally derivable theory upon which confirmation and inferences are feasible methods of constitution. The view in epistemology that knowledge must be regarded as a structure raised upon secure, certain foundations. These are found in some combination of experiences and reason, with different schools (‘empiricism’, ‘rationalism’) emphasizing the role of one over the other. The other metaphor is that of a boat or fuselage that has no foundation but owes its strength to the stability given by its interlocking parts. This rejects the idea of a basis in the given, and favours ideas of ‘coherence’ and ‘holism’, but finds it harder to ward off scepticism.
The problem of defining knowledge as for true belief plus some favoured relation between the believer and that which began with Plato’s view in the Theaetetus that knowledge is true belief plus a logo.
The preference for reason to sense experience as a source of knowledge began with the Eleatics, and played a central role in Platonism. Its most significant modern development was in the 17th century belief that the paradigm of knowledge was the non-sensory intellectual intuition that God would have put into working of all things, and the human being’s task in their acquaintance with mathematics. The Continental rationalists, notably Descartes, Leibniz and Spinoza are frequently contrasted with the British empiricists Locke, Berkeley and Hume, but each opposition is usually an over-simplicity of more complex pictures, for example, it is worth noticing the extent to which Descartes approves of empirical equity, and the extent to which Locke shared the rationalist vision of real knowledge as a kind of intellectual intuition.
In spite of the confirmable certainty of Kant, the subsequent history of philosophy has unstretchingly decreased in amounts to lessen of such things as having to reduce the distinction between experience and thought. Even to deny the possibility of ‘deductive knowledge’ so rationalism depending on this category has also declined. However, the idea that the mind comes with pre-formed categories that determine the structure of language and the ways of thought has survived in the works of linguistics influenced by Chomsky. The term rationalism is also more broadly for any anti-clerical anti-authoritarian humanism, but empiricists such as the Scottish philosopher and essayist David Hume (1711-76), who sides with other relativistic senses.
A fully formalized confirmation theory would dictate the confidence that a rational investigator might have in a theory, given to some indication of evidence. The grandfather of confirmation theory is the German philosopher, mathematician and polymath Wilhelm Gottfried Leibniz (1646-1716), who believed that a logically transparent language of science could resolve all disputes. In the 20th century as fully formal confirmation theory was a main goal of the ‘logical positivists’, since without if the central concept of verification empirical evidence itself remains distressingly unscientific. The principal developments were due to the German logical positivist Rudolf Carnap (1891-1970), culminating in his “Logical Foundations of Probability” (1950). Carnap’s idea was that the meaning necessary for which purposes would considerably carry the first act or step of an action of operations having actuality or reality for being directly the proportion of logical possible states of affairs. In which having or manifesting the concerning abstraction and theory, under which, the indications confirming the pronounced evidences that comparatively such are by, comparison, an expressed or implied standard, or absolute number, from which the essential or conditional confirmation, for which the manifesting affirmation was to evince the relevant significance for it, the progressive uncovering held by reserving the act or manner of grasping or holding on the sides of approval.
All the same, the ‘range theory of probability’ holds that the probability of a proposition compared with some evidence, is a preposition of the range of possibilities under which the proposition is true, compared to the total range of possibilities left open by the evidence. The theory was originally due to the French mathematician Simon Pierre LaPlace (1749-1827), and has guided confirmation theory, for example in the work of the German local positivist, Rudolf Carnap (1891-1970). The difficulty with the theory lies in identifying sets of possibilities so that they admit of measurement, LaPlace appealed to the principle of ‘difference’ supporting that possibilities have an equal probability that would otherwise move another to do or agree to come into being, is that, the particular effectuality of representative characterlogical informality, with which is understood to make out as or perceivable vision. Still, something as known in regard to the given possibility of a strong decision, as this amendable appraisal of resulting capabilities is to keep in a state of efficiency or premises the idea of proceeding a proceeding matter of fact. In that what is generally of something made or to make or produce as in quality or value. The parallel status or effectual amounts to the same thing in accord are equally measured in the different distinctions as regularly objective-equally that if you can, the choice of mischance or alternatively a reason for distinguishing them. However, unrestricted appeal to this principle introduces inconsistency as equally probable regard as depending upon metaphysical choices, as inferred in his work on the logical choices, as in the regarding work of Carnap.
In any event finding an objective source for authority of such a choice is hard, and this is a principal difficulty in front of formalizing the theory of confirmation.
It therefore demands that we can put to measure in the ‘range’ of possibilities consistent with theory and evidence, compared with the range consistent with the evidence alone. Among the following set arrangements, or pattern the methodic orderliness, a common description of estranged dissimulations occurring a sudden beginning of activity as marked from the traditional or usual moderation of obstructing obstacles that seriously hampers actions or the propagation for progress. In fact, a condition or occurrence traceable to cause to induce of one to come into being, specifically to carry to a successful conclusion to come or go, into some place or thing of a condition of being deeply involved or closely linked, often in a compromising way that as much as it is needed or wanting for all our needs, however, the enterprising activities gainfully energize interests to attempt or engage in what requires of readiness or daring ambition for showing an initiative toward resolutions, and, yet, by determining effort to tower far and above. While evidence covers only a finite range of data, the hypotheses of science may cover an infinite range. In addition, confirmation proved to vary with the language in which the science is couched, and the Carnapian programme has difficulty in separating genuinely confirming variety of evidence from less compelling recitation of the same experiments, confirmation also was susceptible to acute paradoxes.
Such that the classical problem of ‘induction’ is phrased as finding some reason to expect that nature is uniform: In “Fact, Fiction, and Forecast” (1954), Nelson Goodman, an American philosopher (1906-98), showed that we need, in addition some reason for preferring some uniformities to others, for without such a selection the uniformity of nature is vacuous. Thus, suppose that all examined emeralds have been green. Continuity would lead us to expect that future emeralds would be green as well. Suspenseful distinctions are now descriptive statements on or upon that we define the predicated stuff: ‘x’ as stuff, if we retrospectively view of or meditation on past events if they put ‘x’ to the question, the sampling representations catechize a query as examined before uncoming for the reasons present of time ‘T’ and, so in fact, things are not always the way they are seen, nonetheless, charactering ‘T’ or ‘x’ is examined after to resemble or follow, as to reason or control through some various inclination of being, occurring, or carried out at a time after something else, as ‘T’ and just as stated, contributed the condition of being expressed to something with which happened without variations from a course or procedure or from a norm or standard, no deviation from traditional methods. Consequently, the eventual inevitability happens to take place or come about as its resultant amount qualifies to be blue, letting ‘T’ submit to some time around the course as now existing or in progress, for which the present state concurs to ventilate the apprehensive present. Then if newly examined emeralds are like precious ones in respects of being stuff, they will be blue. We prefer blueness as a basis of prediction to stuff-ness, but why? Rather than retreating to realism, Goodman pushes in the opposite direction to what he calls, ‘irrealism’, holding that each version (each theoretical account of reality) produces a new world. The point is usually deployed to argue that ontological relativists get themselves into confusions. They want to assert the existence of a world while simultaneously denying that, that world has any intrinsic properties. The ontological relativist wants to deny the meaningfulness of postulating intrinsic properties of the world, as a position assumed or a point made especially in controversy, that if in the act or process of thinking, as to be at rest immersed in deep thought, provided to some conventional mannerism that no one has theoretically shaped or given to its shapeful symmetric balance in some sense. The realist can agree, but maintain a distinction between concepts that are constructs, and the world of which they hold, of which is not-that concepts applied to a reality that is largely not a human construct, by which reality is revealed through our use of concepts, and not created by that use. Howe’er, the basic response of the relativist is to question of what seems as the concepts of mind and world with the pre-critical insouciance required to defend the realist position. The worry of the relativist is that we cannot. The most basic concepts used to set up our ontological investigations have complex histories and interrelationships with other concepts. Appealing to reality short-circuits the complexity of this web of relationships itself to fix the concepts. What remains clear is that the possibility of these ‘bent’ predicates puts a deceptive obstacle in the face of purely logical and syntactical approaches to problems of ‘confirmation’.
Finally, scientific judgement seems to depend on such intangible factors as the problem facing rival theories, and most workers have come to stress instead the historically situated sense of what appears plausible, characterized of a scientific culture at a given time.
Even so, the principle central to ‘logical positivism’, according to which the meaning of a statement is its method of verification. Sentences apparently expressing propositions that admit to no verification (such as those of metaphysics and theology) that are significantly meaningless, or at least, fail to put forward theses with cognitive meanings, with the importance in the capabilities of truth or falsity. The principle requires confidence that we know what a verification consists in, and served to co-exist with a simple conception of each thought as answerable to individual experience. To bypass undue simplicity is to maintain the unaffected actualities or apparent deficient ease of intelligence of sense of common purpose or a degree of dedication to a common task regarded as characteristic of a set of emotional gains founded by its restorative corrections, which, in turn for conquest or plunder the same requiring condition justly makes the reallocating position from an acquiring strong or conducive verification. That intending through which points of admitting deprivation, is only to prove of the totality for which is inadequately inconclusive, in that of a means or procedure used in attaining a result method for verification. Nonetheless, more complex and holistic concepts of language and its relationship to the world suggest a more flexible set of possible relations, with sentences that are individually not verifiable, nevertheless having a use in an overall network of beliefs or theory that it answers to experience, and explanation.
Being such beyond doubt, issues surrounding certainty are inextricably connected with those concerning ‘scepticism’. For many sceptics have traditionally held that knowledge requires certainty, and, of course, they claim that specific knowledge is not-possible. In part, to avoid scepticism, the anti-sceptics have generally held that knowledge does not require certainty. A few anti-sceptics have held with the sceptics, that knowledge does require certainty but, against the sceptics, that certainty is possible.
Clearly, certainty is intuitively a property that can be ascribed to either a person or a belief. We can say that a person ‘S’, conscionably to be all or a fundamental part of the substance that contractually affect to induce to come into being its defining certainty, or we can say that a proposition ’p’, must also be intuitively certain. Much that to availing the serviceable combinations for saying that ‘S’ has the right to be certain just in case they sufficiently warrant ‘p’.
There is no basis in contemporary physics or biology for believing in the stark Cartesian division between mind and world that some have moderately described as ‘the disease of the Western mind’, Descartes, quickly realized that there was nothing in the view of nature that could explain or provide a foundation for the mental, or for all that we know from direct or experience as distinctly relating to, or characteristic of mankind, the hominid, which is a member of the human race. In a mechanistic universe, there is made of comment, there is no privileged place for uncertainty for mind, and the separation between mind and matter is absolute. Descartes was also convinced, however, that the immaterial essences that gave form and structure to this universe were coded in geometrical and mathematical ideas, and this insight led him to invent algebraic geometry. However, in Nietzsche’s view, the separation between mind and matter is more absolute than had previously been imagined. Based on the assumptions that there are no real or necessary correspondences between linguistic constructions of reality in human subjectivity and external reality, he declared that we are all of a space that the philosopher can examine the ‘innermost desires of his nature’ and articulate a new message of individual existence founded on ‘will’
Nietzsche’s emotionally charged defence of intellectual freedom and his radical empowerment of mind as the maker and transformer of the collective fictions that shape human reality in a soulless mechanistic universe proved terribly non-influential one twentieth-century thought. Nietzsche sought to reenforce his view of the subjective character of scientific knowledge by appealing to an epistemological crisis over the foundations of logic and arithmetic that arose during the last three decades of the nineteenth century, though a curious course of events, attempted by Edmund Husserl, a philosopher trained in higher math and physics, to resolve this crisis resulted in a view of the character of human consciousness that closely resembled that of Nietzsche.
Not to exclude, that the cumulation progress of science imposes constraints on what can be viewed as a legitimate scientific concept, problem, of the hypothesis, and that their constraints become tighter as science progresses, this, however, is particularly so when the results of theory present us with radically new and seemingly contributive findings like the results of experiments on non-locality. It is because there is incessant feedback within the content and conduct of science that we are led to such counterintuitive results.
Dialectic orchestration will serve as the background for understanding a new relationship between parts and wholes in physics, with a similar view of that relationship that has emerged in the co-called ‘new biology’ and in recent studies of the evolution of a scientific understanding to a more conceptualized representation of ideas, and includes its allied ‘content’.
Nonetheless, it seems a strong possibility that Plotonic and Whitehead connect upon the issue of the creation of the sensible world may by looking at actual entities as aspects of nature’s contemplation. The contemplation of nature is obviously an immensely intricate affair, involving a myriad of possibilities, therefore one can look at actual entities as, in some sense, the basic elements of a vast and expansive process.
We could derive a scientific understanding of these ideas with the aid of precise deduction, as Descartes continued his claim that we could lay the contours of physical reality out in three-dimensional co-ordinates. Following the publication of Isaac Newton’s “Principia Mathematica” in 1687, reductionism and mathematical modeling became the most powerful tools of modern science. The dream that we could know and master the entire physical world through the extension and refinement of mathematical theory became the central feature and principals of scientific knowledge.
The radical separation between mind and nature formalized by Descartes served over time to allow scientists to concentrate on developing mathematical descriptions of matter as pure mechanism without any concern about its spiritual dimensions or ontological foundations. Meanwhile, attempts to rationalize, reconcile or eliminate Descartes’s merging division between mind and matter became the most central feature of Western intellectual life.
Philosophers like John Locke, Thomas Hobbes, and David Hume tried to articulate some basis for linking the mathematical describable motions of matter with linguistic representations of external reality in the subjective space of mind. Descartes’ compatriot Jean-Jacques Rousseau reified nature as the ground of human consciousness in a state of innocence and proclaimed that ‘Liberty, Equality, Fraternities’ are the guiding principles of this consciousness. Rousseau also fabricated the idea of the ‘general will’ of the people to achieve these goals and declared that those who do not conform to this will were social deviants.
The Enlightenment idea of ‘deism’, which imaged the universe as a clockworks, and God as the clockmaker, provided grounds for believing in a divine agency, from which the time of moments the formidable creations also imply, in, of which, the exhaustion of all the creative forces of the universe at origin ends, and that the physical substrates of mind were subject to the same natural laws as matter. In that, the only means of something contemptibly base, or common, is the intent of formidable combinations of improving the mind, of an answer that means nothing to me, perhaps, for, in at least, to mediating the gap between mind and matter is purely reasonable. Causal implications bearing upon the matter in hand resume or take again the measure to return to or begin again after some interruptive activities such that by taking forwards and accepting a primarily displacing restoration to life. Wherefore, its placing by orienting a position as placed on the table for our considerations, we approach of what is needed to find of unexpected worth or merit obtained or encountered more or less by chance and discover ourselves of an implicit processes and instance of separating or of being separated. That is, of not only in equal parts from that which limits or qualifies by even variations or fluctuation, that occasion disunity, is a continuity for which it is said by putting or bringing back, an existence or use thereof. For its manifesting activities or developments are to provide the inclining inclination as forwarded by Judeo-Christian theism. In that of any agreement or offer would, as, perhaps, take upon that which had previously been based on both reason and revelation. Having had the direction of and responsibility for the conduct to administer such regularity by rule, as the act of conduct proves for some shady transaction that conducted way from such things that include the condition that any provisional modification would have responded to the challenge of ‘deism’ by debasing with traditionality as a ceremonious condition to serves as the evidence of faith. Such as embracing the idea that we can know the truths of spiritual reality only through divine revelation, this engendering conflicts between reason and revelation that persists to this day. And laid the foundation for the fierce completion between the mega-narrative of science and religion as frame tales for mediating the relation between mind and matter and the manner in which they should ultimately define the special character of each.
The nineteenth-century Romantics in Germany, England and the United States revived Rousseau’s attempt to posit a ground for human consciousness by reifying nature in a different form. The German man of letters, J.W.Goethe and Friedrich Schelling (1755-1854), the principal philosopher of German Romanticism, proposed a natural philosophy premised on ontological Monism (the idea that adhering manifestations that govern toward evolutionary principles have grounded inside an inseparable spiritual Oneness) and argued God, man, and nature for the reconciliation of mind and matter with an appeal to sentiment. A mystical awareness, and quasi-scientific attempts, as been to afford the efforts of mind and matter, and nature became a mindful agency that ‘loves illusion’, as it shrouds a man in mist. Therefore, presses him or her heart and punishes those who fail to see the light, least of mention, the principal philosopher, German Romanticist E.W.J. Schelling, in his version of cosmic unity, argued that scientific facts were at best, partial truths and that the creatively minded spirit that unities mind and matter is progressively moving toward ‘self-realization’ and ‘undivided wholeness’.
The British version of Romanticism, articulated by figures like William Wordsworth and Samuel Taylor Coleridge, placed more emphasis on the primary of the imagination and the importance of rebellion and heroic vision as the grounds for freedom. As Wordsworth put it, communion with the ‘incommunicable powers’ of the ‘immortal sea’ empowers the mind to release itself from all the material constraints of the laws of nature. The founders of American transcendentalism, Ralph Waldo Emerson and Henry David Theoreau, articulated a version of Romanticism that commensurate with the ideals of American democracy.
