- mind, philosophy of
Branch of philosophy that studies the nature of mind and its various manifestations, including intentionality, sensation and sense perception, feeling and emotion, traits of character and personality, the unconscious, volition, thought, memory, imagination, and belief.It is distinguished from empirical studies of the mind (e.g., psychology, biology, physiology, sociology, and anthropology) by its method, which emphasizes the analysis and clarification of concepts. See also cognitive science.
* * *Introductionreflection on the nature of the mind and of mental acts, including such problems as the relation of the mind to the body, personal identity through time, and the knowledge of other minds.One attribute that sharply distinguishes man (human being) from the rest of nature is his highly developed capacity for thought, feeling, and deliberate action. Here and there in other animals, rudiments, approximations, and limited elements of this capacity may occasionally be found; but the full-blown development that is called a mind is unmatched elsewhere in nature.The task assumed by the discipline known as the philosophy of mind is to examine and analyze those concepts that involve the mind (including the very concept of the mind itself) in an attempt to discover the nature of each of these concepts, the relations between them, how they are to be classified, and how they are to be related to certain other concepts—especially to the concepts of matter and energy, the human body, and, in particular, the central nervous system.It should be clear that the range of topics in the philosophy of mind goes far beyond what is intended in everyday discourse by “mind.” When, for example, the layman speaks of someone as having “a good mind” or as pursuing “the pleasures of the mind,” he is thinking of those particular activities that have to do with abstract reasoning, intellectual pursuits, and the exercise of intelligence. The “mind,” as the term is used more technically in this article and in the philosophy of mind in general today, encompasses a variety of elements including sensation and sense perception, feeling and emotion, dreams, traits of character and personality, the unconscious, and the volitional aspects of human life, as well as the more narrowly intellectual phenomena, such as thought, memory, and belief.Philosophy of mind as a disciplineIn distinguishing the field of philosophy of mind from other sorts of investigation, one immediately obvious feature is its subject matter, the nature of mind and its various manifestations. This serves to distinguish it from empirical sciences such as astronomy and physics, which study matter in motion; from formal disciplines such as geometry and algebra, which study mathematical relationships; and from other fields of philosophy such as the philosophy of art and the philosophy of law. But subject matter alone does not serve to distinguish the philosophy of mind, since the mind is the subject of investigation of other disciplines as well—especially of psychology and of certain phases of biology, physiology, sociology, and anthropology. In comparison with these fields, it is by its method that the philosophy of mind is to be distinguished; for it proceeds not by the methods of empirical investigation—detailed sense observation, the formulation of predictions, the construction of experiments, inductive confirmation, the inventing and testing of contingent generalizations, theories, and laws—but by the method of philosophical reflection. That method consists of the examination of meanings, the analysis and clarification of concepts, the search for necessary truths, the use of deductive inference, reductio ad absurdum, and arguments with infinitely repeating terms and other forms of a priori reasoning, and the attempt to arrive at and evaluate the fundamental principles that underlie and justify the basic forms of human thought and endeavour.Although the philosophy of mind is a distinct field of investigation, it has many important relations with other fields. First, its methods, being those of philosophy in general, are to be tested by the fruits that they have yielded in other areas: if a method has been successful in other areas, it is reasonable to try it here; if unsuccessful in other areas, it is suspect here. Second, the conclusions achieved in such fields as epistemology, metaphysics, logic, ethics, and the philosophy of religion are quite relevant to the philosophy of mind; and its conclusions, in turn, have important implications for those fields. Moreover, this reciprocity applies as well to its relations to such empirical disciplines as neurology, psychology, sociology, and history. Thus, the philosopher of mind must keep informed of developments in all related fields of investigation.The search for a criterion of the mentalThe bewildering variety of phenomena that fall under the heading of the mind or the mental was suggested earlier in a list. The question arises, however, whether there is some attribute that all of these mental phenomena have in common, something that characterizes them or that can serve as a criterion of the mental. More specifically, are there certain features that are either necessary or sufficient for mental phenomena?Purposeful behaviourWhenever a man watches a hungry animal using stealth and cunning in searching out, attacking, and killing its prey, he cannot but believe that the animal has a purpose and uses intelligence in achieving his goal. Whether it be a team of scientists designing a way of launching a man to the Moon, an ape figuring out how to screw two pieces of pipe together to get a banana that is out of reach, or—at a much lower level—a lobster trying to get out of a pot of boiling water, there seems to be a mind at work. Somewhere, as the phenomenon is traced farther down the ladder in the scheme of things toward inanimate matter, a line must eventually be drawn; but there is no agreement about where it should be drawn. It would be widely agreed that an ovum that has just been fertilized does not have a mind and that a normal adult does—but it is impossible to say exactly where in human development the change occurs. On the other hand, it would be just as erroneous to conclude that because there is no sharp dividing line there is no change as it would be to conclude that red and orange are the same colour because no sharp line divides them in the spectrum. In both instances there exists a transitional range within which the designation of a dividing line would be purely arbitrary; but at either end beyond that range a clear and definite difference is evident.The question may then be raised as to how adequate purposeful activity is as a criterion of the mental. A major issue arises from the fact that a mechanical device can be built that exhibits the kind of activity ordinarily called purposeful—a surface-to-air missile, for example, so designed that it will hunt for a jet aircraft by searching for, and zeroing in on, the heat exhaust, thereby finding and destroying the aircraft. Such devices, known as “servomechanisms” (servomechanism) (of which a thermostat is a simple example), achieve an end state by systematically diminishing any deviation from that predetermined end state. There are, in addition, the modern computers, capable of receiving, storing, and retrieving information, of making inferences, and of communicating information. Near the height of modern sophistication in machine technology are those machines, combining servomechanisms and computers, designed to roam the surfaces of other planets, gathering, processing, and sending back data and thus providing what would seem to be paradigms of purposeful behaviour and raising the question whether such systems are examples of