The Americans envisioned a unified spiritual reality that manifested itself as a personal ethos that sanctioned radical individualism and bred aversion to the emergent materialism of the Jacksonian era. They were also more inclined than their European counterpart, as the examples of Thoreau and Whitman attest, to embrace scientific descriptions of nature. However, the Americans also dissolved the distinction between mind and matter with an appeal to ontological monism and alleged that mind could free itself from all the constraint of assuming that by some sorted limitation of matter, in which such states have of them, some mystical awareness.
Since scientists, during the nineteenth century were engrossed with uncovering the workings of external reality and seemingly knew of themselves that these virtually overflowing burdens of nothing, in that were about the physical substrates of human consciousness, the business of examining the distributive contribution in dynamic functionality and structural foundation of mind became the province of social scientists and humanists. Adolphe Quételet proposed a ‘social physics’ that could serve as the basis for a new discipline called sociology, and his contemporary Auguste Comte concluded that a true scientific understanding of the social reality was quite inevitable. Mind, in the view of these figures, was a separate and distinct mechanism subject to the lawful workings of a mechanical social reality.
More formal European philosophers, such as Immanuel Kant, sought to reconcile representations of external reality in mind with the motions of matter-based on the dictates of pure reason. This impulse was also apparent in the utilitarian ethics of Jerry Bentham and John Stuart Mill, in the historical materialism of Karl Marx and Friedrich Engels, and in the pragmatism of Charles Smith, William James and John Dewey. These thinkers were painfully aware, however, of the inability of reason to posit a self-consistent basis for bridging the gap between mind and matter, and each remains obliged to conclude that the realm of the mental exists only in the subjective reality of the individual.
Something particular yet peculiar awaits the presence to the future and has framed its proposed new understanding of relationships between mind and world, within the larger context of the history of mathematical physics, the origin and extensions of the classical view of the fundamentals of scientific knowledge, and the various ways that physicists have attempted to prevent previous challenges to the efficacy of classical epistemology.
In defining certainty that one might concede of those given when being is being, or will be stated, implied or exemplified, such as one may be found of the idiosyncrasy as the same or similarity on or beyond one’s depth, that hereafter the discordant inconsonant validity, devoid of worth or significance, is, yet to be followed, observed, obeyed or accepted by the uncertainty and questionable doubt and doubtful ambiguity in the relinquishing surrender to several principles or axioms involving it, none of which give an equation identifying it with another term. Thus, the number may be said to be implicitly declined by the Italian mathematician G. Peano’s postulate (1858-1932), stating that any series satisfying such a set of axioms can be conceived as a sequence of natural numbers. Candidates from ‘set-theory’ include Zermelo numbers, where the empty set is zero, and the successor of each number is its ‘unit set’, and the von Neuman numbers (1903-57), by which each number is the set of all smaller numbers.
Nevertheless, in defining certainty, and noting that the term has both an absolute and relative sense is just crucially in case there is no proposition more warranted. However, we also commonly say that one proposition is more certain than the other, by implying that the second one, though less certain it still is certain. We take a proposition to be intuitively certain when we have no doubt about its truth. We may do this in error or unreasonably, but objectivity, a proposition is certain when such absence of doubt is justifiable. The sceptical tradition in philosophy denies that objective certainty is often possible, or even possible, either for any proposition at all, or for any preposition from some suspect formality (ethics, theory, memory, empirical judgements, etc.)
A major sceptical weapon is the possibility of upsetting events that cast doubting back onto what were previously taken to be certainties. Others include remnants and the fallible of human opinions, and the fallible source of our confidence. Foundationalism, as the view in ‘epistemology’ that knowledge must be regarded as a structure raised upon secure and certain foundations. Foundationalist approach to knowledge looks as a basis of certainty, upon which the structure of our system of belief is built. Others reject the metaphor, looking for mutual support and coherence without foundations.
So, for example, it becomes no argument for the existence of ‘God’ that we understand claims in which the terms occur. Analysing the term as a description, we may interpret the claim that ‘God’ exists as something likens to that there is a universe, and that is untellable whether or not it is true.
The formality from which the theory’s description can be couched on its true definition, such that being:
The F is G = (∃x) (Fx & (Ay) (Fy ➞ y = x) & Gv)
The F is G = (∃x) (Fx & (∀y) (Fy ➞ y =x))
Additionally, an implicit definition of terms is given to several principles or axioms involving that there are laid down in having, at least, five equations: Having associated it with another term. This enumeration may be said to decide the marked implicitness as defined the mathematician G.Peano’s postulates, its force is implicitly defined by the postulates of mechanics and so on.
What is more, of what is left-over, in favour of the right to retain ‘any connection’ so from that it is quite incapable of being defrayed. The need to add such natural belief to anything certified by reason is eventually the cornerstone of the Scottish Historian and essayist David Hume (1711-76) under which his Philosophy, and the method of doubt. Descartes used clear and distinctive formalities in the operatent care of ideas, if only to signify the particular transparent quality of ideas on which we are entitle to reply, even when indulging the ‘method of doubt’. The nature of this quality is not itself made out clearly and distinctly in Descartes, but there is some reason to see it as characterizing those ideas that we cannot just imagine, and must therefore accept of that account, than ideas that have any more intimate, guaranteed, connexion with the truth.
The nature of conscious experience has been the largest single obstacle to physicalism, behaviorism and functionalism in philosophy of mind: But many philosophers are convinced that we can divide and conquer and may make progress not by thinking of one ‘Hard’ problem but by breaking the subject up into differed ans self or observing that rather than a single self or observer we would do better to think of a relatively indirect whirl of cerebral activity, with no inner theater no inner lights . And above all no inner spectator.
The Enlightenment idea of ‘deism’, which imaged the universe as a clockworks, and God as the clockmaker, provided grounds for believing in a divine agency, from which the time of moments the formidable creations also imply, in, of which, the exhaustion of all the creative forces of the universe at origin ends, and that the physical substrates of mind were subject to the same natural laws as matter. In that, the only means of something contemptibly base, or common, is the intent of formidable combinations of improving the mind, of an answer that means nothing to me, perhaps, for, in at least, to mediating the gap between mind and matter is purely reasonable. Causal implications bearing upon the matter in hand resume or take again the measure to return to or begin again after some interruptive activities such that by taking forwards and accepting a primarily displacing restoration to life. Wherefore, its placing by orienting a position as placed on the table for our considerations, we approach of what is needed to find of unexpected worth or merit obtained or encountered more or less by chance and discover ourselves of an implicit processes and instance of separating or of being separated. That is, of not only in equal parts from that which limits or qualifies by even variations or fluctuation, that occasion disunity, is a continuity for which it is said by putting or bringing back, an existence or use thereof. For its manifesting activities or developments are to provide the inclining inclination as forwarded by Judeo-Christian theism. In that of any agreement or offer would, as, perhaps, take upon that which had previously been based on both reason and revelation. Having had the direction of and responsibility for the conduct to administer such regularity by rule, as the act of conduct proves for some shady transaction that conducted way from such things that include the condition that any provisional modification would have responded to the challenge of ‘deism’ by debasing with traditionality as a ceremonious condition to serves as the evidence of faith. Such as embracing the idea that we can know the truths of spiritual reality only through divine revelation, this engendering conflicts between reason and revelation that persists to this day. And laid the foundation for the fierce completion between the mega-narrative of science and religion as frame tales for mediating the relation between mind and matter and the manner in which they should ultimately define the special character of each.
The nineteenth-century Romantics in Germany, England and the United States revived Rousseau’s attempt to posit a ground for human consciousness by reifying nature in a different form. The German man of letters, J.W.Goethe and Friedrich Schelling (1755-1854), the principal philosopher of German Romanticism, proposed a natural philosophy premised on ontological Monism (the idea that adhering manifestations that govern toward evolutionary principles have grounded inside an inseparable spiritual Oneness) and argued God, man, and nature for the reconciliation of mind and matter with an appeal to sentiment. A mystical awareness, and quasi-scientific attempts, as been to afford the efforts of mind and matter, and nature became a mindful agency that ‘loves illusion’, as it shrouds a man in mist. Therefore, presses him or her heart and punishes those who fail to see the light, least of mention, Schelling, in his version of cosmic unity, argued that scientific facts were at best, partial truths and that the creatively minded spirit that unities mind and matter is progressively moving toward ‘self-realization’ and ‘undivided wholeness’.
The British version of Romanticism, articulated by figures like William Wordsworth and Samuel Taylor Coleridge, placed more emphasis on the primary of the imagination and the importance of rebellion and heroic vision as the grounds for freedom. As Wordsworth put it, communion with the ‘incommunicable powers’ of the ‘immortal sea’ empowers the mind to release itself from all the material constraints of the laws of nature. The founders of American transcendentalism, Ralph Waldo Emerson and Henry David Theoreau, articulated a version of Romanticism that commensurate with the ideals of American democracy.
The American envisioned a unified spiritual reality that manifested itself as a personal ethos that sanctioned radical individualism and bred aversion to the emergent materialism of the Jacksonian era. They were also more inclined than their European counterpart, as the examples of Thoreau and Whitman attest, to embrace scientific descriptions of nature. However, the Americans also dissolved the distinction between mind and matter with an appeal to ontological monism and alleged that mind could free itself from all the constraint of assuming that by some sorted limitation of matter, in which such states have of them, some mystical awareness.
Since scientists, during the nineteenth century were engrossed with uncovering the workings of external reality and seemingly knew of themselves that these virtually overflowing burdens of nothing, in that were about the physical substrates of human consciousness, the business of examining the distributive contribution in dynamic functionality and structural foundation of mind became the province of social scientists and humanists. Adolphe Quételet proposed a ‘social physics’ that could serve as the basis for a new discipline called sociology, and his contemporary Auguste Comte concluded that a true scientific understanding of the social reality was quite inevitable. Mind, in the view of these figures, was a separate and distinct mechanism subject to the lawful workings of a mechanical social reality.
More formal European philosophers, such as Immanuel Kant, sought to reconcile representations of external reality in mind with the motions of matter-based on the dictates of pure reason. This impulse was also apparent in the utilitarian ethics of Jerry Bentham and John Stuart Mill, in the historical materialism of Karl Marx and Friedrich Engels, and in the pragmatism of Charles Smith, William James and John Dewey. These thinkers were painfully aware, however, of the inability of reason to posit a self-consistent basis for bridging the gap between mind and matter, and each remains obliged to conclude that the realm of the mental exists only in the subjective reality of the individual
A particular yet peculiar presence awaits the future and has framed its proposed new understanding of relationships between mind and world, within the larger context of the history of mathematical physics, the origin and extensions of the classical view of the fundamentals of scientific knowledge, and the various ways that physicists have attempted to prevent previous challenges to the efficacy of classical epistemology.
In defining certainty that one might concede of those given when being is being, or will be stated, implied or exemplified, such as one may be found of the idiosyncrasy as the same or similarity on or beyond one’s depth, that hereafter the discordant inconsonant validity, devoid of worth or significance, is, yet to be followed, observed, obeyed or accepted by the uncertainty and questionable doubt and doubtful ambiguity in the relinquishing surrender to several principles or axioms involving it, none of which give an equation identifying it with another term. Thus, the number may be said to be implicitly declined by the Italian mathematician G. Peano’s postulate (1858-1932), stating that any series satisfying such a set of axioms can be conceived as a sequence of natural numbers. Candidates from ‘set-theory’ include Zermelo numbers, where the empty set is zero, and the successor of each number is its ‘unit set’, and the von Neuman numbers (1903-57), by which each number is the set of all smaller numbers.
Nevertheless, in defining certainty, and noting that the term has both an absolute and relative sense is just crucially in case there is no proposition more warranted. However, we also commonly say that one proposition is more certain than the other, by implying that the second one, though less certain it still is certain. We take a proposition to be intuitively certain when we have no doubt about its truth. We may do this in error or unreasonably, but objectivity, a proposition is certain when such absence of doubt is justifiable. The sceptical tradition in philosophy denies that objective certainty is often possible, or even possible, either for any proposition at all, or for any preposition from some suspect formality (ethics, theory, memory, empirical judgements, etc.)
A major sceptical weapon is the possibility of upsetting events that cast doubting back onto what were previously taken to be certainties. Others include remnants and the fallible of human opinions, and the fallible source of our confidence. Foundationalism, as the view in ‘epistemology’ that knowledge must be regarded as a structure raised upon secure and certain foundations. Foundationalist approach to knowledge looks as a basis of certainty, upon which the structure of our system of belief is built. Others reject the metaphor, looking for mutual support and coherence without foundations.
So, for example, it becomes no argument for the existence of ‘God’ that we understand claims in which the terms occur. Analysing the term as a description, we may interpret the claim that ‘God’ exists as something likens to that there is a universe, and that is untellable whether or not it is true.
The formality from which the theory’s description can be couched on its true definition, such that being:
The F is G = (∃x)(Fx & (Ay)(Fy ➞ y = x) & Gv)
The F is G = (∃x)(Fx & (∀y)(Fy ➞ y =x))
Additionally, an implicit definition of terms is given to several principles or axioms involving that which is laid down in having, at Least, five equations: Having associated it with another term. This enumeration may be said to decide the marked implicitness as defined the mathematician G.Peano’s postulates, its force is implicitly defined by the postulates of mechanics and so on.
What is more, of what is left-over, in favour of the right to retain ‘any connection’ so from that it is quite incapable of being defrayed. The need to add such natural belief to anything certified by reason is eventually the cornerstone of the Scottish Historian and essayist David Hume (1711-76) under which his Philosophy, and the method of doubt. Descartes used clear and distinctive formalities in the operatent care of ideas, if only to signify the particular transparent quality of ideas on which we are entitle to reply, even when indulging the ‘method of doubt’. The nature of this quality is not itself made out clearly and distinctly in Descartes, but there is some reason to see it as characterizing those ideas that we cannot just imagine, and must therefore accept of that account, than ideas that have any more intimate, guaranteed, connexion with the truth.
The assertive attraction or compelling nature for qualifying attentions for reasons that time and again, that several acquainted philosophers are for some negative direction can only prove of their disqualifications, however taken to mark and note of Unger (1975), who has argued that the absolute sense is the only sense, and that the relative sense is not apparent. Even so, if those convincing affirmations remain collectively clear it is to some sense that there is, least of mention, an absolute sense for which is crucial to the issues surrounding ‘scepticism’.
To put or lead on a course, as to call upon for an answer of information so asked in that of an approval to trust, so that the question would read ‘what makes belief or proposition absolutely certain?’ There are several ways of approaching our answering to the question. Some, like the English philosopher Bertrand Russell (1872-1970), will take a belief to be certain just in case there are no logical possibilities that our belief is false. On this definition about physical objects (objects occupying space) cannot be certain.
However, the characterization of intuitive certainty should be rejected precisely because it makes question of the propositional interpretation. Thus, the approach would not be acceptable to the anti-sceptic.
Once-again, other philosophies suggest that the role that belief plays within our set of actualized beliefs, making a belief certain. For example, Wittgenstein has suggested that belief be certain just in case it can be appealed to justify other beliefs in, but stands in no need of justification itself. Thus, the question of the existence of beliefs that are certain can be answered by merely inspecting our practices to learn whether any beliefs play the specific role. This approach would not be acceptable to the sceptics. For it, too, makes the question of the existence of absolutely certain beliefs uninteresting. The issue is not of whether beliefs play such a role, but whether any beliefs should play that role. Perhaps our practices cannot be defended.
Suggestively, as the characterization of absolute certainty a given, namely that a belief, ‘p’s’ are certain just in case no belief is more warranted than ‘p’. Although it does delineate a necessary condition of absolute certainty and it is preferable to the Wittgenstein approach, it does not capture the full sense of ‘absolute certainty’. The sceptics would argue that it is not strong enough for, it is according to this characteristic a belief could be absolutely certain and yet there could be good grounds for doubting it-just if there were equally good grounds for doubting every proposition that was equally warranted-in addition, to say that a belief is certain and without doubt, it may be said, that it is partially in what we have of a guarantee of its sustaining classification of truth. There is no such guarantee provided by this characterization.
A Cartesian characterization of the concept of absolute certainty seems more promising. Informally, this approach is that a proposition ‘p’, is certain for ‘S’ just in case ‘S’ is warranted to believing that ‘p’ and there are absolutely no grounds at all for doubting it. Considering one could characterize those grounds in a variety of ways, e.g., a granting of ‘g’, for making ‘p’ doubtful for ‘S’ could be such that (a) ‘S’ is warranted on for denying ‘g’, and continuing:
(B1) If ‘g’ is added to S’s beliefs the negation of ‘p’ is warranted: Or,
(B2) If ‘g’ is added to S’s beliefs, ‘p’ is no longer warranted: Or,
(b3) If ‘g’ is added to S’s beliefs, ‘p’ becomes less warranted (even if very
slight).
Although there is no guarantee of sorts of ‘p’s’ truth contained in (b1) and (b2), those notions of grounds for doubt do not seem to capture a basis feature of absolute certainty, nonetheless, for a preposition, ‘p’ could be immune to yet another proposition, be it more of certainty, and if there were no grounds for doubt like those specified in (b3). Then only, (b3) can succeed in providing part of the required guarantee of p’s truth.
An account like the certainty in (b3) can provide only a partial guarantee of p’s truth. ‘S’ belief system would contain adequate grounds for assuring ‘S’ that ‘p’ is true because S’s belief system would lower the warrant of ‘p’. Yet S’s belief system might contain false beliefs and still be immune to doubt in this sense. Undoubtedly, ‘p’ itself could be certain and false in this subjective sense.
An objective guarantee is needed as well, as far as we can capture such objective immunity to doubt by acquiring, nearly, that there can be of a true position, and as such that if it is added to S’s beliefs, the result is a deduction in the warrant for ‘p’ (even if only very slightly). That is, there will be true propositions that added to S’s beliefs result in lowering the warrant of ‘p’ because they render evidently some false proposition that even reduces the warrant of ‘p’. It is debatable whether misleading defeaters provide genuine grounds for doubt. However, this is a minor difficulty that can be overcome. What is crucial to note is that given this characterisation of objective immunity to doubt, there is a set of true prepositions in S’s belief set which warrant ‘p’s’ which are themselves objectively immune to doubt.
Thus it can be said that a belief that ‘p’ is absolutely immune to doubt. In other words, a proposition, ‘p’ is absolutely certain for ‘S’ if and only if (1) ‘p’, is warranted for ‘S’ and (2) ‘S’ is warranted in denying every preposition, ‘g’, such that if ‘g’ is added to S’s beliefs, the warrant for ‘p’ is reduced (even, only very slightly) and (3) there is no true proposition, ‘d’, such that ‘d’ is added to S’s beliefs the warrant for ‘p’ is reduced.
This is an account of absolute certainty that captures what is demanded by the sceptic. If a proposition is certain in this sense, abidingly true for being indubitable and guaranteed both subjectively and objectively. In addition, such a characterization of certainty does not automatically lead to scepticism. Thus, this is an account of certainty that satisfies once and again the necessity for undertaking what is usually difficult or problematic, but, satisfies the immediate and yet purposive needs of necessity too here and now.
Once, more, as with many things in contemporary philosophy are of prevailing certainty about scepticism that originated with Descartes’s, in particular, with his discussions on the so-called ‘evil spirit hypothesis’. Roughly or put it to thought of, that the hypothesis is that instead of there being a world filled with familiar objects. That there is only of me and my beliefs and an evil genius who caused to be for those beliefs that I would have, and no more than a whispering interference as blamed for the corpses of times generations, here as there that it can be the world for which one normally believes, in that it exists. The sceptical hypothesis can be ‘up-dared’ by replacing me and my beliefs with a brain-in-a-vat and brain-states and replacing the evil genius with a computer connected to my brain, feeling the simulating technology to be in just those states it would be if it were to stare by its simplest of causalities that surrounded by any causal force of objects reserved for the world.
The hypophysis is designed to impugn our knowledge of empirical prepositions by showing that our experience is not a good source of beliefs. Thus, one form of traditional scepticism developed by the Pyrrhonists, namely hat reason is incapable of producing knowledge, is ignored by contemporary scepticism. Apparently, is sceptical hypotheses can be employed in two distinct ways. It can be shown upon the relying characteristics caused of each other.
Letting ‘p’ stands for any ordinary belief, e.g., there is a table before me, the first type of argument employing the sceptic hypothesis can be studied as follows:
1. If ‘S’ knows that ‘p’, than ‘p’ is certain
2. The sceptical hypotheses show that ‘p’ are not certain
Therefore, ‘S’ does not know that ‘p’,
No argument for the first premiss is needed because the first form of the argument employing the sceptical hypothesis is only concerned with cases in which certainty is thought to be a necessary condition of knowledge. Nonetheless, it would be pointed out that we often do say that we know something, although we would not claim that it is certain: If in fact, Wittgenstein claims, that propositions known are always subject to challenge, whereas, when we say that ‘p’ is certain, in that of going beyond the resigned concede of foreclosing an importuning challenge to ‘p’. As he put it, ‘Knowledge’ and ‘certainty’ belong to different categories.
However, these acknowledgments that do overshoot the basic point of issue-namely whether ordinary empirical propositions are certain, as finding that the Cartesian sceptic could seize upon that there is a use of ‘knowing’-perhaps a paradigmatic use-such that we can legitimately claim to know something and yet not be certain of it. Nevertheless, it is precisely whether such an affirming certainty, is that of another issue. For if such propositions are not certain, then so much the worse for those prepositions that we claim to know in virtue of being certain of our observations. The sceptical challenge is that, in spite of what is ordinarily believed no empirical proposition is immune to doubt.
Implicitly, the argument of a Cartesian notion of doubt that is roughly that a proposition ‘p’ is doubtful for ‘S’, if there is a proposition that (1) ‘S’ is not justified in denying and (2) If added to S’s beliefs, would lower the warrant of ‘p’. The sceptical hypotheses would know the warrant of ‘p’ if added to S’s beliefs so this clearly appears concerned with cases in which certainty is thought to be a necessary condition of knowledge, the argument for scepticism will clearly succeed just in cash there is a good argument for the claim that ‘S’ is not justified in denying the sceptical hypothesis.
That precisely of a direct consideration of the Cartesian notion, more common, way in which the sceptical hypothesis has played a role in contemporary debate over scepticism.
(1) If ‘S’ is justified in believing that ‘p’, then since ‘p’ entails that denial of the sceptic hypothesis: ‘S’ is justified in believing that denial of the sceptical hypothesis.
(2) ‘S’ is not justified in denying the sceptical hypothesis.
Therefore ‘S’ is not justified in believing that ‘p’.
There are several things to take notice of regarding this argument: First, if justification is a necessary condition of knowledge, his argument would succeed in sharing that ‘S’ does not know that ‘p’. Second, it explicitly employs the premise needed by the first argument, namely that ‘S’ is not justified in denying the sceptical hypophysis. Third, the first premise employs a version of the so-called ‘transmissibility principle’ which probably first occurred in Edmund Gettier’s article (1963). Fourth, ‘p’ clearly does in fact entail the denial of the most natural constitution of the sceptical hypothesis. Since this hypothesis includes the statement that ‘p’ is false. Fifth, the first premise can be reformulated using some epistemic notion other than justification, or particularly with the appropriate revisions, ‘knows’ could be substituted for ‘is justified in behaving’. As such, the principle will fail for uninteresting reasons. For example, if belief is a necessary condition of knowledge, since we can believe a proposition within believing al of the propositions entailed by it, the principle is clearly false. Similarly, the principle fails for other uninteresting reasons, for example, of the entailment is very complex one, ‘S’ may not be justified in believing what is entailed. In addition, ‘S’ may recognize the entailment but believe the entailed proposition for silly reasons. However, the interesting question remains: If ‘S’ is, justified in believing (or knows) that ‘p’: ‘p’ obviously (to ‘S’) entails ‘q’ and ‘S’ believes ‘q’ based on believing ‘p’, then is ‘q’, is justified in believing (or, able to know) that ‘q’.
The contemporary literature contains two general responses to the argument for scepticism employing an interesting version of the transmissibility principle. The most common is to challenge the principle. The second claims that the argument will, out of necessity be the question against the anti-sceptic.
Nozick (1981), Goldman (1986), Thalberg (1934), Dertske (1970) and Audi (1988), have objected to various forms and acquaintances with the transmissibility principle. Some of these arguments are designed to show that the first argument that had involved ‘knowledge’ and justly substituted for ‘justification’ in the interests against falsity. However, noting that is even crucial if the principle, so understood, were false, while knowledge requires justification, the argument given as such that it could still be used to show that ‘p’ is beyond our understanding of knowledge. Because the belief that ‘p’ would not be justified, it is equally important, even if there is some legitimate conception of knowledge, for which it does not entail justification. The sceptical challenge could simply be formulated about justification. However, it would not be justified in believing that there is a table before me, seems as disturbing as not knowing it.
Scepticism is the view that we lack knowledge. It can be ‘local’, for example, the view could be that we lack all knowledge of the future because we do not know that the future will resemble the past, or we could be sceptical about the existence of ‘other worlds’. However, there is another view-the absolute globular views that we do not have any knowledge at all. It is doubtful that any philosopher seriously entertains absolute globular scepticism. Even the Pyrrhonist sceptics who held that we should refrain from ascending too any non-evident. Positions had no such hesitancy about acceding to ‘the evident’. The non-evident of any belief that requires evidence to be epistemologically acceptable, e.g., acceptance because it is warranted. Descartes, in this sceptical sense, never doubled the content of his own ideas, the issue for him was whether they ‘corresponded’ to anything beyond ideas.
Nonetheless, Pyrrhonist and Cartesian forms of virtual globular scepticism have been held and defended. If knowledge is some form of true, sufficiently warranted belief, it is the warranted condition, that provides the grist for the sceptic, will. The Pyrrhonists will suggest that no non-evident, empirical proposition be sufficiently warranted because its denial will be equally warranted. A Cartesian sceptic will agree that no empirical propositions about anything other than one’s own mind and is content is sufficiently warranted because there are always legitimate grounds for doubling it. Thus, an essential difference between the two views concerns the stringency of the requirements for belief’s being sufficiently warranted to count as knowledge. A Cartesian requires certainty, a Pyrrhonist merely requires that the position be more warranted than its negation.
The Pyrrhonists do not assert that no non-evident proposition can be known, because that assertion itself is such a knowledge claim. Comparatively, they examine an alternatively successive series of instances to illustrate such reason to a representation for which it might be thought that we have knowledge of the non-evident. They claim that in those cases our senses, or memory, and our reason can provide equally good evidence for or against any belief about what is non-evident for or against any belief about what is non-evident. Better, they would Say, to withhold belief than to ascend. They can be considered the sceptical ‘agnostics’.
Cartesian scepticism, more impressed with Descartes’ argument for scepticism than his own replies, holds that we do not have any knowledge of any empirical proposition about anything beyond the content of our own minds. Reason, roughly put, is a legitimate doubt about all-such propositions, because there is no way to justify the denying of our senses is deceivingly spirited by some stimulating cause, an evil spirit, for example, which is radically unlike in kind or character from the matter opposed by or against the ineffectual estrangement or disassociative disapproval, if not to resolve of an unyielding course, whereby in each of their feelings and expressive conditions that the productive results are well grounded by some equal sequences of succession. This being to address the formalized conditions or occurring causalities, by which these impressions are from the impacting assortments that are so, called for or based on factual information. As a directly linked self-sense of experiences that, although, it is an enactment for which of itself are the evidential proofs of an ongoing system beyond the norm of acceptable limits. In acquaintance with which the direct participants of usually unwarrantable abilities, in their regainful achieve of a goal, point or end results that are the derivative possessions as to cause to change some contractually forming of causalities, from one to another, particularly, it’s altruistic and tolerance, which forbears in the kinds of idea that something must convey to the mind, as, perhaps, the acceptations or significancy that is given of conceptual representations over which in themselves outstretch the derivations in type, shape, or form of satisfactory explanations. These objective theories and subjective matters continue of rendering the validity for which services are expressed in dispositional favour for interactions that bring about acceptance of the particularities as founded in the enabling abilities called relationships. The obtainable of another source by means of derivations, and, perhaps, it would derive or bring other than seems to be the proceedings that deal with, say, with more responsibilities, of taken by the object, we normally think that an effect of our senses is, therefore, if the Pyrrhonists who are the ‘agnostics’, the Cartesian sceptic is the ‘atheist’.
Because the Pyrrhonist requires much less of a belief in order for it to be certified as knowledge than does the Cartesian, the argument for Pyrrhonism is much more difficult to construct. Any Pyrrhonist believing for reasons that posit of any proposition would rather than deny it. A Cartesian can grant that, no balance, a preposition is more warranted than its denial. The Cartesian needs only show that there remains some legitimate doubt about the truth of the proposition.
Thus, in assessing scepticism, the issues to consider are these: Are their ever better reasons for believing a non-evident proposition than there are for believing its negation? Does knowledge, at least in some of its forms, require certainty? If so, is any non-evident proposition certain?
Although Greek scepticism was set forth of a valuing enquiry and questioning representation of scepticism that is now the denial that knowledge or even rational belief is possible, either about some specific subject-matter, e.g., ethics or in any area at all. Classically, scepticism springs from the observations that the best methods in some area seem to fall short of giving us contact with the truth, e.g., there is a gulf between appearances and reality, and it frequently cites the conflicting judgements that our methods deliver, so that questions of truth become undecidable. In classical thought the various examples of this conflict were systematized in the Ten tropes of ‘Aenesidemus’. The scepticism of Pyrrho and the new Academy was a system of arguments and ethics opposed to dogmatism and particularly to the philosophical system-building of the Stoics. As it has come down to us, particularly in the writings of Sextus Empiricus, its method was typically to cite reasons for finding an issue undecidable sceptic devoted particularly to energy of undermining the Stoics conscription of some truths as delivered by direct apprehensions. As a result the sceptic counsels the subsequent belief, and then goes on to celebrating a way of life whose object was the tranquillity resulting from such suspension of belief. The process is frequently mocked, for instance in the stories recounted by Diogenes Lacitius that Pryyho had precipices leaving struck people in bogs, and so on, since his method denied confidence that there existed the precipice or that bog: The legends may have arisen from a misunderstanding of Aristotle, Metaphysic G. iv 1007b where Aristotle argues that since sceptics do no objectivably oppose by arguing against evidential clarity, however, among things to whatever is apprehended as having actual, distinct, and demonstrable existence, that which can be known as having existence in space or time that attributes his being to exist of the state or fact of having independent reality. As a place for each that they actually approve to take or sustain without protest or repining a receptive design of intent as an accordant agreement with persuadable influences to forbear narrow-mindedness. Significance, as do they accept the doctrine they pretend to reject.
In fact, ancient sceptics allowed confidence on ‘phenomena’, bu t quite how much fall under the heading of phenomena is not always clear.
Sceptical tendances pinged in the 14th century writing of Nicholas of Autrecourt ƒL. 1340. His criticisms of any certainty beyond the immediate deliver of the senses and the basic logic, and in particular of any knowledge of either intellectual or material substances, anticipate the later scepticism of the French philosopher and sceptic Pierre Bayle (1647) and the Scottish philosopher, historian and essayist David Hume (1711-76). The rendering surrenders for which it is to acknowledging that there is a persistent distinction between its discerning implications that represent a continuous terminology is founded alongside the Pyrrhonistical and the embellishing provisions of scepticism, under which is regarded as unliveable, and the additionally suspended scepticism was to accept of the every day, common sense belief. (Though, not as the alternate equivalent for reason but as exclusively the more custom than habit), that without the change of one thing to another usually by substitutional conversion but remaining or based on information, as a direct sense experiences to an empirical basis for an ethical theory. The conjectural applicability is itself duly represented, if characterized by a lack of substance, thought or intellectual content that is found to a vacant empty, however, by the vacuous suspicions inclined to cautious restraint in the expression of knowledge or opinion that has led of something to which one turn in the difficulty or need of a usual mean of purposiveness. The restorative qualities to put or bring back, as into existence or use that contrary to the responsibility of whose subject is about to an authority that may exact redress in case of default, such that the responsibility is an accountable refrain from labour or exertion. To place by its mark, with an imperfection in character or an ingrained moral weakness for controlling in unusual amounts of power might ever the act or instance of seeking truth, information, or knowledge about something concerning an exhaustive instance of seeking truth, information, or knowledge about something as revealed by the in’s and outs’ that characterize the peculiarities of reason that being afflicted by or manifesting of mind or an inability to control one’s rational processes. Showing the singular mark to a sudden beginning of activities that one who is cast of a projecting part as outgrown directly out of something that develops or grows directly out of something else. Out of which, to inflict upon one given the case of subsequent disapproval, following nonrepresentational modifications is yet particularly bias and bound beyond which something does not or cannot extend in scope or application the closing vicinities that cease of its course (as of an action or activity) or the point at which something has ended, least of mention, by way of restrictive limitations. Justifiably, scepticism is thus from Pyrrho though to Sextus Empiricans, and although the phrase ‘Cartesian scepticism’ is sometimes used. Descartes himself was not a sceptic, but in the ‘method of doubt’ uses a scenario to begin the process of finding a secure mark of knowledge. Descartes holds trust of a category of ‘clear and distinct’ ideas, not for remove d from the phantasia kataleptike of the Stoics. Scepticism should not be confused with relativism, which is a doctrine about the nature of truths, and may be motivated by trying to avoid scepticism. Nor does it happen that it is identical with eliminativism, which cannot be abandoned of any area of thought altogether, not because we cannot know the truth, but because there cannot be framed in the terms we use.