minds at work. There are three possibilities worth considering: (1) one might continue to hold that purposeful behaviour is the criterion of the mental but argue that these devices do not really meet the criterion of exhibiting purposeful behaviour; (2) one might hold that the more complex of these devices do indeed have what can be called minds—simple and rudimentary, to be sure, but still minds—“artificial intelligences” (artificial intelligence) that in a very literal sense have beliefs, think thoughts, solve problems, and achieve goals; or (3) one might give up the criterion of purposeful behaviour, or at least give it up as a sufficient condition of the mental.Someone defending possibility (1) would attempt to find some feature of purposeful behaviour that could not be found in any mechanical device. He might hold, for instance, that the alleged purposes of mechanical devices are built in by their designers and that it is not up to the devices to choose their purposes. Against this line of argument, however, others might assert that for a large number of organisms the basic purposes are also built in through the genetic mechanisms of heredity: basic biological drives for food, reproduction, and safety govern most of their purposeful behaviour. People who accept this point of view argue that, in most cases, the organism is not really free to choose its purposes. On this argument, even human beings seem to display such built-in purposes; and it would be specious, at least in this instance, to deny them minds on this account.Conceding that organisms have some built-in controls, the defender of the first possibility might then argue that the higher organisms have a flexibility that allows for the development of purposive methods that are novel. Machines (machine), he would allege, solve problems only by the methods designed into them, whereas creatures with minds can invent new methods. Against this line of argument others might argue that machines have been developed to use trial and error, analyze the outcomes of trends, and come up with new approaches that are more successful than earlier ones, and that, in an important sense, such machines might be called creative, since they “learn from experience” and use “ingenuity.” Many observers assume that this trend in machine technology will continue and that machines will be developed with much, if not all, of the flexibility of many of the creatures that would unhesitatingly be acknowledged to have minds.The basic issue, then, is whether a philosopher would want to say that a machine has a mind if it exhibits the flexibility in purposeful activity of, say, a normal seven-year-old child, who undoubtedly has a mind. In accepting possibility (2), the philosopher would maintain that such a machine does indeed have a mind and exhibits a wide range of the phenomena called mental. Many contemporary philosophers, however, would reject that thesis, considering it a needless flaunting of common sense and an affront to ordinary language to speak of a heat-seeking missile, for example, or even a lunar robot, as having a mind. Because something essential still appears to be omitted, further attempts are made below to determine the essence of the mind.Another characteristic of the mental is sometimes thought to be found in certain ways in which an individual may be said to have something as his object. Thus, thinking, believing, desiring, and other such attitudes are thought to resemble one another in that they may be said to take an object, or to be directed upon an object, in a way quite unlike anything to be found in what is purely physical. “Intentionality” is the term for this way of being directed upon an object. The concept had been emphasized by some of the Scholastics and was introduced to modern philosophy in 1874 by a German philosopher and psychologist, Franz Brentano (Brentano, Franz), and clarified and defended by a U.S. philosopher, Roderick M. Chisholm, in the 20th century.The nature of intentionalityThe idea of intentionality can be explicated in the following way: if one imagines three objects arranged as in Figure 1— and then supposes that the wind blows them so that they are arranged as in Figure 2—>, there results, from the physical point of view, simply a new arrangement. From a psychological point of view, however, something radically new also has been introduced: one object now appears to be pointing to another—aimed at or directed toward it. It would seem that such pointing cannot be accounted for if the observer confines himself to the purely physical facts of the new configuration and that his mind has to be brought in to account for the feature of pointing to. Thus, intentionality is prima facie a reasonable candidate for the criterion of the mental.Intentionality is exhibited in a variety of phenomena. Thus, if a person experiences an emotion toward an object—e.g., loves, fears, pities, envies, or reveres it—he has an intentional attitude toward it. Other examples of intentional attitudes toward an object are: looking for or expecting, believing in, doubting or conjecturing about, daydreaming, reminiscing, imagining, favouring, or disapproving—a list that seems to go on endlessly. Because it clearly comprises so many of the things that one thinks of as typically mental, intentionality, being of broader scope than purposefulness, would seem to be a more appropriate choice than purposeful behaviour for the criterion of the mental.One of the characteristics of intentionality is what the Scholastics called “inexistence”: a man may be intentionally related to an object that does not exist or to an event that does not occur. Thus, what a man looks for may not exist, and an event that he believes to occur may not occur at all. In contrast with such a nonintentional phenomenon as bumping into something, in which the object bumped into must be real, looking for something (an intentional act) does not necessarily imply that the object looked for exists. Similarly, in contrast with an explosion's resulting in the fact that many were hurt, a witness's believing that many were hurt (again an intentional act) does not imply the fact that many were hurt. Thus, existence and truth are irrelevant to intentionality.Though this possible relationship to nonexistent objects as opposed to existent ones is a necessary feature of intentionality, it is not sufficient to define it, for there are phenomena that are equally concerned with nonexistent essences that are nonetheless nonintentional. “That lady resembles a mermaid,” to use an example of Chisholm's, may be a true sentence even if mermaids, though having an essence, do not exist. Similarly, “That metal will ignite at temperatures above 1,000,000°” may be true whether or not such temperatures exist. Thus, intentionality requires further characterization if its scope is to be narrowed to exclude such examples as these.Another characteristic of the intentional state is that not every description of its object will be appropriate. Assuming that his pen is the millionth pen produced this year, for example, a man may be in the intentional state of searching for it as his pen but not in a state of searching for the millionth pen produced this year; similarly, he may believe this is his pen and yet not believe that this is the millionth pen produced this year. This second feature of intentionality, often called “referential opacity,” is such that a true sentence asserting an intentional state will become false when some alternative description of the object of that state is substituted for it (it is false that he is searching for the millionth pen).There is no general agreement on the best way of conceiving of intentional phenomena. Brentano, at one point, thought of intentionality as being a relation