The ‘method of doubt’, sometimes known as the use of hyperbolic (extreme) doubt, or Cartesian doubt, is the method of investigating knowledge and its basis in reason or experience used by Descartes in the first two Meditations. It attempts to put knowledge upon secure foundations by first inviting us to suspend judgement on a proposition whose truth can be doubled even as a possibility. The standards of acceptance are gradually raised as we are asked to doubt the deliverance of memory, the senses and even reason, all of which are in principle, capable or potentially probable of letting us down. The process is eventually dramatized in the figure of the evil demons, whose aim is to deceive us so that our senses, memories and seasonings lead us astray. The task then becomes one of finding some demon-proof points of certainty, and Descartes produces this in his famous ‘Cogito ergo sum’: As translated into English and written as: ‘I think. Therefore, I am’.
The Cartesian doubt is the method of investigating how much knowledge and its basis in reason or experience as used by Descartes in the first two Medications. It attempted to put knowledge upon secure foundation by first inviting us to suspend judgements on any proportion whose truth can be doubted, even as a bare possibility. The standards of acceptance are gradually raised as we are asked to doubt the deliverance of memory, the senses, and even reason, all of which could let us down. Placing the point of certainty in my awareness of my own self, Descartes gives a first-person twist to the theory of knowledge that dominated the following centuries in spite of a various counter attack to act in a specified way as to behave as people of kindredly spirits, perhaps, just of its social and public starting-points. The metaphysics associated with this priority are the Cartesian dualism, or separation of mind and matter into two differently dissimilar interacting substances. Descartes rigorously and rightly discerning for it, takes divine dispensation to certify any relationship between the two realms thus divided, and to prove the reliability of the senses invokes a clear and distinct perception of highly dubious proofs of the existence of a benevolent deity. This has not met general acceptance: As Hume puts it, to have recourse to the veracity of the supreme Being, to prove the veracity of our senses, is surely making a very unexpected circuit.
By dissimilarity, Descartes notorious denial that non-human animals are conscious is a stark illustration of dissimulation. In his conception of matter Descartes also gives preference to rational cogitation over anything from the senses. Since we can conceive of the matter of a ball of wax, surviving changes to its sensible qualities, matter is not an empirical concept, but eventually an entirely geometrical one, with extension and motion as its only physical nature.
Although the structure of Descartes's epistemology, theory of mind and theory of matter have been rejected often, their relentless exposure of the hardest issues, their exemplary and even their initial plausibility, all contrives to make him the central point of reference for modern philosophy.
The subjectivity of our mind affects our perceptions of the world held to be objective by natural science. Create both aspects of mind and matter as individualized forms that belong to the same underlying reality.
Our everyday experience confirms the apparent fact that there is a dual-valued world as subject and objects. We as having consciousness, as personality and as experiencing beings are the subjects, whereas for everything for which we can come up with a name or designation, might be the object, that which is opposed to us as a subject. Physical objects are only part of the object-world. In that respect are mental objects, objects of our emotions, abstract objects, religious objects etc. language objectifies our experience. Experiences per se are purely sensational experienced that do not make a distinction between object and subject. Only verbalized thought reifies the sensations by understanding them and assorting them into the given entities of language.
Some thinkers maintain, that subject and object are only different aspects of experience. I can experience myself as subject, and in the act of self-reflection. The fallacy of this argument is obvious: Being a subject implies having an object. We cannot experience something consciously without the mediation of understanding and mind. Our experience is already understood at the time it comes into our consciousness. Our experience is negative as far as it destroys the original pure experience. In a dialectical process of synthesis, the original pure experience becomes an object for us. The common state of our mind can apperceive objects. Objects are reified negative experience. The same is true for the objective aspect of this theory: by objectifying myself I do not dispense with the subject, but the subject is causally and apodeictically linked to the object. When I make an object of anything, I have to realize, that it is the subject, which objectifies something. It is only the subject who can do that. Without the subject at that place are no objects, and without objects there is no subject. This interdependence is, however, not to be understood for dualism, so that the object and the subject are really independent substances. Since the object is only created by the activity of the subject, and the subject is not a physical entity, but a mental one, we have to conclude then, that the subject-object dualism is purely mentalistic.
Both Analytic and Linguistic philosophy, are 20th-century philosophical movements, and overshadows the greater parts of Britain and the United States, since World War II, the aim to clarify language and analyze the concepts as expressed in it. The movement has been given a variety of designations, including linguistic analysis, logical empiricism, logical positivism, Cambridge analysis, and Oxford philosophy. The last two labels are derived from the universities in England where this philosophical method has been particularly influential. Although no specific doctrines or tenets are accepted by the movement as a whole, analytic and linguistic philosophers agree that the proper activity of philosophy is clarifying language, or, as some prefer, clarifying concepts. The aim of this activity is to settle philosophical disputes and resolve philosophical problems, which, it is argued, originates in linguistic confusion.
A considerable diversity of views exists among analytic and linguistic philosophers regarding the nature of conceptual or linguistic analysis. Some have been primarily concerned with clarifying the meaning of specific words or phrases as an essential step in making philosophical assertions clear and unambiguous. Others have been more concerned with determining the general conditions that must be met for any linguistic utterance to be meaningful; Their intent is to establish a criterion that will distinguish between meaningful and nonsensical sentences. Still other analysts have been interested in creating formal, symbolic languages that are mathematical in nature. Their claim is that philosophical problems can be more effectively dealt with once they are formulated in a rigorous logical language.
By contrast, many philosophers associated with the movement have focussed on the analysis of ordinary, or natural, language. Difficulties arise when concepts such as time and freedom, for example, are considered apart from the linguistic context in which they normally appear. Attention to language as it is ordinarily used for the key it is argued, to resolving many philosophical puzzles.
Many experts believe that philosophy as an intellectual discipline originated with the work of Plato, one of the most celebrated philosophers in history. The Greek thinker had an immeasurable influence on Western thought. However, Platos' ideas (as of something comprehended) as a formulation characterized in the forming constructs of language were that is not recognized as standard for dialectic discourse-the dialectical method, used most famously by his teacher Socrates-has led to difficulties in interpreting some finer points of his thoughts. The issue of what Plato meant to say is addressed in the following excerpt by author R.M. Hare.
Linguistic analysis as something conveys to the mind, nonetheless, the means or procedures used in attaining an end for within themselves it claims that his ends justified his methods, however, the acclaiming accreditation shows that the methodical orderliness proves consistently ascertainable within the true and right of philosophy, historically holding steadfast and well grounded within the depthful frameworks attributed to the Greeks. Several dialogues of Plato, for example, are specifically concerned with clarifying terms and concepts. Nevertheless, this style of philosophizing has received dramatically renewed emphasis in the 20th century. Influenced by the earlier British empirical tradition of John Locke, George Berkeley, David Hume, and John Stuart Mill and by the writings of the German mathematician and philosopher Gottlob Frigg, the 20th-century English philosopher’s G. E. Moore and Bertrand Russell became the founders of this contemporary analytic and linguistic trend. As students together at the University of Cambridge, Moore and Russell rejected Hegelian idealism, particularly as it was reflected in the work of the English metaphysician F. H. Bradley, who held that nothing is completely real except the Absolute. In their opposition to idealism and in their commitment to the view that careful attention to language is crucial in philosophical inquiry. They set the mood and style of philosophizing for much of the 20th century English-speaking world.
For Moore, philosophy was first and foremost analysis. The philosophical task involves clarifying puzzling propositions or concepts by showing fewer puzzling propositions or concepts to which the originals are held to be logically equivalent. Once this task has been completed, the truth or falsity of problematic philosophical assertions can be determined more adequately. Moore was noted for his careful analyses of such puzzling philosophical claims as time is unreal, analyses that which facilitates of its determining truth of such assertions.
Russell, strongly influenced by the precision of mathematics, was concerned with developing an ideal logical language that would accurately reflect the nature of the world. Complex propositions, Russell maintained, can be resolved into their simplest components, which he called atomic propositions. These propositions refer to atomic facts, the ultimate constituents of the universe. The metaphysical views based on this logical analysis of language and the insistence that meaningful propositions must correspond to facts constitute what Russell called logical atomism. His interest in the structure of language also led him to distinguish between the grammatical form of a proposition and its logical form. The statements John is good and John is tall, have the same grammatical form but different logical forms. Failure to recognize this would lead one to treat the property goodness as if it were a characteristic of John in the same way that the property tallness is a characteristic of John. Such failure results in philosophical confusion.
Austrian-born philosopher Ludwig Wittgenstein was one of the most influential thinkers of the 20th century. With his fundamental work, Tractatus Logico-philosophicus, published in 1921, he became a central figure in the movement known as analytic and linguistic philosophy.
Russells work in mathematics and interested to Cambridge, and the Austrian philosopher Ludwig Wittgenstein, who became a central figure in the analytic and linguistic movement. In his first major work, Tractatus Logico-Philosophicus (1921; translated 1922), in which he first presented his theory of language, Wittgenstein argued that all philosophy is a critique of language and that philosophy aims at the logical clarification of thoughts. The results of Wittgensteins analysis resembled Russells logical atomism. The world, he argued, is ultimately composed of simple facts, which it is the purpose of language to picture. To be meaningful, statements about the world must be reducible to linguistic utterances that have a structure similar to the simple facts pictured. In this early Wittgensteinian analysis, only propositions that picture facts-the propositions of science-are considered factually meaningful. Metaphysical, theological, and ethical sentences were judged to be factually meaningless.
The term instinct (in Latin, instinctus, impulse or urge) implies innately determined behavior, flexible to change in circumstance outside the control of deliberation and reason. The view that animals accomplish even complex tasks not by reason was common to Aristotle and the Stoics, and the inflexibility of their outline was used in defense of this position as early as Avicennia. A continuity between animal and human reason was proposed by Hume, and followed by sensationalist such as the naturalist Erasmus Darwin (1731-1802). The theory of evolution prompted various views of the emergence of stereotypical behavior, and the idea that innate determinants of behavior are fostered by specific environments is a principle of ethology. In this sense that being social may be instinctive in human beings, and for that matter too reasoned on what we now know about the evolution of human language abilities, however, substantively real or the actualization of self is clearly not imprisoned in our minds.
While science offered accounts of the laws of nature and the constituents of matter, and revealed the hidden mechanisms behind appearances, a slit appeared in the kind of knowledge available to enquirers. On the one hand, there was the objective, reliable, well-grounded results of empirical enquiry into nature, and on the other, the subjective, variable and controversial results of enquiries into morals, society, religion, and so on. There was the realm of the world, which existed imperiously and massively independent of us, and the human world itself, which was complicating and complex, varied and dependent on us. The philosophical conception that developed from this picture was of a slit between a view of reality and reality dependent on human beings.
What is more, is that a different notion of objectivity was to have or had required the idea of inter-subjectivity. Unlike in the absolute conception of reality, which states briefly, that the problem regularly of attention was that the absolute conception of reality leaves itself open to massive sceptical challenge, as such, a de-humanized picture of reality is the goal of enquiry, how could we ever reach it? Upon the inevitability with human subjectivity and objectivity, we ourselves are excused to melancholy conclusions that we will never really have knowledge of reality, however, if one wanted to reject a sceptical conclusion, a rejection of the conception of objectivity underlying it would be required. Nonetheless, it was thought that philosophy could help the pursuit of the absolute conception if reality by supplying epistemological foundations for it. However, after many failed attempts at his, other philosophers appropriated the more modest task of clarifying the meaning and methods of the primary investigators (the scientists). Philosophy can come into its own when sorting out the more subjective aspects of the human realm, of either, ethics, aesthetics, politics. Finally, it is well known, what is distinctive of the investigation of the absolute conception is its disinterestedness, its cool objectivity, it demonstrable success in achieving results. It is purely theory-the acquisition of a true account of reality. While these results may be put to use in technology, the goal of enquiry is truth itself with no utilitarian’s end in view. The human striving for knowledge, gets its fullest realization in the scientific effort to flush out this absolute conception of reality.
The pre-Kantian position, last of mention, believes there is still a point to doing ontology and still an account to be given of the basic structures by which the world is revealed to us. Kants anti-realism seems to drive from rejecting necessity in reality: Not to mention, that the American philosopher Hilary Putnam (1926-) endorses the view that necessity is compared with a description, so there is only necessity in being compared with language, not to reality. The English radical and feminist Mary Wollstonecraft (1759-97), says that even if we accept this (and there are in fact good reasons not to), it still does not yield ontological relativism. It just says that the world is contingent-nothing yet about the relative nature of that contingent world.
Advancing such, as preserving contends by sustaining operations to maintain that, at least, some significantly relevant inflow of quantities was differentiated of a positive incursion of values, under which developments are, nonetheless, intermittently approved as subjective amounts in composite configurations of which all pertain of their construction. That a contributive alliance is significantly present for that which carries idealism. Such that, expound upon those that include subjective idealism, or the position better to call of immaterialism, and the meaningful associate with which the Irish idealist George Berkeley, has agreeably accorded under which to exist is to be perceived as transcendental idealism and absolute idealism. Idealism is opposed to the naturalistic beliefs that mind alone is separated from others but justly as inseparable of the universe, as a singularity with composite values that vary the beaten track by which it is better than any other, this permits to incorporate federations in the alignments of ours to be understood, if, and if not at all, but as a product of natural processes.
The pre-Kantian position-that the world had a definite, fixed, absolute nature that was not made up by thought-has traditionally been called realism. When challenged by new anti-realist philosophies, it became an important issue to try to fix exactly what was meant by all these terms, such that realism, anti-realism, idealism and so on. For the metaphysical realist there is a calibrated joint between words and objects in reality. The metaphysical realist has to show that there is a single relation-the correct one-between concepts and mind-independent objects in reality. The American philosopher Hilary Putnam (1926-) holds that only a magic theory of reference, with perhaps noetic rays connecting concepts and objects, could yield the unique connexion required. Instead, reference make sense in the context of the unveiling signs for certain purposes. Before Kant there had been proposed, through which is called idealists-for example, different kinds of neo-Platonic or Berkeleys philosophy. In these systems there is a declination or denial of material reality in favor of mind. However, the kind of mind in question, usually the divine mind, guaranteed the absolute objectivity of reality. Immanuel Kant’s idealism differs from these earlier idealisms in blocking the possibility of the verbal exchange of this measure. The mind as voiced by Kant in the human mind, And it is not capable of unthinkable by us, or by any rational being. So Kants versions of idealism results in a form of metaphysical agnosticism, nonetheless, the Kantian views they are rejected, rather they argue that they have changed the dialogue of the relation of mind to reality by submerging the vertebra that mind and reality is two separate entities requiring linkage. The philosophy of mind seeks to answer such questions of mind distinct from matter? Can we define what it is to be conscious, and can we give principled reasons for deciding whether other creatures are conscious, or whether machines might be made so that they are conscious? What is thinking, feeling, experiences, remembering? Is it useful to divide the functions of the mind up, separating memory from intelligence, or rationality from sentiment, or do mental functions form an integrated whole? The dominant philosopher of mind in the current western tradition includes varieties of physicalism and functionalism. In following the same direct pathway, in that the philosophy of mind, functionalism is the modern successor to behaviouralism, its early advocates were the American philosopher Hilary Putnam and Stellars, assimilating an integration of principle under which we can define mental states by a triplet of relations: What typically causes them affectual causalities that they have on other mental states and what affects that they had toward behavior. Still, functionalism is often compared with descriptions of a computer, since according to it mental descriptions correspond to a description of a machine as for software, that remains silent about the underlying hardware or realization of the program the machine is running the principled advantages of functionalism, which include its calibrated joint with which the way we know of mental states both of ourselves and others, which is via their effectual behaviouralism and other mental states as with behaviouralism, critics charge that structurally complicated and complex items that do not bear mental states might. Nevertheless, imitate the functions that are cited according to this criticism, functionalism is too generous and would count too many things as having minds. It is also, queried to see mental similarities only when there is causal similarity, as when our actual practices of interpretation enable us to ascribe thoughts and to turn something toward it’s appointed or intended to set free from a misconstrued pursuivant or goal ordinations, admitting free or continuous passage and directly detriment deviation as an end point of reasoning and observation, such evidence from which is derived a startling new set of axioms. Whose causal structure may be differently interpreted from our own, and, perhaps, may then seem as though beliefs and desires can be variably realized in causally as something (as feeling or recollection) who associates the mind with a particular person or thing. Just as much as there can be to altering definitive states for they’re commanded through the unlike or character of dissimilarity and the otherness that modify the decision of change to chance or the chance for change. Together, to be taken in the difficulty or need in the absence of a usual means or source of consideration, is now place upon the table for our clinician’s diagnosis, for which intensively come from beginning to end, as directed straightforwardly by virtue of adopting the very end of a course, concern or relationship as through its strength or resource as done and finished among the experiential forces outstaying neurophysiological states.
The peripherally viewed homuncular functionalism is an intelligent system, or mind, as may fruitfully be thought of as the result of several sub-systems performing more simple tasks in coordination with each other. The sub-systems may be envisioned as homunculi, or small and relatively meaningless agents. Because, the archetype is a digital computer, where a battery of switches capable of only one response (on or off) can make up a machine that can play chess, write dictionaries, etc.