between a subject and an entity, in which the entity is something that might or might not exist; but difficulties arise in characterizing the ontological status of such an entity—i.e., its kind of reality. More popular today are certain linguistic approaches: intentionality may be viewed, for example, as it was by Rudolf Carnap (Carnap, Rudolf), a philosopher of science, and others, as a relation between a subject and a piece of language or, as others have explained, as a relation between a subject and a linguistic practice or linguistic role. Under this view, the intentionality consists not in the relation of a subject to an essence (that of a millionth pen) but in its relation to a sentence (“This is the millionth pen . . . ”) that has that alleged essence as its meaning. It remains to be seen whether such approaches will succeed in dealing with all intentional phenomena. It would seem to pose particular difficulty in those cases in which the intentional state is overtly directed toward some existent entity, with language playing a minor or null role, as in situations in which one feels anger, pity, or love toward someone; or when an animal is stalking its prey (which involves an intentional state). In such instances, an analysis in terms of linguistic attitudes would seem wide of the mark.The scope of application of intentionalityThe question of whether or not intentionality can apply to nonliving physical systems has become a controversial issue. If it can apply, then either intentionality would have to be given up as an exclusive criterion of the mental or else one would have to say that such systems exhibit some mental characteristics.It will be useful to consider a system designed for some purpose, taking the example again of the surface-to-air missile that searches for jet aircraft, and to ask whether it has intentionality. It does satisfy the first characteristic mentioned above: that it can be truly said to be a jet searcher regardless of whether there are or have been any jet aircraft (one could similarly design a unicorn searcher built to detect unicorns by their special horn). The question next arises whether some descriptions of the object are inappropriate. On the supposition that all and only jet aircraft have a component made of compound X, one can ask whether it would be true of the missile that it searches for things with a component made of compound X. It would seem that—unless this compound chances to be what the search system was sensitized to—the foregoing statement is a false, and thus an inappropriate, description of the device; and if so, it is plausible to regard the missile as a physical system with intentionality as that notion has been here characterized. An intentional physical system, however, would have to be of considerable complexity. One would not want to say that the left-hand complex in Figure 2—> was pointed to the right-hand figure unless he had in mind that, if the right-hand figure were to shift its location, the left-hand complex would shift appropriately. If it did keep shifting appropriately, however, it would seem proper to say that it points to the right-hand figure. The question remains, however, whether all intentional phenomena are capable of appearing as instances in nonliving physical systems—whether such a physical system could have, for example, an emotion toward something, daydream about something, or be amused by something. Here it is very difficult to cite a plausible case; it would appear that one would have to strain such concepts considerably to apply them to nonliving systems.The thesis that intentional phenomena are the essence of the mental thus seems problematic. Its suggestion that the jet-searching missile has a mind or partakes of the mental, as appeared in the discussion of the criterion of purposeful behaviour, would, to many scholars, appear to be quite implausible. Nor does it seem that the trouble lies in the limited number of intentional phenomena found in the missile. Even the lunar-exploration machines, with all of their flexibility and multiplicity of functions, would not be said by most analysts to have minds.It might be possible to save intentionality as the criterion of the mental by insisting on the presence of such highly sophisticated intentional phenomena as emotions, daydreams, or amusement, but then one would have to deny minds to those human beings who lack a sense of humour, never daydream, or are cold-bloodedly unemotional, which does not seem correct either. Some progress can be made here if the question is asked whether intentionality is a necessary condition of all mental phenomena—whether there are any phenomena that are mental but nonintentional. Examples of a mental phenomenon that can most plausibly be said to be nonintentional are sensations, such as feeling pain, which lack both of the aforementioned characteristics of intentionality—inexistence and referential opacity. A man cannot feel a pain that, unbeknownst to him, does not exist; if he feels pain, there must be something he feels. Moreover, if a man feels pain, and the pain is identified with the effect of a tumour, then he does feel the effect of the tumour.Sensations, which thus lack both of the characteristics of intentional phenomena, are not just an odd counterexample; not only do sensations comprise a large and central group of mental phenomena, but they also call attention to an important aspect of many other mental phenomena, viz., subjective experience. The arrow in Figure 2—> may point to the circle, but it does not have the subjective experience of pointing, it does not feel itself pointing; and the jet-searching missile does not experience how it feels to be searching for jets. But when a person is in an intentional state, directed toward an object, he—at least sometimes—experiences, feels, or is aware of that directedness.Clearly, this usage of “intentionality” differs somewhat from that found in medieval philosophy; and there are other features of the concept, not covered here, that are stressed by Phenomenologists and Existentialists.Subjective experienceIt is often maintained that the essence of the mental consists of states of consciousness taken as subjective experiences. When a person wakes up or regains consciousness after a general anesthetic, a host of experiences of colour and light, sounds, feelings, thoughts, and memories flood in on him. As far as his objective, observable behaviour is concerned, he may be lying unmoved and unmoving; but as far as his state of consciousness is concerned, he may be undergoing a series of subjective experiences. To take an example, when a person sees a scarlet patch, he experiences the homogeneous, spread-out, distinctive scarletness present before him. A blind or colour-blind person who has never experienced scarlet would not have the awareness of scarlet that the normally-sighted person has. He might have some vague idea, as did the hero of the story told by John Locke (Locke, John), a 17th-century British Empiricist:A studious blind man, who had mightily beat his head about visible objects, and made use of the explication of his books and friends, to understand those names of light and colours which often came in his way, bragged one day, that he now understood what scarlet signified. Upon which his friend demanding, what scarlet was? the blind man answered, It was like the sound of a trumpet.This reply is not totally wide of the mark; but any sighted person will have a far more precise idea of scarlet than that. What he has and what the blind person lacks is something that philosophers have called the “raw feel” of scarlet, that peculiar and special way scarlet looks.The subjective experience of scarlet is to be contrasted with the discrimination of scarlet things. One could imagine a blind person who was able to discriminate scarlet from other colours by the use of optical instruments (e.g., spectroscopes with Braille printouts). But he would lack the subjective experience of the colour; he would not know the look of scarlet. Defenders of this view would claim that there is a great variety of subjective experiences and that the experience of colours is only one of them. Sensations (e.g., the experiences of pain, tickles, throbbings, pangs, nausea, and tiredness) provide another such example. Still other subjective experiences include: the experiencing of images (afterimages, memory images, and others); feelings of exultation, depression, pride, anger, fear, and love; and thoughts (imaginings, surmisings, doubtings, and recollectings). All of these are episodes, occurring at a particular time and place, in which the subject is in a state of awareness that has a particular content.Adequacy as a criterion of the mentalThe question now arises of how adequate subjective experience is as a criterion of the mental—whether, though it is obviously a sufficient condition for something to be mental, it is a sufficient condition for something to have a mind. The Scotsman David Hume (Hume, David), an 18th-century philosophical Skeptic and historian, once asked whether a creature that had but one state of consciousness could be said to have a mind and concluded that it could not. In his view, it takes, at the very least, a number of states of consciousness linked by memory before one would say that the creature has a mind; and it may be that there has to be a certain level of complexity in the nature and relation of the conscious states for there to be a mind.It is doubtful, however, whether consciousness is a necessary condition for the mental. Before Sigmund Freud (Freud, Sigmund), it would have been widely agreed that the notion of unconscious mental phenomena was logically impossible—a contradiction in the very terms. That view had one important exception, however: Gottfried Wilhelm Leibniz (Leibniz, Gottfried Wilhelm), a 17th-century Rationalist and mathematician, held that there are petites perceptions of which the subject is unconscious. They are so slight, so similar to others, so familiar, or in such a crowd of other perceptions, that the subject is unaware of them at the time. One of the examples that Leibniz cited is the person who is unaware of the roar of the waterfall or the rumble of the mill if he has lived nearby for some time. Leibniz seemed to have had in mind what modern psychologists call “subliminal” perceptions, viz., those below the threshold of awareness but still capable of leaving some effects on the mind. But Leibniz confined unconscious states to perceptions; he would not have allowed unconscious beliefs, desires, emotions, or judgments.It was Freud's great contribution to have discovered a range of phenomena of which the patient was unconscious but which were very much like typically mental phenomena, especially in their behavioral manifestations. In the light of such similarities, it was plausible to extend the concept of the mental to include these unconscious phenomena—especially since they were such that the patient could become conscious of them through hypnosis or psychotherapy. Freud postulated a mechanism that he called “repression” to explain why the patient is unconscious of them.In addition to the subliminal and the unconscious, there are more familiar characteristically mental phenomena that do not consist of states of consciousness. When a man falls into a dreamless sleep, he does not lose all his beliefs or abandon all his goals, he does not cease wanting a better world or being artistic or imaginative or lazy, nor does he forget how to do arithmetic or speak French. A person is not jealous of someone only when thinking of him, nor does a businessman have confidence in the dollar only when concentrating on business. Obviously, these mentalistic characteristics can apply in a dispositional way to people who are not at that moment expressing or exhibiting the disposition.Furthermore, as Gilbert Ryle (Ryle, Gilbert) has pointed out in great detail, a person may use his mind on many occasions without the feeling of subjective experiences. As he says,When we describe people as exercising qualities of mind, we are not referring to occult episodes of which their overt acts and utterances are effects; we are referring to those overt acts and utterances themselves. (This and the following quotations attributed to Ryle are from The Concept of Mind by Gilbert Ryle. Copyright © 1949 by Gilbert Ryle. Reprinted by permission of Barnes & Noble, Publishers, New York, Hutchinson Publishing Group Ltd., London.)To be responsive to one's surroundings, to act intelligently, deliberately, with wit or good grace, to utilize arithmetic or logic, to be sympathetic or coldhearted, to drive alertly or absentmindedly—none of these requires the occurrence of subjective experiences or inner states of consciousness, the immediacy of feelings or sensations. In such activity, there may be nothing going on except performances of a particular kind, and there may be nothing more required except that under further circumstances other performances of a particular kind will be forthcoming. It is, thus, reasonable to conclude that subjective experience is not a necessary condition for the mental.Those who have put the private events of subjective experience at the centre of the mental have committed what Ryle calls a “category-mistake . . . represent[ing] the facts of mental life as if they belonged to one logical type or category, . . . when they actually belong to another.” The mistake consists of taking talk about a person's mind as talk of events in a world parallel to the ordinary world but occult and mysterious. The truth, according to Ryle, is thatto talk of a person's mind . . . is to talk of the person's abilities, liabilities and inclinations to do and undergo certain sorts of things, and of the doing and undergoing of these things in the ordinary world.It would be rash, however, to draw the further conclusion that subjective experiences are in no way involved in whatever is mental. Returning to the case of Leibniz' petites perceptions that are not experienced, a person can be conscious of them in various ways, either before getting used to them or when they are alone or when their intensity or his own sensitivity is increased; and Freud's unconscious phenomena can become conscious phenomena under favourable conditions. The beliefs that an individual is not aware of in sleep are sometimes the objects of his consciousness, as are his moments of laziness and imaginativeness, his knowledge of arithmetic, and his goals. It is dubious that something that has no connection with states of consciousness could qualify as mental.Core characteristics of subjectivityPhilosophers deeply disagree on how to characterize what is peculiar to subjective experiences. Some hold that the existence of subjective experience indicates that there are peculiar events that do not occur in the public space–time world that everyone shares and has equal access to but occur only in a private world that each person has exclusively to himself, which he cannot share with others, and to which no one else has access. Ryle has called this view, with what he admits to be “deliberate abusiveness,” “the dogma of the Ghost in the Machine.” He characterizes the dogma as follows:Minds are not in space, nor are their operations subject to mechanical laws. The workings of one mind are not witnessable by other observers; its career is private. Only I can take direct cognisance of the states and processes of my own mind. A person therefore lives through two collateral histories, one consisting of