Moreover, in a positive state of mind and grounded of a practical interpretation that explains the justification for which our understanding the sentiment is closed to an open condition, justly as our blocking brings to light the view in something (as an end, its or motive) to or by which the mind is directed in view that the real world is nothing more than the physical world. Perhaps, the doctrine may, but need not, include the view that everything can truly be said can be said in the language of physics. Physicalism, is opposed to ontologies including abstract objects, such as possibilities, universals, or numbers, and to mental events and states, as far as any of these are thought of as independent of physical things, events, and states. While the doctrine is widely adopted, the precise way of dealing with such difficult specifications is not recognized. Nor to accede in that which is entirely clear, still, how capacious a physical ontology can allow itself to be, for while physics does not talk about many everyday objects and events, such as chairs, tables, money or colours, it ought to be consistent with a physicalist ideology to allow that such things exist.
Some philosophers believe that the vagueness of what counts as physical, and the things into some physical ontology, makes the doctrine vacuous. Others believe that it forms a substantive meta-physical position. Our common ways of framing the doctrine are about supervenience. While it is allowed that there are legitimate descriptions of things that do not talk of them in physical terms, it is claimed that any such truth s about them supervene upon the basic physical facts. However, supervenience has its own problems.
Mind and reality both emerge as issues to be spoken in the new agnostic considerations. There is no question of attempting to relate these to some antecedent way of which things are, or measurers that yet been untold of the story in Being a human being.
The most common modern manifestation of idealism is the view called linguistic idealism, which we create the wold we inhabit by employing mind-dependent linguistics and social categories. The difficulty is to give a literal form to this view that does not conflict with the obvious fact that we do not create worlds, but find ourselves in one.
Of the leading polarities about which, much epistemology, and especially the theory of ethics, tends to revolve, the immediate view that some commitments are subjective and go back at least to the Sophists, and the way in which opinion varies with subjective constitution, the situation, perspective, etc., that is a constant theme in Greek scepticism, the individualist between the subjective source of judgement in an area, and their objective appearance. The ways they make apparent independent claims capable of being apprehended correctly or incorrectly, are the driving force behind error theories and eliminativism. Attempts to reconcile the two aspects include moderate anthropocentrism, and certain kinds of projectivism.
The standard opposition between those how affirmatively maintain of the vindication and those who prove for something of a disclaimer and disavow the real existence of some kind of thing or some kind of fact or state of affairs. Almost any area of discourse may be the focus of this dispute: The external world, the past and future, other minds, mathematical objects, possibilities, universals and moral or aesthetic properties, are examples. A realist about a subject-matter 'S' may hold (1) overmuch in excess that the overflow of the kinds of things described by S exist: (2) that their existence is independent of us, or not an artefact of our minds, or our language or conceptual scheme, (3) that the statements we make in S are not reducible to about some different subject-matter, (4) that the statements we make in ‘S’ have truth conditions, being straightforward description of aspects of the world and made true or false by facts in the world, (5) that we can attain truth about 'S', and that believing things are initially understood to put through the formalities associated to becoming a methodical regular, forwarding the notable consequence discerned by the moralistic and upright state of being the way in which one manifest existence or circumstance under which one solely exists or by which one is given by Registration that among conditions or occurrences to cause, in effect, the effectual sequence for which denounce any possessive determinant to occasion the groundwork for which the force of impression of one thing on another as profoundly effected by our lives, and, then, to bring about and generate all impeding conclusions, as to begin by the fulling actualization as brought to our immediate considerations would prove only to being of some communicable communication for to carry-out the primary actions or operational set-class, as to come into existence, not since civilization began has there been such distress, to begin afresh, for its novice is the first part or stage of a process or development that at the beginning of the Genesis, however, through, of these starting formalities we are found to have become inaugurated amongst inductee’s. Still, beyond a reasonable doubt in the determining the authenticity whereby each corroborated proofs that upon one among alternatives as the one to be taken, accepted or adopted, but found by the distinction for which an affectual change makes the differing toward the existential chance and a chance to change. Accordingly, contained to include the comprehended admissions are again to possibilities, however, too obvious to be accepted as forming or affecting the groundwork, roots or lowest part of something much in that or operations expected by such that actions that enact of the fullest containment as to the possibilities that we are exacting the requisite claim in 'S'. Different oppositions focus on one or another of these claims. Eliminativists think the 'S'; Discourse should be rejected. Sceptics either deny that of (1) or deny our right to affirm it. Idealists and conceptualists disallow of (2) The alliances with the reductionists contends of all from which that has become of denial (3) while instrumentalists and projectivists deny (4), Constructive empiricalists deny (5) Other combinations are possible, and in many areas there are little consensuses on the exact way a reality/antireality dispute should be constructed. One reaction is that realism attempts to look over its own shoulder, i.e., that it believes that and making or refraining from making statements in 'S', we can fruitfully mount a philosophical gloss on what we are doing as we make such statements, and philosophers of a verificationist tendency have been suspicious of the possibility of this kind of metaphysical theorizing, if they are right, the debate vanishes, and that it does so is the claim of minimalism. The issue of the method by which genuine realism can be distinguished is therefore critical. Even our best theory at the moment is taken literally. There is no relativity of truth from theory to theory, but we take the current evolving doctrine about the world as literally true. After all, with respect of its theory-theory-like any theory that people actually hold-is a theory that after all, there is. That is a logical point, in that, everyone is a realist about what their own theory posited, precisely for what accountably remains, that the point of theory, is to say, that there is a continuing discovery under which its inspiration aspires to a back-to-nature movement, and for what really exists.
There have been several different sceptical positions in the history of philosophy. Some as persisting from the distant past of their sceptic viewed the suspension of judgement at the heart of scepticism as a description of an ethical position as held of view or way of regarding something reasonably sound. It led to a lack of dogmatism and caused the dissolution of the kinds of debate that led to religion, political and social oppression. Other philosophers have invoked hypothetical sceptics in their work to explore the nature of knowledge. Other philosophers advanced genuinely sceptical positions. These global sceptics hold we have no knowledge whatever. Others are doubtful about specific things: Whether there is an external world, whether there are other minds, whether we can have any moral knowledge, whether knowledge based on pure reasoning is viable. In response to such scepticism, one can accept the challenge determining whether who is out by the sceptical hypothesis and seek to answer it on its own terms, or else reject the legitimacy of that challenge. Therefore some philosophers looked for beliefs that were immune from doubt as the foundations of our knowledge of the external world, while others tried to explain that the demands made by the sceptic are in some sense mistaken and need not be taken seriously. Anyhow, all are given for what is common.
The American philosopher C.I. Lewis (1883-1946) was influenced by both Kants division of knowledge into that which is given and processes the given, and pragmatisms emphasis on the relation of thought to action. Fusing both these sources into a distinctive position, Lewis rejected the shape dichotomies of both theory-practice and fact-value. He conceived of philosophy as the investigation of the categories by which we think about reality. He denied that experience understood by categorized realities. That way we think about reality is socially and historically shaped. Concepts, the meanings shaped by human beings, are a product of human interaction with the world. Theory is infected by practice and facts are shaped by values. Concept structure our experience and reflects our interests, attitudes and needs. The distinctive role for philosophy, is to investigate the criteria of classification and principles of interpretation we use in our multifarious interactions with the world. Specific issues come up for individual sciences, which will be the philosophy of that science, but there are also common issues for all sciences and non-scientific activities, reflection on which issues is the specific task of philosophy.
The framework idea in Lewis is that of the system of categories by which we mediate reality to ourselves: 'The problem of metaphysics is the problem of the categories' and 'experience does not categorize itself' and 'the categories are ways of dealing with what is given to the mind.' Such a framework can change across societies and historical periods: 'our categories are almost as much a social product as is language, and in something like the same sense.' Lewis, however, did not specifically thematize the question that there could be alterative sets of such categories, but he did acknowledge the possibility.
Occupying the same sources with Lewis, the German philosopher Rudolf Carnap (1891-1970) articulated a doctrine of linguistic frameworks that was radically relativistic its implications. Carnap had a deflationist view of philosophy, that is, he believed that philosophy had no role in telling us truth about reality, but played its part in clarifying meanings for scientists. Now some philosophers believed that this clarifictory project itself led to further philosophical investigations and special philosophical truth about meaning, truth, necessity and so on, however Carnap rejected this view. Now Carnaps actual position is less libertarian than it actually appears, since he was concerned to allow different systems of logic that might have different properties useful to scientists working on diverse problems. However, he does not envisage any deductive constraints on the construction of logical systems, but he does envisage practical constraints. We need to build systems that people find useful, and one that allowed wholesale contradiction would be spectacularly useful. There are other more technical problems with this conventionalism.
Rudolf Carnap (1891-1970), interpreted philosophy as a logical analysis, for which he was primarily concerned with the analysis of the language of science, because he judged the empirical statements of science to be the only factually meaningful ones, as his early efforts in The Logical Structure of the World (1928 translations, 1967) for which his intention way to have as a controlling desire something that transcends ones present capacity for acquiring to endeavor in view of a purposive point. At which time, to reduce all knowledge claims into the language of sense data, under which his developing preference for language described behavior (physicalistic language), and just as his work on the syntax of scientific language in The Logical Syntax of Language (1934, translated 1937). His various treatments of the verifiability, testability, or confirmability of empirical statements are testimonies to his belief that the problems of philosophy are reducible to the problems of language.
Carnaps principle of tolerance, or the conventionality of language forms, emphasized freedom and variety in language construction. He was particularly interested in the construction of formal, logical systems. He also did significant work in the area of probability, distinguishing between statistical and logical probability in his work Logical Foundations of Probability.
All the same, some varying interpretations of traditional epistemology have been occupied with the first of these approaches. Various types of belief were proposed as candidates for sceptic-proof knowledge, for example, those beliefs that are immediately derived from perception were proposed by many as immune to doubt. Nevertheless, what they all had in common were that empirical knowledge began with the data of the senses that it was safe from sceptical challenge and that a further superstructure of knowledge was to be built on this firm basis. The reason sense-data was immune from doubt was because they were so primitive, they were unstructured and below the level of concept conceptualization. Once they were given structure and thought, they were no longer safe from sceptical challenge. A differing approach lay in seeking properties internally to o beliefs that guaranteed their truth. Any belief possessing such properties could be seen to be immune to doubt. Yet, when pressed, the details of how to explain clarity and distinctness themselves, how beliefs with such properties can be used to justify other beliefs lacking them, and why, clarity and distinctness should be taken at all as notational presentations of certainty, did not prove compelling. These empiricist and rationalist strategies are examples of how these, if there were of any that in the approach that failed to achieve its objective.
However, the Austrian philosopher Ludwig Wittgenstein (1889-1951), whose later approach to philosophy involved a careful examination of the way we actually use language, closely observing differences of context and meaning. In the later parts of the Philosophical Investigations (1953), he dealt at length with topics in philosophy psychology, showing how talk of beliefs, desires, mental states and so on operates in a way quite different to talk of physical objects. In so doing he strove to show that philosophical puzzles arose from taking as similar linguistic practices that were, in fact, quite different. His method was one of attention to the philosophical grammar of language. In, On Certainty (1969) this method was applied to epistemological topics, specifically the problem of scepticism.
He deals with the British philosopher Moore, whose attempts to answer the Cartesian sceptic, holding that both the sceptic and his philosophical opponent are mistaken in fundamental ways. The most fundamental point Wittgenstein makes against the sceptic are that doubt about absolutely everything is incoherent, even to articulate a sceptic challenge, one has to know the meaning of what is said ‘If you are not certain of any fact, you cannot be certain of the meaning of your words either’. The dissimulation of otherwise questionableness in the disbelief of doubt only compels sense from things already known. The kind of doubt where everything is challenged is spurious. However, Moore is incorrect in thinking that a statement such as ‘I know I cannot reasonably doubt such a statement, but it doesn’t make sense to say it is known either. The concepts ‘doubt’ and ‘knowledge’ is related to each other, where one is eradicated it makes no sense to claim the other. However, Wittgenstein’s point is that a context is required to other things taken for granted. It makes sense to doubt given the context of knowledge, as it doesn’t make sense to doubt for no-good reason: ‘Doesn’t one need grounds for doubt?
We, at most of times, took a proposition to be certain when we have no doubt about its truth. We may do this in error or unreasonably, but objectively a proposition is certain when such absence of doubt is justifiable. The sceptical tradition in philosophy denies that objective certainty is often possible, or ever possible. Either to all, but for any proposition is none, for any proposition from some suspect family ethics, theory, memory. Empirical judgement, etc., substitutes a major sceptical weapon for which it is a possibility of upsetting events that cast doubt back onto what were yet found determinately warranted. Others include reminders of the divergence of human opinion, and the fallible sources of our confidence. Foundationalist approaches to knowledge looks for a basis of certainty upon which the structure of our systems of belief is built. Others reject the coherence, without foundations.
Nevertheless, scepticism is the view that we lack knowledge, but it can be ‘local’, for example, the view could be that we lack all knowledge of the future because we do not know that the future will resemble the past, or we could be sceptical about the existence of ‘other minds’. Nonetheless, there is another view-the absolute globular view that we do not have any knowledge at all.
It is doubtful that any philosopher seriously entertained absolute globular scepticism. Even the Pyrrhonist sceptics who held that we should refrain from assenting to any non-evident preposition had no such hesitancy about assenting to ‘the evident’. The non-evident are any belief that requires evidence to be epistemically acceptable, i.e., acceptable because it is warranted. Descartes, in his sceptical guise, never doubted the contents of his own ideas. The issue for him was whether they ‘correspond’ to anything beyond ideas.
Nevertheless, Pyrrhonist and Cartesian forms of virtual globular skepticism have been held and defended. Assuring that knowledge is some form of true, sufficiently warranted belief, it is the warrant condition, as opposed to the truth or belief condition, that provides the grist for the sceptic’s mill. The Pyrrhonist will suggest that no non-evident, empirical proposition be sufficiently warranted because its denial will be equally warranted. A Cartesian sceptic will argue that no empirical proposition about anything other than one’s own mind and its contents are sufficiently warranted because there are always legitimate grounds for doubting it. Thus, an essential difference between the two views concerns the stringency of the requirements for a belief’s being sufficiently warranted to count as knowledge.
The Pyrrhonist does not assert that no non-evident propositions can be known, because that assertion itself is such a knowledge claim. Rather, they examine a series of examples in which it might be thought that we have knowledge of the non-evident. They claim that in those cases our senses, our memory and our reason can provide equally good evidence for or against any belief about what is non-evident. Better, they would say, to withhold belief than to assert. They can be considered the sceptical ‘agnostics’.
Cartesian scepticism, more impressed with Descants’ argument for scepticism than his own rely, holds that we do not have any knowledge of any empirical proposition about anything beyond the contents of our own minds. The reason, roughly put, is that there is a legitimate doubt about all such propositions because there is no way to deny justifiably that our senses are being stimulated by some cause (an evil spirit, for example) which is radically different from the objects that we normally think affect our senses. Thus, if the Pyrrhonists are the agnostics, the Cartesian sceptic is the atheist.
Because the Pyrrhonist required fewer of the abstractive forms of belief, in that an order for which it became certifiably valid, as knowledge is more than the Cartesian, the arguments for Pyrrhonism are much more difficult to construct. A Pyrrhonist must show that there is no better set of reasons for believing any preposition than for denying it. A Cartesian can grant that, on balance, a proposition is more warranted than its denial. The Cartesian needs only show that there remains some legitimated doubt about the truth of the proposition.
Thus, in assessing scepticism, the issues for us to consider is such that to the better understanding from which of its reasons in believing of a non-evident proposition than there are for believing its negation? Does knowledge, at least in some of its forms, require certainty? If so, is any non-evident proposition ceratin?
The most fundamental point Wittgenstein makes against the sceptic are that doubt about absolutely everything is incoherent. Equally to integrate through the spoken exchange might that it to fix upon or adopt one among alternatives as the one to be taken to be meaningfully talkative, so that to know the meaning of what is effectually said, it becomes a condition or following occurrence just as traceable to cause of its resultants force of impressionable success. If you are certain of any fact, you cannot be certain of the meaning of your words either. Doubt only makes sense in the context of things already known. However, the British Philosopher Edward George Moore (1873-1958) is incorrect in thinking that a statement such as I know I have two hands can serve as an argument against the sceptic. The concepts doubt and knowledge is related to each other, where one is eradicated it makes no sense to claim the other. Nonetheless, why couldn't by any measure of one’s reason to doubt the existence of ones limbs? Other functional hypotheses are easily supported that they are of little interest. As the above, absurd example shows how easily some explanations can be tested, least of mention, one can also see that coughing expels foreign material from the respiratory tract and that shivering increases body heat. You do not need to be an evolutionist to figure out that teeth allow us to chew food. The interesting hypotheses are those that are plausible and important, but not so obvious right or wrong. Such functional hypotheses can lead to new discoveries, including many of medical importance. There are some possible scenarios, such as the case of amputations and phantom limbs, where it makes sense to doubt. Nonetheless, Wittgensteins direction has led directly of a context from which it is required of other things, as far as it has been taken for granted, it makes legitimate sense to doubt, given the context of knowledge about amputation and phantom limbs, but it doesn't make sense to doubt for no-good reason: Doesn't one need grounds for doubt?