what happens in and to his body, the other consisting of what happens in and to his mind. The first is public, the second private. The events in the first history are events in the physical world, those in the second are events in the mental world.Are there private events? Even so adamant a critic of privacy as Ryle admits the existence of some private phenomena, chiefly dreams and daydreams, sensations, thoughts, and imaginings. He insists, however, thatthe sequence of your sensations and imaginings is not the sole field in which your wits and character are shown; perhaps only for lunatics is it more than a small corner of that field.In Ryle's view, private events occupy a small and inessential place in the total range of mental phenomena; but they do occur.The notion of privacy is really the conflation of two ideas: the metaphysical idea that mental events do not occur in space and the epistemological idea that mental events are objects of awareness solely to the person who is subject to them. Each of these may be considered in turn.The Rationalist René Descartes (Descartes, René), the earliest major philosopher of modern times, held that the essence of all that is nonmental consists in being extended in space. Turning this around and broadening it, one could say that the essence of the mental consists in the lack of spatiality; i.e., the lack of shape, size, and, above all, location. If the philosopher confined himself to events, he would say that necessarily a physical event occurs in some place or other, but, necessarily, a mental event does not. It would be conceded that the person who experiences the mental event does typically have a location, and this leads to the question of why the event is not located where the person is located.A defender of the nonspatiality criterion would argue that such ascriptions of location to mental events are very different from ascriptions of location for physical events. For a physical event, it is always possible to ask whether it occurred at some point, in some part, or throughout the location. Thus, if the temperature of a body of water rises, one can ask precisely where the rise occurred—at certain points, in certain parts, or throughout the volume. But if a thought occurs, it is senseless to ask whether it occurred throughout the area or only in some part of it. Furthermore, if the water undergoing the rise in temperature is in a box, it is reasonable to say that a rise in temperature occurred in the box; but if the person having a thought is in a box, it is senseless to say that a thought occurred in the box. So the sort of ascription of location is quite different for mental events, and the criterion can still be used to mark off the mental from the physical.The question remains whether the sort of nonspatiality that is allegedly appropriate to the mental is peculiar to it. If such a physical event as recovering from an illness or changing shape is considered, it would appear also that it does not make sense to ask whether the event occurred throughout the whole volume, in some part, or at some point. Thus, it would seem that even this modified notion of spatiality does not uniquely distinguish the mental.Privileged status of subjectivityOther philosophers would interpret subjective experiences not as private events but as a special way of knowing certain events, specifically by introspection. This is called the “privileged access” view. John Locke, contrasting this way of knowing with sensation, called it “reflection,” defining it as “that notice which the mind takes of its own operations and the manner of them.” It is a way of being aware of one's own present states without the intervention or use of the senses. The emphasis here is on the way of knowing rather than on the events known. Someone who holds the privacy view will have to hold that there is some special way of knowing these special events, but someone who holds the privileged access view is not necessarily committed to holding that the events so known are in any way special. A person could hold that one and the same event can be known both by sense perception and in some other way. Being knowable by introspection would then be the characteristic that defines events as mental. Such an account, however, would not rule out that they may also be knowable by sense perception or by inference.Some contemporary philosophers deny that there is any such special way of knowing. Ryle offers three objections: first, it would require that there be simultaneously multiple attentions—in the mental event itself and in the attending to that event; though it is not denied that such divisions of attention are possible, he suggests that they are more unusual and difficult to achieve than the proponent of introspection would have the reader believe; second, because there is obviously some upper limit to the number of simultaneous attendings that a person is capable of, there will have to be some mental acts of which a person is unaware, and if it is admitted that some mental events occur without being known in this special way, it is fair to ask whether one must assume that any of them are known that way; finally, for many states of mind—e.g., extreme panic or fury—the person is so involved that he is incapable of taking note of them, yet such states are not, in consequence, suspect—the person involved is as sure that they occur as he is of any so-called mental events. There is thus no need to postulate this special way of knowing to account for man's knowledge of any such events.It is not clear how compelling Ryle's objections are. It is admitted that attention can be divided, though it may be contended that it is unusual and difficult to achieve this division. Others would reply that it is a lot more common and easier than might be thought, that it occurs whenever a man takes note of his mental states. And from the fact that he cannot take note at the same time of very many of his mental states, it hardly follows that he never does; each could still be introspectable even if it was not actually introspected on that occasion. As for Ryle's third objection, it might be that some states of mind cannot be introspected, but it does not follow that none can be introspected; they might still be private for all that. Ryle, for instance, while denying introspection, admits retrospection, a capacity to recall one's states just after they occur. It would seem, however, that there is no important difference between a concurrent “introspection” and a prompt “retrospection.” One advantage of retrospection is that it would explain an individual's self-knowledge of those events that are difficult to explain in terms of introspection; e.g., extreme panic or fury.Whether a person introspects or retrospects (the truth appears to be that sometimes he does the one, sometimes the other), he would still seem to have a kind of knowledge about his own present and recently past mental states that he does not have of the mental states of others and that others do not have of his. It is not possible either to introspect or to retrospect the mental states of others; the knowledge that a man has of the present and immediately past mental states of others must be based upon perceptions or inferences from perceptions, whereas the knowledge that he has of his own present and immediately past mental states need not be, and usually is not, so based.It is possible that the notion of introspection can thus be used to define the mental. Such a definition would be of the form: a mental event is an inner event that can be introspected. The difficulty remains, however, of how “introspected” is to be defined. If it is defined merely as “known without inference or sense perception,” then it would seem to apply equally to the knowledge of