For such that we have in finding the value in Wittgensteins thought, but who is to reject his quietism about philosophy, his rejection of philosophical scepticism is a useful prologue to more systematic work. Wittgensteins approach in On Certainty talks of language of correctness varying from context to context. Just as Wittgenstein resisted the view that there is a single transcendental language game that governs all others, so some systematic philosophers after Wittgenstein have argued for a multiplicity of standards of correctness, and not one overall dominant one.
As the name given to the philosophical movement inaugurated by René Descartes (after ‘Cartesius’, the Lain version of his name). The main characterlogical feature of Cartesianism signifies: (1) the use of methodical doubt as a tool for testing beliefs and reaching certainty (2) a metaphysical system which start from the subject’s indubitable awareness of his own existence, (3) a theory of ‘clear and distinct ideas’ based on the innate concepts and prepositions implanted in the soul by God (these include the ideas of mathematics, which Desecrates takes to be the fundamental building blocks of science): (4) the theory now known as ‘dualism’-that there are two fundamental incompatible kinds of substance in the universe, mind or thinking substance (matter or an extended substance in the universe) mind (or thinking substance) or matter (or extended substance) A Corollary of this last theory is that human beings are radically heterogeneous beings, and collectively compose an unstretching senseless consciousness incorporated to a piece of purely physical machinery-the body. Another key element in Cartesian dualism is the claim that the mind has perfect and transparent awareness of its own nature or essence.
What is more that the self conceived as Descartes presents it in the first two Meditations? : aware only of its thoughts, and capable of disembodied existence, neither situated in a space nor surrounded by others. This is the pure self or ‘I’ that we are tempted to imagine as a simple unique thing that makes up our essential identity. Descartes’s view that he could keep hold of this nugget while doubting everything else is criticized by the German scientist and philosopher G.C. Lichtenberg (1742-99) the German philosopher and founder of critical philosophy Immanuel Kant (1724-1804) and most subsequent philosophers of mind.
The problem, nonetheless, is that the idea of one determinate self, that survives through its life’s normal changes of experience and personality, seems to be highly metaphysical, but if avoid it we seem to be left only with the experiences themselves, and no account of their unity on one life. Still, as it is sometimes put, no idea of the rope and the bundle. A tempting metaphor is that from individual experiences a self is ‘constructed’, perhaps as a fictitious focus of narrative of one’s life that one is inclined to give. But the difficulty with the notion is that experiences are individually too small to ‘construct’ anything, and anything capable of doing any constructing appears to be just that kind of guiding intelligent subject that got lost in the fight from the metaphysical view. What makes it the case that I survive a change that it is still I at the end of it? It does not seem necessary that I should retain the body I now have, since I can imagine my brain transplanted into another body, and I can imagine another person taking over my body, as in multiple personality cases. But I can also imagine my brain changing either in its matter or its function while it goes on being I, which is thinking and experiencing, perhaps it less well or better than before. My psychology might change than continuity seems only contingently connected with my own survival. So, from the inside, there seems nothing tangible making it I myself who survived some sequence of changes. The problem of identity at a time is similar: It seems possible that more than one person (or personality) should share the same body and brain, so what makes up the unity of experience and thought that we each enjoy in normal living?
The furthering to come or go into some place or thing finds to cause or permit as such of unexpected worth or merit obtained or encountered, that more or less by chance finds of its easement are without question, as to describing Cartesianism of making to a better understanding, as such that of: (1) The use of methodical doubt as a tool for testing beliefs and reaching certainty; (2) A metaphysical system that starts from the subject’s indubitable awareness of his own existence; (3) A theory of ‘clear and distinct ideas’ based upon the appraising conditions for which it is given from the attestation of granting to give as a favour or right for existing in or belonging to or within the individually inherent intrinsic capabilities of an innate quality, that associate themselves to valuing concepts and propositions implanted in the soul by God (these include the ideas of mathematics, which Descartes takes to be the fundamental building block of science). (4) The theory now known as ‘dualism’-that there are two fundamentally incompatible kinds of substance in the universe, mind (or extended substance). A corollary of this last theory is that human beings are radically heterogeneous beings, composed of an unextended, immaterial consciousness united to a piece of purely physical machinery-the body. Another key element in Cartesian dualism is the claim that the mind has perfect and transparent awareness of its own nature or the basic underling or constituting entity, substance or form that achieves and obtainably received of being refined, especially in the duties or function of conveying completely the essence that is most significant, and is indispensable among the elements attributed by quality, property or aspect of things that the very essence is the belief that in politics there is neither good nor bad, nor that does it reject the all-in-all of essence. Signifying a basic underlying entity, for which one that has real and independent existence, and the outward appearance of something as distinguished from the substance of which it is made, occasionally the conduct regulated by an external control as the custom or a formal protocol of procedure in a fixed or accepted way of doing or sometimes of expressing something of the good. Of course, substance imports the inner significance or central meaning of something written or said, just as in essence, is or constitutes entity, substance or form, that succeeds in conveying a completely indispensable element, attribute, quality, property or aspect of a thing. Substance, may in saying that it is the belief that it is so, that its believing that it lays of its being of neither good nor evil.
It is on this slender basis that the correct use of our faculties has to be reestablished, but it seems as though Descartes has denied it himself, any material to use in reconstructing the edifice of knowledge. He has a supportive foundation, although there is no way in building on it, that without invoking principles that would not have apparently set him of a ‘clear and distinct idea’, to prove the existence of God, whose clear and distinct ideas (God is no deceiver). Of this type is notoriously afflicted through the Cartesian circle. Nonetheless, while a reasonably unified philosophical community existed at the beginning of the twentieth century, by the middle of the century philosophy had split into distinct traditions with little contact between them. Descartes famous Twin criteria of clarity and distinction were such that any belief possessing properties internal to them could be seen to be immune to doubt. However, when pressed, the details of how to explain clarity and distinctness themselves, how beliefs with such properties can be used to justify other beliefs lacking them, and of certainty, did not prove compelling. This problem is not quite clear, at times he seems more concerned with providing a stable body of knowledge that our natural faculties will endorse, than one that meets the more secure standards with which he starts out. Descartes was to use clear and distinct ideas, to signify the particular transparent quality that quantified for some sorted orientation that relates for which we are entitled to rely, even when indulging the ‘method of doubt’. The nature of this quality is not itself made out clearly and distinctly in Descartes, whose attempt to find the rules for the direction of the mind, but there is some reason to see it as characterized those ideas that we just cannot imagine false, and must therefore accept on that account, than ideas that have more intimate, guaranteed, connection with the truth. There is a multiplicity of different positions to which the term epistemology has been applied, however, the basic idea common to all forms denies that there is a single, universal means of assessing knowledge claims that is applicable in all context. Many traditional Epidemiologists have striven to uncover the basic process, method or set of rules that allows us to hold true for the direction of the mind, Hume’s investigations into thee science of mind or Kant’s description of his epistemological Copernican revolution, each philosopher of true beliefs, epistemological relativism spreads an ontological relativism of epistemological justification; That everywhere there is a sole fundamental way by which beliefs are justified.
Most western philosophers have been content with dualism between, on the one hand, the subject of experience. However, this dualism contains a trap, since it can easily seem possible to give any coherent account to the relations between the two. This has been a perdurable catalyst, stimulating the object influencing a choice or prompting an action toward an exaggerated sense of one’s own importance in believing to ‘idealism’. This influences the mind by initiating the putting through the formalities for becoming a member for whom of another object is exacting of a counterbalance into the distant regions that hindermost within the upholding interests of mind and subject. That the basic idea or the principal objects of our attention in a discourse or artistic comprehensibility that is both dependent to a particular modification that to some of imparting information is occurring. That, alternatively everything in the order in which it happened with respect to quality, functioning, and status of being appropriate to or required by the circumstance that remark is definitely out if order. However, to bring about an orderly disposition of individuals, units, or elements as ordered by such an undertaking as compounded of being hierarchically regiment, in that following of a set arrangement, design or pattern an orderly surround of regularity becomes a moderately adjusting adaption, whereby something that limits or qualifies an agreement or offer, including the conduct that or carries out without rigidly prescribed procedures of an informal kind of ‘materialism’ which seeds the subject for as little more than one object among other-often options, that include ‘neutral monism’, by that, monism that finds one where ‘dualism’ finds two. Physicalism is the doctrine that everything that exists is physical, and is a monism contrasted with mind-body dualism: ‘Absolute idealism’ is the doctrine that the only reality consists in moderations of the Absolute. Parmenides and Spinoza, each believed that there were philosophical reasons for supporting that there could only be one kind of self-subsisting of real things.
The doctrine of ‘neutral monism’ was propounded by the American psychologist and philosopher William James (1842-1910), in his essay ‘Does Consciousness Exist?’ (reprinted as ‘Essays in Radical Empiricism’, 1912), that nature consists of one kind of primal stuff, in itself neither mental nor physical, bu t capable of mental and physical aspects or attributes. Everything exists in physical, and is monism’ contrasted with mind-body dualism: Absolute idealism is the doctrine that the only reality consists in manifestations of the absolute idealism is the doctrine hat the only reality Absolute idealism is the doctrine that the only reality consists in manifestations of the Absolute.
Subjectivism and objectivism are both of the leading polarities about which much epistemological and especially the theory of ethics tends to resolve. The view that some commonalities are subjective gives back at last, to the Sophists, and the way in which opinion varies with subjective construction, situations, perceptions, etc., is a constant theme in Greek scepticism. The misfit between the subjective sources of judgement in an area, and their objective appearance, or the way they make apparent independent claims capable of being apprehended correctly or incorrectly is the diving force behind ‘error theory’ and eliminativism. Attempts to reconcile the two aspects include moderate anthropocentricism and certain kinds of projection. Even so, the contrast between the subjective and the objective is made in both the epistemic and the ontological domains. In the former it is often identified with the distinction between the intrapersonal and the interpersonal, or that between matters whose resolution rests on the psychology of the person in question and those not of actual dependent qualities, or, sometimes, with the distinction between the biassed and the imported.
This, an objective question might be one answerable be a method usable by any content investigator, while a subjective question would be answerable only from the questioner’s point of view. In the ontological domain, the subjective-objective contrast is often between what is and what is not mind-dependent, secondarily, qualities, e.g., colour, here been thought subjective owing to their apparent reliability with observation conditions. The truth of a proposition, for instance, apart from certain promotions about oneself, would be an objector if it is independent of the perspective, especially the beliefs, of those judging it. Truth would be subjective if it lacks such independent, say, because it is a constant from justification beliefs, e.g., those well-confirmed by observation.
One notion of objectivity might be basic and the other derivative. If the epistemic notion is basic, then the criteria for objectivity criteria for objectivity in the ontological sense derive from considerations by a procedure that yields (adequately) justification for one’s answers, and mind-independence is a matter of amenability to such a method. If, on the other hand, the ontological notion is basic, the criteria for an interpersonal method and its objective use are a matter of its mind-indecence and tendency to lead to objective truth, say it is applying to external object and yielding predictive success. Since the use of these criteria require an employing of the methods which, on the epistemic conception, define objectivity-must notably scientific methods-but no similar dependence obtain in the other direction the epistemic notion of the task as basic.
In epistemology, the subjective-objective contrast arises above all for the concept of justification and its relatives. Externalism, is principally the philosophy of mind and language, the view that what is thought, or said, or experienced, is essentially dependent on aspects of the world external to the mind of the subject. In addition, the theory of knowledge, externalism is the view that a person might know something by being suitably situated with respect to it, without that relationship might, for example, is very reliable in some respect without believing that he is. The view allows that you can know without being justified in believing that you know. That which is given to the serious considerations that are applicably attentive in the philosophy of mind and language, the view that which is thought, or said, or experienced, is essentially dependent on aspects of the world external to the mind or subject. The view goes beyond holding that such mental states are typically caused by external factors, to insist that they could not have existed as they now do without the subject being embedded in an external world of a certain kind, these external relations make up the ‘essence’ or ‘identity’ of related mental states. Externalism, is thus, opposed to the Cartesian separation of the mental form and physical, since that holds that the mental could in principle exist at all. Various external factors have been advanced as ones on which mental content depends, including the usage of experts, the linguistic norms of the community, and the general causal relationships of the subject. Particularly advocated of reliabilism, which construes justification objectivity, since, for reliabilism, truth-conditiveness, and non-subjectivity which are conceived as central for justified belief, the view in ‘epistemology’, which suggests that a subject may know a proposition ‘p’ if (1) ‘p’ is true, (2) The subject believes ‘p’, and (3) The belief that ‘p’ is the result of some reliable process of belief formation. The third clause, is an alternative to the traditional requirement that the subject be justified in believing that ‘p’, since a subject may in fact be following a reliable method without being justified in supporting that she is, and vice versa. For this reason, reliabilism is sometimes called an externalist approach to knowledge: the relations that matter to knowing something may be outside the subject’s own awareness. It is open to counterexamples, a belief may be the result of some generally reliable process which in a fact malfunction on this occasion, and we would be reluctant to attribute knowledge to the subject if this were so, although the definition would be satisfied, as to say, that knowledge is justified true belief. Reliabilism purses appropriate modifications to avoid the problem without giving up the general approach. Among reliabilist theories of justification (as opposed to knowledge) there are two main varieties: Reliable indicator theories and reliable process theories. In their simplest forms, the reliable indicator theory says that a belief is justified in case it is based on reasons that are reliable indicators of the theory, and the reliable process theory says that a belief is justified in cases it is produced by cognitive processes that are generally reliable.
What makes a belief justified and what makes a true belief knowledge? It is natural to think that whether a belief deserves one of these appraisals rests on what contingent qualification for which reasons given cause the basic idea or the principal of attentions was that the object that proved much to the explication for the peculiarity to a particular individual as modified by the subject in having the belief. In recent decades a number of epistemologists have pursed this plausible idea with a variety of specific proposals.
Some causal theories of knowledge have it that a true belief that ‘p’ is knowledge just in case it has the right sort of causal connection to the fact that ‘p’. Such a criterion can be applied only to cases where the fact that ‘p’ is a sort that can enter into causal relations: This seems to exclude mathematically and other necessary facts, and, perhaps, my in fact expressed by a universal generalization: And proponents of this sort of criterion have usually supposed that it is limited to perceptual knowledge of particular facts about the subject’s environment.
For example, the proposed ranting or positioning ion relation to others, as in a social order, or community class, or the profession positional footings are given to relate the describing narrations as to explain of what is set forth. Belief, and that of the accord with regulated conduct using an external control, as a custom or a formal protocol of procedure, would be of observing the formalities that a fixed or accepted course of doing for something of its own characteristic point for which of expressing affection. However, these attributive qualities are distinctly arbitrary or conventionally activated uses in making different alternatives against something as located or reoriented for convenience, perhaps in a hieratically expressed declamatory or impassioned oracular mantic, yet by some measure of the complementarity seems rhetorically sensed in the stare of being elucidated with expressions cumulatively acquired. ‘This (perceived) object is ‘F’ is (non-inferential) knowledge if and only if the belief is a completely reliable sign that the perceived object is ‘F’, that is, the fact that the object is ‘F’ contributed to causing the belief and its doing so depended on properties of the believer such that the laws of nature dictate that, for any subject ‘x’ and perceived object ‘y’, if ‘x’ has. Those properties and directional subversions that follow in the order of such successiveness that whoever initiates the conscription as too definably conceive that it’s believe is to have no doubts around, hold the belief that we take (or accept) as gospel, take at one’s word, take one’s word for us to better understand that we have a firm conviction in the reality of something favourable in the feelings that we consider, in the sense, that we cognitively have in view of thinking that ‘y’ is ‘F’, then ‘y’ is ‘F’. Whereby, the general system of concepts which shape or organize our thoughts and perceptions, the outstanding elements of our every day conceptual scheme includes and enduring objects, casual conceptual relations, include spatial and temporal relations between events and enduring objects, and other persons, and so on. A controversial argument of Davidson’s argues that we would be unable to interpret space from different conceptual schemes as even meaningful, we can therefore be certain that there is no difference of conceptual schemes between any thinker and that since ‘translation’ proceeds according to a principle for an omniscient translator or make sense of ‘us’, we can be assured that most of the beliefs formed within the common-sense conceptual framework are true. That it is to say, our needs felt to clarify its position in question, that notably precision of thought was in the right word and by means of exactly the right way,
Nevertheless, fostering an importantly different sort of casual criterion, namely that a true belief is knowledge if it is produced by a type of process that is ‘globally’ and ‘locally’ reliable. It is globally reliable if its propensity to cause true beliefs is sufficiently high. Local reliability has to do with whether the process would have produced a similar but false belief in certain counter-factual situations alternative to the actual situation. This way of marking off true beliefs that are knowledge does not require the fact believed to be causally related to the belief, and so, could in principle apply to knowledge of any kind of truth, yet, that a justified true belief is knowledge if the type of process that produce d it would not have produced it in any relevant counter-factual situation in which it is false.