certain bodily events that no one would want to call mental. An individual can know without sense perception, for example, that his heart is beating rapidly or that his fingers are crossed. To rule such cases out, one can include among the senses the kinesthetic sense that utilizes nerve endings within the body—those, for instance, that register the conditions of one's own muscles. But then it might appear that one must say that sensations are not mental phenomena, since the awareness of them typically involves such nerve endings. Such an admission, however, would be fatal for the privileged access view because sensations are precisely the sort of thing to which a person is supposed to have privileged access. If, on the other hand, the philosopher makes it a matter of definition that introspection applies only to the mental, then he cannot define the mental in terms of introspection. Thus, philosophers are at the present time faced with serious and unsolved difficulties in using the notion of introspection to define the mental.Finally, it is significant here, as it was in the discussion of subjective experience, that to much of man's mental life and to many of the exercises of his mind—e.g., employments of intelligence—he has no special privileged access; there are, in addition, the unconscious phenomena that are not introspectable. So introspection cannot be a necessary condition of the mental.A clue to a more satisfactory criterion of the mental can be found in the attack on introspection cited above. There the difficulty was noted that there does not seem to be a way of distinguishing how an individual knows his mental state from how he knows such inner physical states as the rapid beating of his heart. But it may be argued that there does seem to be a difference between these two ways of knowing: specifically, it is clear how a person could be shown that he was mistaken in believing that his heart was beating rapidly; but it is by no means clear what would show a person that he was mistaken in believing himself to be feeling a particular throbbing, pounding sensation. For mental events, the subject's own beliefs are peculiarly authoritative. This authority only holds, of course, for present mental events; it is clear that many things could show that a person's belief about a past mental event of his was mistaken. It is sometimes claimed that what distinguishes mental events is their so-called indubitability—the fact that a belief by the subject that the event is occurring cannot be false or in error. However, the view that first-person, present-tense reports of mental events are indubitable has come under serious attack; to make such a report is to classify, and it is argued that it is always possible to err in classification.Instead of holding that such beliefs are indubitable, it is often more modestly maintained merely that such beliefs are “incorrigible,” meaning that nothing will count as overthrowing (or correcting) such beliefs. A person who believes that he is experiencing a throbbing sensation may be mistaken; but there is nothing that will show an observer or him that he is mistaken, nothing that will entitle either of them to believe that he is mistaken. He may be experiencing a throbbing sensation even when no part of his body is actually throbbing, though the explanation for this curious fact might not be known.It might be objected against the incorrigibility thesis that the same difficulty that arises for the alleged indubitability of first-person, present-tense beliefs about mental events also arises for their alleged incorrigibility. For if misclassification is possible, it would also seem possible to gather evidence that someone is misclassifying. If one could confuse a throbbing sensation with a different but somewhat similar sensation, it is reasonable to believe that this confusion could be known by others to have occurred. Perhaps the best that can be said for the incorrigibility thesis is that there is always a strong presumption that such beliefs are true, though this presumption can sometimes prove to be unwarranted. But then it is by no means clear that privileged authority is a unique criterion that distinguishes mental events, for such a presumption would also hold for many nonmental events as well (e.g., the belief that one's heart is beating rapidly). Yet if the degree of presumptive force is taken into account, it is reasonable to say that it would be comparatively harder to overthrow beliefs about one's present mental events; and perhaps this is all that one needs to give the criterion force.The existence and status of the mindThe basic metaphysical issues in the philosophy of mind concern whether the mind exists and, if it does, what kind of existence it has and what its relation is to the rest of what exists. Materialists (Materialism) hold that only physical matter (and physical energy) exists. For those who hold, on the other hand, that the mind exists as an immaterial entity, there are dualistic theories for which both immaterial minds and material bodies exist, and immaterialistic theories for which only minds exist but not bodies. There are, finally, the so-called neutral monist theories for which the fundamental existents in nature are neither mental nor physical but some neutral stuff out of which both the mental and the material are formed.The mind as materialThe basic contention of Materialism is that nothing exists but matter and its purely material properties, so that the concepts that are necessary and sufficient for describing and explaining matter will be necessary and sufficient for describing everything that exists. This view can be found in the early Greek philosophers. Thales of Miletus, who lived some 2,500 years ago (6th century BC) and who is generally regarded as the first philosopher in the Western tradition, is supposed to have held that all things are composed of water in some form or other; later thinkers added air, fire, and earth to the list of fundamental elements. The philosopher Anaxagoras of Clazomenae (Anaxagoras), born about 500 BC, introduced a new factor, Nous (Mind), which arranged all other things in their proper order, started them in motion, and continues to control them. There is still controversy as to how his concept of Mind is to be understood, but since he spoke of Mind as being “the finest and purest of all things” and as occupying space, it is likely that he did not think of it, as some later thinkers did, as nonmaterial stuff but rather as a very special kind of material stuff.It was with the Atomists (atomism), Leucippus of Miletus (Leucippus) and his disciple Democritus of Abdera (Democritus), in the 5th and early 4th centuries BC, that Materialism was given its most developed statement. According to them, nature consists solely of an infinite number of indivisible particles, having shape, size, and impenetrability, and no further properties, and moving through an otherwise empty space. The shape, size, location, and movement of these particles make up literally all of the qualities, relations, and other features of the natural world. Such phenomena as sensations, images, sense perceptions, and thought—of particular interest to the philosophy of mind—are explicitly held to consist in the various qualities and relations of the particles.Contemporary Materialists would, no doubt, wish to incorporate into their theory the latest findings of the physical sciences—the convertibility of matter and energy, the wave–particle duality, and the various subatomic particles and antiparticles with their peculiar properties, including the conservation of charge, direction of spin, and direction of time—but these would represent mere changes in detail. In broad outline, the theory would be the same.Given the theory of Materialism in such broad outline, however, a serious question remains concerning the actual account to be given of such phenomena as sensations, images, perceptions, emotions, memories and expectations, desires, beliefs, thoughts, imaginings, and intentions. Among the possible views are those called eliminative Materialism, Behaviourism, and the central-state theory.Eliminative MaterialismA philosopher might hold that there are no such things as sensations, images, perceptions, or emotions and that there never have been such. From this view, those who have believed in the existence of such things have simply been mistaken. A person might hold this view, called eliminative Materialism, on the grounds that all talk of such supposed phenomena is (1) meaningless verbiage, or (2) part of a set of theories that are outmoded, scientifically fruitless, and to be discarded, like theories about witches or the Homeric gods. On either account, it is implied that all such terms should be eliminated from the philosopher's vocabulary. There is a further doctrine, however, to the effect that all such talk is (3) meaningful but nondescriptive and without truth value. On this account, the proper function of such language is not to state facts but might be to prescribe or evaluate.Among Materialistic views, the alternative to eliminative Materialism is some kind of reductive Materialism (identity theory). According to this view, there are indeed such things as sensations, images, perceptions, and emotions, but they are only complicated forms of matter in motion. The philosopher may thus continue to use terms referring to such things (in contrast with eliminative Materialism), but he should keep in mind that no extra entities or features are being postulated over and above the physical entities with their physical features.If one asks reductive Materialists what sensations, images, and the like are, one will find that two alternatives have been proposed. The first is Behaviourism, the view that all such terms refer to the behaviour or movements of certain bodies, particularly of the higher animals. Thus, the Behaviourist would claim that to feel pain is to groan, writhe, blanch, moan, and so on, or at least to be disposed or tend toward such behaviour; to desire food is to engage in eating in the presence of food, in hunting in the absence of food, and so on, or at least to be disposed or tend toward such behaviour; and so also with all of the states and activities that one thinks of as mental.Usually, Behaviourism is intended as a logical doctrine to the effect that the very meanings of the words referring to the mind, its mental states and activities, are to be analyzed in behavioral terms, that every mentalistic term is synonymous in meaning with some behavioral term. It is important to distinguish this view, logical Behaviourism, from the view of many psychologists that the most fruitful way to study psychological phenomena is to study human and animal behaviour. Such a view might be called methodological Behaviourism because it is actually the proposal that the science of psychology restrict itself to certain methods. It does not entail logical Behaviourism. Logical Behaviourism might also be distinguished from the view that psychological and behavioral terms, though not synonymous in meaning, have, as a matter of fact, the same denotation or reference, a view that might be called de facto Behaviourism.Central-state theory (identity theory)The second type of reductive Materialism is the central-state theory. In this view, mental states and activities are identical with states and activities within the body (hence this theory is sometimes called the identity thesis). In particular, they are identical with states and activities of the central nervous system or brain. Thus, to feel pain is for the brain to be in a particular state; to desire food is for the brain to be in another state.Distinctions parallel to those for Behaviourism can be made for the central-state theory. A psychologist might hold that the only useful way of studying psychological phenomena is to study the central nervous system; this view might then be called methodological central-statism. A philosopher might hold that the very terms referring to the mind, its mental states and activities, are synonymous with neurological terms (or, more plausibly, that they should be taken to be synonymous—they obviously are not synonymous as language now stands). This position, which could be called logical central-statism, would differ from the eliminative Materialism mentioned above in that it would retain mentalistic terms rather than eliminate them but would redefine them neurologically. If this came to pass, such terms might eventually disappear, a result that eliminative Materialism would strive to achieve more directly.The mind as immaterialPlato was the first important figure in the Western tradition explicitly to defend the doctrine that the mind is an entirely nonmaterial entity—without such defining material properties as size, shape, or impenetrability—separate and distinct from the human body and able to exist apart from it. Plato used the Greek word psychē (traditionally translated as “soul”).Plato held that the mind (psychē) was in charge of the body and directed its movements. In his dialogue the Phaedrus, Plato spoke of the mind as having both appetitive desires and the higher desires and as having, in addition, a rational capacity to control, direct, and adjudicate between the two. This rational capacity of mind is the most valuable aspect of man, the part most worthy to be nurtured and developed, and the aspect of man most likely to be immortal (much of the dialogue concerning the last hours of Socrates, the Phaedo, is about these topics).Plato was a dualist; he believed in the existence of both material entities and immaterial ones. The most explicit statement of dualism, however, is found in the writing of René Descartes (Descartes, René), who argued that mind and matter are two separate and distinct sorts of substances, absolutely opposed in their natures, each capable of existing entirely independently of the other.The dualist is faced with the question of how, if at all, mind and matter are related to each other. Most dualists would agree that in rocks, tables, and other material things, matter exists alone and unrelated to mind; and that at what is called death (since for Descartes the soul is immortal), immaterial minds exist unrelated to matter. In the case of a living human being, however, there are two substances: a mind and a body. Thus, the question arises of how the relation between them is to be conceived. Any dualistic theory would have to account for certain obvious facts about human beings. When people's bodies are affected in certain ways—when subjected, for example, to bright lights, loud noises, rises in temperature—people often experience colours, sounds, or sensations of warmth or of pain. Again, when people experience certain things, their bodies undergo certain changes—they shut their eyes, they put their hands to their ears, they perspire, or their faces become pale.There are various ways that dualists have proposed to account for these facts. The most straightforward position is interactionism, the view (held by Descartes) that mind and body are capable of affecting each other causally, so that what happens in the body can produce effects in the mind and vice versa. Descartes decided that somewhere within the nerve tissues of the brain was the place where the interactions occurred and chose the pineal gland as the precise point because of its central location. (It is now known that the pineal gland cannot perform the functions that Descartes attributed to it, though its precise functions are still