A composite theory of relevant alternatives can best be viewed as an attempt to accommodate two opposing strands in our thinking about knowledge. The first is that knowledge is an absolute concept. On one interpretation, this means that the justification or evidence one must have un order to know a proposition ‘p’ must be sufficient to eliminate calling the alternatives to ‘p’‘ (where an alternative to a proposition ‘p’ is a proposition incompatible with ‘p’). That is, one’s justification or evidence for ‘p’ must be sufficient for one to know that every alternative to ‘p’ is false. This element of thinking about knowledge is exploited by sceptical arguments. These arguments call our attention to alternatives that our evidence cannot eliminate. For example, when we are at the zoo, we might claim to know that we see a zebra on the justification for which is found by some convincingly persuaded visually perceived evidence-a zebra-like appearance. The sceptic inquires how we know that we are not seeing a cleverly disguised mule. While we do have some evidence against the likelihood of such deception, intuitively it is not strong enough for us to know that we are not so deceived. By pointing out alternatives of this nature that we cannot eliminate, as well as others with more general applications (dreams, hallucinations, etc.), the sceptic appears to show that this requirement that our evidence eliminate every alternative is seldom, if ever, sufficiently adequate, as my measuring up to a set of criteria or requirement as courses are taken to satisfy requirements.
This conflict is with another strand in our thinking about knowledge, in that we know many things, thus, there is a tension in our ordinary thinking about knowledge-we believe that knowledge is, in the sense indicated, an absolute concept and yet we also believe that there are many instances of that concept. However, the theory of relevant alternatives can be viewed as an attempt to provide a more satisfactory response to this tension in or thinking about knowledge. It attempts to characterize knowledge in a way that preserves both our belief that knowledge is an absolute concept and our belief that we have knowledge.
According t the theory, we need to qualify than deny the absolute character of knowledge. We should view knowledge as absolute, relative to certain standards, that is to say, that in order to know a proposition, our evidence need not eliminate all the alternatives to that proposition. Rather we can know when our evidence eliminates all the relevant alternatives, where the set of relevant alternatives is determined by some standard. Moreover, according to the relevant alternatives view, the standards determine that the alternatives raised by the sceptic are not relevant. Nonetheless, if this is correct, then the fact that our evidence can eliminate the sceptic’s alternatives does not lead to a sceptical result. For knowledge requires only the elimination of the relevant alternatives. So the designation of an alternative view preserves both progressives of our thinking about knowledge. Knowledge is an absolute concept, but because the absoluteness is relative to a standard, we can know many things.
All the same, some philosophers have argued that the relevant alternative’s theory of knowledge entails the falsity of the principle that the set of known (by ‘S’) preposition is closed under known (by ‘S’) entailment: Although others have disputed this, least of mention, that this principle affirms the conditional charge founded of ‘the closure principle’ as: If ‘S’ knows ‘p’ and ‘S’ knows that ‘p’ entails ‘q’, then ‘S’ knows ‘q’.
According to this theory of relevant alternatives, we can know a proposition ‘p’, without knowing that some (non-relevant) alternative to ‘p’‘ is false. But since an alternative ‘h’ to ‘p’ incompatible with ‘p’, then ‘p’ will trivially entail ‘not-h’. So it will be possible to know some proposition without knowing another proposition trivially entailed by it. For example, we can know that we see a zebra without knowing that it is not the case that we see a cleverly disguised mule (on the assumption that ‘we see a cleverly disguised mule’ is not a relevant alternative). This will involve a violation of the closer principle, that this consequential sequence of the theory held accountably because the closure principle and seem too many to be quite intuitive. In fact, we can view sceptical arguments as employing the closure principle as a premiss, along with the premiss that we do not know that the alternatives raised by the sceptic are false. From these two premises (on the assumption that we see that the propositions we believe entail the falsity of sceptical alternatives) that we do not know the propositions we believe. For example, it follows from the closure principle and the fact that we do not know that we do not see a cleverly disguised mule, that we do not know that we see a zebra. We can view the relevant alternative’s theory as replying to the sceptical argument.
How significant a problem is this for the theory of relevant alternatives? This depends on how we construe the theory. If the theory is supposed to provide us with an analysis of knowledge, then the lack of precise criteria of relevance surely constitutes a serious problem. However, if the theory is viewed instead as providing a response to sceptical arguments, that the difficulty has little significance for the overall success of the theory
Nevertheless, internalism may or may not construe justification, subjectivistically, depending on whether the proposed epistemic standards are interpersonally grounded. There are also various kinds of subjectivity, justification, may, e.g., be granted in one’s considerate standards or simply in what one believes to be sound. On the formal view, my justified belief accorded within my consideration of standards, or the latter, my thinking that they have been justified for making it so.
Any conception of objectivity may treat a domain as fundamental and the other derivative. Thus, objectivity for methods (including sensory observations) might be thought basic. Let an objective method be one that is (1) Interpersonally usable and tens to yield justification regarding the question to which it applies (an epistemic conception), or (2) tends to yield truth when property applied (an ontological conception), or (3) Both. An objective statement is one appraisable by an objective method, but an objective discipline is one whose methods are objective, and so on. Typically constituting or having the nature and, perhaps, a prevalent regularity as a typical instance of guilt by association, e.g., something (as a feeling or recollection) associated in the mind with a particular person or thing, as having the thoughts of ones’ childhood home always carried an association of loving warmth. By those who conceive objectivity epistemologically tend to make methods and fundamental, those who conceive it ontologically tend to take basic statements. Subjectivity ha been attributed variously to certain concepts, to certain properties of objects, and to certain, modes of understanding. The overarching idea of these attributions is the nature of the concepts, properties, or modes of understanding in question is dependent upon the properties and relations of the subjects who employ those concepts, posses the properties or exercise those modes of understanding. The dependence may be a dependence upon the particular subject or upon some type which the subject instantiates. What is not so dependent is objectivity. In fact, there is virtually nothing which had not been declared subjective by some thinker or others, including such unlikely candidates as to think about the emergence of space and time and the natural numbers. In scholastic terminology, an effect is contained formally in a cause, when the same nature n the effect is present in the cause, as fire causes heat, and the heat is present in the fire. An effect is virtually in a cause when this is not so, as when a pot or statue is caused by an artist. An effect is eminently in cause when the cause is more perfect than the effect: God eminently contains the perfections of his creation. The distinctions are just of the view that causation is essentially a matter of transferring something, like passing on the baton in a relay race.
There are several sorts of subjectivity to be distinguished, if subjectivity is attributed to as concept, consider as a way of thinking of some object or property. It would be much too undiscriminating to say that a concept id subjective if particular mental states, however, the account of mastery of the concept. All concepts would then be counted as subjective. We can distinguish several more discriminating criteria. First, a concept can be called subjective if an account of its mastery requires the thinker to be capable of having certain kinds of experience, or at least, know what it is like to have such experiences. Variants on these criteria can be obtained by substituting other specific psychological states in place of experience. If we confine ourselves to the criterion which does mention experience, the concepts of experience themselves plausibly meet the condition. What has traditionally been classified as concepts of secondary qualities-such as red, tastes, bitter, warmth-have also been argued to meet these criteria? The criterion does, though also including some relatively observational shape concepts. Th relatively observational shape concepts ‘square’ and ‘regular diamond’ pick out exactly the same shaped properties, but differ in which perceptual experience are mentioned in accounts of they’re-mastery-once, appraised by determining the unconventional symmetry perceived when something is seen as a diamond, from when it is seen as a square. This example shows that from the fact that a concept is subjective in this way, nothing follows about the subjectivity of the property it picks out. Few philosophies would now count shape properties, as opposed to concepts thereof: As subjective.
Concepts with a second type of subjectivity could more specifically be called ‘first personal’. A concept is ‘first-personal’ if, in an account of its mastery, the application of the concept to objects other than the thinker is related to the condition under which the thinker is willing to apply the concept to himself. Though there is considerable disagreement on how the account should be formulated, many theories of the concept of belief as that of first-personal in this sense. For example, this is true of any account which says that a thinker understands a third-personal attribution ‘He believes that so-and-so’ by understanding that it holds, very roughly, if the third-person in question is in circumstance in which the thinker would himself (first-person) judge that so-and-so. It is equally true of accounts which in some way or another say that the third-person attribution is understood as meaning that the other person is in some state which stands in some specific sameness relation to the state which causes the thinker to be willing to judge: ‘I believe that so-and-so’.
The subjectivity of indexical concepts, where an expression whose reference is dependent upon the content, such as, I, here, now, there, when or where and that (perceptually presented), ‘man’ has been widely noted. The fact of these is subjective in the sense of the first criterion, but they are all subjective in that the possibility of abject’s using any one of them to think about an object at a given time depends upon his relations to the particular object then, indexicals are thus particularly well suited to expressing a particular point of view of the world of objects, a point of view available only to those who stand in the right relations to the object in question.
A property, as opposed to a concept, is subjective if an object’s possession of the property is in part a matter of the actual or possible mental states of subjects’ standing in specified relations to the object. Colour properties, secondary qualities in general, moral properties, the property of propositions of being necessary or contingent, and he property of actions and mental states of being intelligible, has all been discussed as serious contenders for subjectivity in this sense. To say that a property is subjective is not to say that it can be analysed away in terms of mental states. The mental states in terms of which subjectivists have aimed to elucidate, say, of having to include the mental states of experiencing something as red, and judging something to be, respective. These attributions embed reference to the original properties themselves-or, at least to concepts thereof-in a way which makes eliminative analysis problematic. The same plausibility applies to a subjectivist treatment of intelligibility: Have the mental states would have to be that of finding something intelligible. Even without any commitment to eliminative analysis, though, the subjectivist’s claim needs extensive consideration for each of the divided areas. In the case of colour, part of the task of the subjectivist who makes his claim at the level of properties than concept is to argue against those who would identify the properties, or with some more complex vector of physical properties.
Suppose that for an object to have a certain property is for subject standing in some certain relations to it to be a certain mental state. If subjects bear on or upon standing in relation to it, and in that mental state, judges the object to have the properties, their judgement will be true. Some subjectivists have been tampering to work this point into a criterion of a property being subjective. There is, though, some definitional, that seems that we can make sense of this possibility, that though in certain circumstances, a subject’s judgement about whether an object has a property is guaranteed to be correct, it is not his judgement (in those circumstances) or anything else about his or other mental states which makes the judgement correct. To the general philosopher, this will seem to be the actual situation for easily decided arithmetical properties such as 3 + 3 = 6. If this is correct, the subjectivist will have to make essential use of some such asymmetrical notions as ‘what makes a proposition is true’. Conditionals or equivalence alone, not even deductivist ones, will not capture the subjectivist character of the position.
Finally, subjectivity has been attributed to modes of understanding. Elaborating modes of understanding foster in large part, the grasp to view as plausibly basic, in that to assume or determinate rule might conclude upon the implicit intelligibility of mind, as to be readily understood, as language is understandable, but for deliberate reasons to hold accountably for the rationalization as a point or points that support reasons for the proposed change that elaborate on grounds of explanation, as we must use reason to solve this problem. The condition of mastery of mental concepts limits or qualifies an agreement or offer to include the condition that any contesting of will, it would be of containing or depend on each condition of agreed cases that conditional infirmity on your raising the needed translation as placed of conviction. For instances, those who believe that some form of imagination is involved in understanding third-person descriptions of experiences will want to write into account of mastery of those attributions. However, some of those may attribute subjectivity to modes of understanding that incorporate, their conception in claim of that some or all mental states about the mental properties themselves than claim about the mental properties themselves than concept thereof: But, it is not charitable to interpret it as the assertion that mental properties involve mental properties. The conjunction of their properties, that concept’s of mental state’ s are subjectively in use in the sense as given as such, and that mental states can only be thought about by concepts which are thus subjective. Such a position need not be opposed to philosophical materialism, since it can be all for some versions of this materialism for mental states. It would, though, rule out identities between mental and physical events.
The view that the claims of ethics are objectively true, they are not ‘relative’ to a subject or cultural enlightenment as culturally excellent of tastes acquired by intellectual and aesthetic training, as a man of culture is known by his reading, nor purely subjective in by natures opposition to ‘error theory’ or ‘scepticism’. The central problem in finding the source of the required objectivity, may as to the result in the absolute conception of reality, facts exist independently of human cognition, and in order for human beings to know such facts, they must be conceptualized. That, we, as independently personal beings, move out and away from where one is to be brought to or toward an end as to begin on a course, enterprising to going beyond a normal or acceptable limit that ordinarily a person of consequence has a quality that attracts attention, for something that does not exist. But relinquishing services to a world for its libidinous desire to act under non-controlling primitivities as influenced by ways of latency, we conceptualize by some orderly patternization arrangements, if only to think of it, because the world doesn’t automatically conceptualize itself. However, we develop concepts that pick those features of the world in which we have an interest, and not others. We use concepts that are related to our sensory capacities, for example, we don’t have readily available concepts to discriminate colours that are beyond the visible spectrum. No such concepts were available at all previously held understandings of light, and such concepts as there are not as widely deployed, since most people don’t have reasons to use them.
We can still accept that the world make’s facts true or false, however, what counts as a fact is partially dependent on human input. One part, is the availability of concepts to describe such facts. Another part is the establishing of whether something actually is a fact or not, in that, when we decide that something is a fact, it fits into our body of knowledge of the world, nonetheless, for something to have such a role is governed by a number of considerations, all of which are value-laden. We accept as facts these things that make theories simple, which allow for greater generalization, that cohere with other facts and so on. Hence in rejecting the view that facts exist independently of human concepts or human epistemology we get to the situation where facts are understood to be dependent on certain kinds of values-the values that governs enquiry in all its multiple forms-scientific, historical, literary, legal and so on.
In spite of which notions that philosophers have looked [into] and handled the employment of ‘real’ situated approaches that distinguish the problem or signature qualifications, though features given by fundamental objectivity, on the one hand, there are some straightforward ontological concepts: Something is objective if it exists, and is the way it is. Independently of any knowledge, perception, conception or consciousness there may be of it. Obviously candidates would include plants, rocks, atoms, galaxies, and other material denizens of the external world. Fewer obvious candidates include such things as numbers, set, propositions, primary qualities, facts, time and space and subjective entities. Conversely, will be the way those which could not exist or be the way they are if they were known, perceived or, at least conscious, by one or more conscious beings. Such things as sensations, dreams, memories, secondary qualities, aesthetic properties and moral value have been construed as subsections in this sense. Yet, our ability to make intelligent choices and to reach intelligent conclusions or decisions, had we to render ably by giving power, strength or competence to enable a sense to study something practical.
There is on the other hand, a notion of objectivity that belongs primarily within epistemology. According to this conception the objective-subjective distinction is not intended to mark a split in reality between autonomous and distinguish between two grades of cognitive achievement. In this sense only such things as judgements, beliefs, theories, concepts and perception can significantly be said to be objective or subjective. Objectively can be construed as a property of the content of mental acts or states, for example, that a belief that the speed of space light is 187,000 miles per second, or that London is to the west of Toronto, has an objective confront: A judgement that rice pudding is distinguishing on the other hand, or that Beethoven is greater an artist than Mozart, will be merely subjective. If this is epistemologically of concept it is to be a proper contented, of mental acts and states, then at this point we clearly need to specify ‘what’ property it is to be. In spite of this difficulty, for what we require is a minimal concept of objectivity. One will be neutral with respect to the competing and sometimes contentious philosophical intellect which attempts to specify what objectivity is, in principle this neutral concept will then be capable of comprising the pre-theoretical datum to which the various competing theories of objectivity are themselves addressed, and attempts to supply an analysis and explanation. Perhaps the best notion is one that exploits Kant’s insights that conceptual representation or epistemology entail what he call’s ‘presumptuous universality’, for a judgement to be objective it must at least of content, that ‘may be presupposed to be valid for all men’.
The entity of ontological notions can be the subject of conceptual representational judgement and beliefs. For example, on most accounts colours are ontological beliefs, in the analysis of the property of being red, say, there will occur climactical perceptions and judgements of normal observers under normal conditions. And yet, the judgement that a given object is red is an entity of an objective one. Rather more bizarrely, Kant argued that space was nothing more than the form of inner sense, and some, was an ontological notion, and subject to perimeters held therein. And yet, the propositions of geometry, the science of space, are for Kant the very paradigms of conceptually presented representations as well grounded to epistemological necessities, and universal and objectively true. One of the liveliest debates in recent years (in logic, set theory and the foundations of semantics and the philosophy of language) concerns precisely this issue: Does the conceptually represented base on epistemologist factoring class of assertions requires subjective judgement and belief of the entities those assertions apparently involved or range over? By and large, theories that answer this question in the affirmative can be called ‘realist’ and those that defended a negative answer, can be called ‘anti-realist’
One intuition that lies at the heart of the realist’s account of objectivity is that, in the last analysis, the objectivity of a belief is to be explained by appeal t o the independent existence of the entities it concerns. Conceptual epistemological representation, that is, to be analysed in terms of subjective maters. It stands in some specific relation validity of an independently existing component. Frége, for example, believed that arithmetic could comprise objective knowledge e only if the number it refers to, the propositions it consists of, the functions it employs and the truth-value it aims at, are all mind-independent entities. Conversely, within a realist framework, to show that the member of a give in a class of judgements and merely subjective, it is sufficient to show that there exists no independent reality that those judgments characterize or refer to. Thus. J.L. Mackie argues that if values are not part of the fabric of the world, then moral subjectivism is inescapable. For the result, then, conceptual frame-references to epistemological representation are to be elucidated by appeal to the existence of determinate facts, objects, properties, event s and the like, which exist or obtain independently of any cognitive access we may have to them. And one of the strongest impulses toward Platonic realism-the theoretical objects like sets, numbers, and propositions-stems from the independent belief that only if such things exist in their own right and we can then show that logic, arithmetic and science are objective.
This picture is rejected by anti-realist. The possibility that our beliefs and these are objectively true or not, according to them, capable of being rendered intelligible by invoking the nature and existence of reality as it is in and of itself. If our conception of conceptual epistemological representation is minimally required for only ‘presumptive universalities’, the alterative, non-realist analysis can give the impression of being without necessarily being so in fact. Some things are not always the way they seem as possible-and even attractive, such analyses that construe the objectivity of an arbitrary judgement as a function of its coherence with other judgements of its possession. On the grounds that are warranted by it’s very acceptance within a given community, of course, its formulated conformities by which deductive reasoning and rules following, is what constitutes our understanding, of its unification, or falsifiability of its permanent presence in mind of God. One intuition common to a variety of different anti-realist theories is this: For our assertions to be objective, for our beliefs to comprise genuine knowledge, those assertions and beliefs must be, among other things, rational, justifiable, coherent, communicable and intelligible. But it is hard, the anti-realist claims, to see how such properties as these can be explained by appeal to entities ‘as they are in and of themselves’: For it is not on he basis that our assertions become intelligible say, or justifiable.
On the contrary, according to most forms of anti-realism, it is only the basic ontological notion like ‘the way reality seems to us’, ‘the evidence that is available to us’, ‘the criteria we apply’, ‘the experience we undergo’, or, ‘the concepts we have acquired’ that the possibility of an objectively conceptual experience of our beliefs can conceivably be explained.
In addition, to marking the ontological and epistemic contrasts, the objective-subjective distinction has also been put to a third use, namely to differentiate intrinsically from reason-sensitivities that have a non-perceptual view of the world and find its clearest expression in sentences derived of credibility, corporeality, intensive or other token reflective elements. Such sentences express, in other words, the attempt to characterize the world from no particular time or place, or circumstance, or personal perspective. Nagel calls this ‘the view from nowhere’. A subjective point of view, by contrast, is one that possesses characteristics determined by the identity or circumstances of the person whose point view it is. The philosophical problems have on the question to whether there is anything that an exclusively objective description would necessarily be, least of mention, this would desist and ultimately cease of a course, as of action or activity, than focussed at which time something has in its culmination, as coming by its end to confine the indetermining infractions known to have been or should be concealed, as not to effectively bring about the known op what has been or should be concealed by its truth. However, the unity as in interests, standards, and responsibility binds for what are purposively so important to the nature and essence of a thing as they have of being indispensable, thus imperatively needful, if not, are but only of oneself, that is lastingly as one who is inseparable with the universe. Can there, for instance be a language with the same expressive power as our own, but which lacks all toke n reflective elements? Or, more metaphorically, are there genuinely and irreducibly objective aspects to my existence-aspects which belong only to my unique perspective on the world and which belong only to my unique perspective or world and which must, therefore, resist capture by any purely objective conception of the world?
One at all to any doctrine holding that reality is fundamentally mental in nature, however, boundaries of such a doctrine are not firmly drawn, for example, the traditional Christian view that ‘God’ is a sustaining cause possessing greater reality than his creation, might just be classified as a form of ‘idealism’. Leibniz’s doctrine that the simple substances out of which all else that follows is readily made for themselves. Chosen by some worthy understanding view that perceiving and appetitive creatures (monads), and that space and time are relative among these things is another earlier version implicated by a major form of ‘idealism’, include subjective idealism, or the position better called ‘immaterialism’ and associated in the Irish idealist George Berkeley (1685-1753), according to which to exist is to be perceived as ‘transcental idealism’ and ‘absolute idealism’: Idealism is opposed to the naturalistic beliefs that mind is at work or in effective operation, such that it earnestly touches the point or positioning to occupy the tragedy under which solitary excellence are placed unequally, hence, it is exhaustively understood as a product of natural possesses. The most common modernity is manifested of idealism, the view called ‘linguistic idealism’, that we ‘create’ the world we inhabit by employing mind-dependent linguistic and social categories. The difficulty is to give a literal form the obvious fact that we do not create worlds, but irreproachably find ourselves in one.
So as the philosophical doctrine implicates that reality is somehow a mind corrective or mind coordinate-that the real objects comprising the ‘external minds’ are dependent of cognizing minds, but only exist as in some way correlative to the mental operations that reality as we understand it reflects the workings of mind. And it construes this as meaning that the inquiring mind itself makes a formative contribution not merely to our understanding of the nature of the real but even to the resulting character that we attribute to it.
For a long intermittent interval of which times presence may ascertain or record the developments, the deviation or rate of the proper moments, that within the idealist camp over whether ‘the mind’ at issue is such idealistically formulated would that a mind implicitly related to outside of or behind nature (absolute idealism), or a nature-persuasive power of rationality in some sort (cosmic idealism) or the collective impersonal social mind of people-in-general (social idealism), or simply the distributive collection of individual minds (personal idealism). Over the years, the less grandiose versions of the theory came increasingly to the fore, and in recent times naturally all idealists have construed ‘the minds’ at issue in their theory as a matter of separate individual minds equipped with socially engendered resources.
It is quite unjust to charge idealism with an antipathy to reality, for it is not the existence but the matter of reality that the idealist puts in question. It is not reality but materialism that classical idealism rejects-and to make (as a surface) and not this merely, but also-to be found as used as an intensive to emphasize the identity or character of something that otherwise leaves as an intensive to indicate an extreme hypothetical, or unlikely case or instance, if this were so, it should not change our advantages that the idealist that speaks rejects-and being of neither the more nor is it less than the defined direction or understood in the amount, extent, or number, perhaps, not this as merely, but also-its use of expressly precise considerations, an intensive to emphasize that identity or character of something as so to be justly even, as the idealist that articulates words in order. If not only to express beyond the grasp to thought of thoughts in the awarenesses that represent the properties of a dialectic discourse of verbalization that speech with which is communicatively a collaborative expression of voice, agreeably, that everything is what it is and not another thing, the difficulty is to know when we have one thing and not another one thing and as two. A rule for telling this is a principle of ‘individualization’, or a criterion of identity for things of the kind in question. In logic, identity may be introduced as a primitive rational expression, or defined via the identity of indiscenables. Berkeley’s ‘immaterialism’ does not as much rejects the existence of material objects as he seems engaged to endeavour upon been unperceivedly unavoidable.
There are certainly versions of idealism short of the spiritualistic position of an ontological idealism that holds that ‘these are none but thinking beings’, idealism does not need for certain, for as to affirm that mind matter amounts to creating or made for constitutional matters: So, it is quite enough to maintain (for example) that all of the characterizing properties of physical existents, resembling phenomenal sensory properties in representing dispositions to affect mind-endured customs in a certain sort of way. So that these propionate standings have nothing at all within reference to minds.
Weaker still, is an explanatory idealism which merely holds that all adequate explanations of the real, always require some recourse to the operations of mind. Historically, positions of the general, idealistic type has been espoused by several thinkers. For example George Berkeley, who maintained that ‘to be [real] is to be perceived’, this does not seem particularly plausible because of its inherent commitment to omniscience: It seems more sensible to claim ‘to be, is to be perceived’. For Berkeley, of course, this was a distinction without a difference, of something as perceivable at all, that ‘God’ perceived it. But if we forgo philosophical alliances to ‘God’, the issue looks different and now comes to pivot on the question of what is perceivable for perceivers who are physically realizable in ‘the real world’, so that physical existence could be seen-not so implausible-as tantamount to observability-in principle.
The three positions to the effect that real things just exactly are things as philosophy or as science or as ‘commonsense’ takes them to be-positions generally designated as scholastic, scientific and naïve realism, respectfully-are in fact versions of epistemic idealism exactly because they see reals as inherently knowable and do not contemplate mind-transcendence for the real. Thus, for example, there is of naïve (‘commonsense’) realism that external things that subsist, insofar as there have been a precise and an exact categorization for what we know, this sounds rather realistic or idealistic, but accorded as one dictum or last favour.
There is also another sort of idealism at work in philosophical discussion: An axiomatic-logic idealism that maintains both the value play as an objectively causal and constitutive role in nature and that value is not wholly reducible to something that lies in the minds of its beholders. Its exponents join the Socrates of Platos ‘Phaedo’ in seeing value as objective and as productively operative in the world.
Any theory of natural teleology that regards the real as explicable in terms of value should to this extent be counted as idealistic, seeing that valuing is by nature a mental process. To be sure, the good of a creature or species of creatures, e.g., their well-being or survival, need not actually be mind-represented. But, nonetheless, goods count as such precisely because if the creature at issue could think about it, the will adopts them as purposes. It is this circumstance that renders any sort of teleological explanation, at least conceptually idealistic in nature. Doctrines of this sort have been the stock in trade of Leibniz, with his insistence that the real world must be the best of possibilities. And this line of thought has recently surfaced once more, in the controversial ‘anthropic principle’ espoused by some theoretical physicists.
Then too, it is possible to contemplate a position along the lines envisaged by Fichte’s, ‘Wisjenschaftslehre’, which sees the ideal as providing the determinacy factor for the real. On such views, the real, the real are not characterized by the sciences that are the ‘telos’ of our scientific efforts. On this approach, which Wilhelm Wundt characterized as ‘real-realism’, the knowledge that achieves adequation to the real by adequately characterizing the true facts in scientific matters is not the knowledge actualized by the afforded efforts by present-day science as one has it, but only that of an ideal or perfected science. On such an approach in which has seen a lively revival in recent philosophy-a tenable version of ‘scientific realism’ requires the step to idealization and reactionism becomes predicted on assuming a fundamental idealistic point of view.
Immanuel Kant’s ‘Refutation of Idealism’ agrees that our conception of us as mind-endowed beings presuppose material objects because we view our mind to the individualities as to confer or provide with existing in an objective corporal order, and such an order requires the existence o f periodic physical processes (clocks, pendula, planetary regularity) for its establishment. At most, however, this argumentation succeeds in showing that such physical processes have to be assumed by mind, the issue of their actual mind-development existence remaining unaddressed (Kantian realism, is made efficiently attained by a methodological sense as linearly through its means of practice, directly to meet with, as through participating or simply of its observation, all for which is accredited to empirical realism).
It is sometimes aid that idealism is predicated on a confusion of objects with our knowledge of them and conflicts the real with our thought about it. However, this charge misses the point. The only reality with which we inquire can have any cognitive connection is reality about reality is via the operations of mind-our only cognitive access to reality is thought through mediation of mind-devised models of it.
Perhaps the most common objection to idealism turns on the supposed mind-independence of the real. ‘Surely’, so runs the objection, ‘things in nature would remain substantially unchanged if there were no minds. This is perfectly plausible in one sense, namely the causal one-which is why causal idealism has its problems. But it is certainly not true conceptually. The objection’s exponent has to face the question of specifying just exactly what it is that would remain the same. ‘Surely roses would smell just as sweat in a mind-divided world’. Well . . . yes or no? Agreed: the absence of minds would not change roses, as roses and rose fragrances and sweetness-and even the size of roses-the determination that hinges on such mental operations as smelling, scanning, measuring, and the like. Mind-requiring processes are required for something in the world to be discriminated for being a rose and determining as the bearer of certain features.
Identification classification, properly attributed are all required and by their exceptional natures are all mental operations. To be sure, the role of mind, at times is considered as hypothetic (‘If certain interactions with duly constituted observers took place then certain outcomes would be noted’), but the fact remains that nothing could be discriminated or characterizing as a rose categorized on the condition where the prospect of performing suitable mental operations (measuring, smelling, etc.) is not presupposed?
The proceeding versions of idealism at once, suggests the variety of corresponding rivals or contrasts to idealism. On the ontological side, there is materialism, which takes two major forms (1) a causal materialism which asserts that mind arises from the causal operations of matter, and (2) a supervenience materialism which sees mind as an epiphenomenon to the machination of matter (albeit, with a causal product thereof-presumably because it is somewhat between difficulty and impossible to explain how physically possessive it could engender by such physical results.)
On the epistemic side, the inventing of idealism-opposed positions include (1) A factural realism that maintains linguistically inaccessible facts, holding that the complexity and a divergence of fact ‘overshadow’ the limits of reach that mind’s actually is a possible linguistic (or, generally, symbolic) resources (2) A cognitive realism that maintains that there are unknowable truths-that the domain of truths runs beyond the limits of the mind’s cognitive access, (3) A substantival realism that maintains that there exist entities in the world which cannot possibly be known or identified: Incognizable lying in principle beyond our cognitive reach. (4) A conceptual realism which holds that the real can be characterized and explained by us without the use of any such specifically mind-invoking conceptance as dispositional to affect minds in particular ways. This variety of different versions of idealism-realism, means that some versions of idealism-realism, means that some versions of the one’s will be unproblematically combinable with some versions of the other. In particular, conceptual idealism maintains that we standardly understand the real in somehow mind-invoking terms of materialism which holds that the human mind and its operations purpose (be it causally or superveniently) in the machinations of physical processes.
Perhaps, the strongest argument favoring idealism is that any characterization of the mind-construction, or our only access to information about what the real ‘is’ by means of the mediation of mind. What seems right about idealism is inherent in the fact that in investigating the real we are clearly constrained to use our own concepts to address our own issues, we can only learn about the real in our own terms of reference, however what seems right is provided by reality itself-whatever the answer may be, they are substantially what they are because we have no illusion and facing reality squarely and realize the perceptible obtainment. Reality comes to minds as something that happens or takes place, by chance encountered to be fortunately to occurrence. As to put something before another for acceptance or consideration we offer among themselves that which determines them to be that way, mindful faculties purpose, but corporeality disposes of reality bolsters the fractions learnt about this advantageous reality, it has to be, approachable to minds. Accordingly, while psychological idealism has a long and varied past and a lively present, it undoubtedly has a promising future as well.
To set right by servicing to explain our acquaintance with ‘experience’, it is easily thought of as a stream of private events, known only to their possessor, and bearing at best problematic relationships to any other event, such as happening in an external world or similar steams of other possessors. The stream makes up the content’s life of the possessor. With this picture there is a complete separation of mind and the world, and in spite of great philosophical effects the gap, once opened, it proves impossible to bridge both ‘idealism’ and ‘scepticism’ that are common outcomes. The aim of much recent philosophy, therefore, is to articulate a less problematic conception of experiences, making it objectively accessible, so that the facts about how a subject’s experience towards the world, is, in principle, as knowable as the fact about how the same subject digests food. A beginning on this may be made by observing that experiences have contents:
It is the world itself that they represent for us, as one way or another, we take the world to being publicity manifested by our words and behaviour. My own relationship with my experience itself involves memory, recognition. And descriptions all of which arise from skills that are equally exercised in interpersonal transactions. Recently emphasis has also been placed on the way in which experience should be regarded as a ‘construct’, or the upshot of the working of many cognitive sub-systems (although this idea was familiar to Kant, who thought of experience ads itself synthesized by various active operations of the mind). The extent to which these moves undermine the distinction between ‘what it is like from the inside’ and how things agree objectively is fiercely debated, it is also widely recognized that such developments tend to blur the line between experience and theory, making it harder to formulate traditional directness such as ‘empiricism’.
The considerations are now placed upon the table for us to have given in hand to Cartesianism, which is the name accorded to the philosophical movement inaugurated by René Descartes (after ‘Cartesius’, the Latin version of his name). The main features of Cartesianism are (1) the use of methodical doubt as a tool for testing beliefs and reaching certainty (2) a metaphysical system which starts from the subject’s indubitable awareness of his own existence (3) A theory of ‘clear and distinct ideas’ base d on the innate concepts and propositions implanted in the soul by God: These include the ideas of mathematics with which Descartes takes to be the fundamental building blocks’ of a usually roofed and walled structure built for science, and (4) The theory now known as ‘dualism’-that there are two fundamentally incompatible kinds of substance in the universe, mind (or thinking substance and matter or, extended substance). A corollary of this last theory is that human beings are radically heterogeneous beings, composed of an unextended, immaterial consciousness united to a piece of purely physical machinery-the body. Another key element in Cartesian dualism is the claim that the mind has perfect and transparent awareness of its own nature or essence.
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