unknown.)It is an implication of interactionism that there cannot be a complete explanation of brain functioning exclusively in terms of the laws of neurology because of the intervention at crucial moments of the influences of the mind. This limitation has struck many scholars as an important difficulty. One way around it is epiphenomenalism, the view that the body can affect the mind but that the mind cannot affect the body. Mental events are mere by-products of brain activity, like the exhaust from an engine or the shadows cast by moving figures. When the mind would appear to be affecting the body, as when the experience of pain seems to cause one to grimace, the epiphenomenalist hypothesizes that the very brain state that produces the experience of pain also produces the grimace.Dualists of either the interactionist or epiphenomenalist persuasion are committed to the existence of causal relations between body and mind. Some philosophers, struck by how entirely different mind and matter are supposed to be on the dualist hypothesis, have held it to be impossible that they could affect each other. psychophysical parallelism avoids this difficulty by postulating that mind and body are like two perfect clocks, each with its own mechanism but in constant and uniform correlation with the other. Unfortunately, the analogy does not hold very well, for the mind does not seem to have the kind of internal mechanism that would account for any precise sequence of its successive states, and without such a mechanism it would be implausible to expect a constant but noncausal correlation between those states and states of the body.Some philosophers have held the doctrine of immaterialism, so named by Bishop George Berkeley (Berkeley, George), one of the classic British Empiricists, in whose view everything that exists is mental, of “the stuff that dreams are made on,” and there is no such thing as the material. There are two major alternatives here: that reality consists of one vast, all-encompassing mind, or that it consists of a plurality of minds. The former position is sometimes called absolute Idealism; the latter, which Berkeley himself held, is sometimes called subjective idealism.The philosophy of Berkeley represents a highly developed and energetically defended statement of the position that reality consists wholly of minds, the divine Mind and the multiplicity of finite minds that includes all men. Whatever exists does so either because it is a mind or because it is dependent upon a mind; nothing material exists. Berkeley argued that the notion of the material should play no role in one's thinking, for its existence is unverifiable, its postulation unnecessary, and, at bottom, the very notion is self-contradictory. How does Berkeley view the status of tables and chairs, rocks, the Moon, and all of the other apparently material things that everyone accepts as existing? Berkeley agreed that they do indeed exist but only as collections of ideas that exist in the mind of God and that are often caused by God to exist in the minds of men as well.There are well-known difficulties in Berkeley's view. His account of the nature of tables and other objects cannot be accepted as an account of the meanings of these terms because it is implausible to think that the concept of a divine Mind is somehow part of their meaning. Nor does it seem a plausible scientific theory about such objects because of its ad hoc character and its lack of predictive value. If the notion of God is dropped, however, the philosopher is left with the phenomenalistic theory (phenomenalism) that such objects are collections of appearances. But phenomenalism also has serious difficulties; in particular, it cannot in the end account for the difference between real objects and illusions because it cannot provide an account of the difference between circumstances in which perceptions are veridical and those in which they are not.The other variety of immaterialism, called Absolute Idealism, derives from certain doctrines of Immanuel Kant and of the classical German Idealists who followed him—Johann Fichte, Friedrich Schelling, and G.W.F. Hegel—concerning the fundamental dependence of reality on mind or spirit in general. Among the several philosophers who have defended this view, there was, at the turn of the 20th century, F.H. Bradley (Bradley, F H), whose Appearance and Reality (1893; 2nd edition 1897) comprises its most systematic exposition and defense. Bradley denied that a plurality of minds exists and insisted that there is only one infinite Mind, Idea, or Experience that comprehends all of existence within it.Neutral theories (neutral monism)Another important view has been that neither the mental nor the physical is really fundamental; each is an aspect of some underlying reality that is neither mental nor physical but neutral between them. There are many variants of such a view. Spinoza (Spinoza, Benedict de), a 17th-century Rationalist, held that the underlying substance, which encompassed all of reality and which he called God or Nature, had both thinking (the mental) and extension (the material) as attributes. A modern version of this position is that of Peter Strawson (Strawson, Sir Peter), a leading philosopher of the Oxford “ordinary language” school, who differs from Spinoza in holding that there is a multiplicity of substances, some of which are purely material and some of which are persons (thus he is not really a monist). Strawson conceives of persons as substances whose nature is to have both mental and physical attributes. Thus, one and the same substance can have both qualities, and the difference between the mental and the physical is conceived as a basic difference between the qualities.A different approach was suggested in some of Hume's (Hume, David) writings and diversely stated by the Pragmatist William James and by various Positivists (Ernst Mach, Rudolf Carnap, and A.J. Ayer). They postulate a number of particular entities, experiences, that go to make up minds when they are related in certain ways, as by the laws of association and memory, and that go to make up bodies when the entities are related in other ways, as by the laws of perspective. Thus, a person's mind is conceived to be just the collection of his experiences, whereas a physical object is conceived to be just the collection of experiences that people can have of it. Here the difference between the mental and physical consists in the different kinds of relations obtaining between the neutral particulars, experiences.Recently, it has been suggested by certain Linguistic philosophers (analytic philosophy) that the difference between mind and body lies in two different kinds of language or conceptual systems: the physicalistic-conceptual language, on the one hand, with its spatiotemporal terms, and person-talk, on the other, with its reference to norms for assessing the rationality, moral responsibility, and ethical value of human actions.Existentialist (Existentialism) and Phenomenological philosophers (Phenomenology) have expressed similar conclusions, supported not so much by linguistic considerations as by general observations of man's condition as a being in the world, with a body, which he experiences and which, by its nature, affects his experience. Man can be viewed as a spatiotemporal aggregate, an object for observation, study, and manipulation, an instance of the laws of nature. But man can also be viewed as a self-moved mover, a being who alters himself and the world through the decisions he makes, who determines values and invests things with those values, who can make his life and his world according to the values that he determines, and who, in the end, can negate his values and even terminate his life by choice. Here the philosopher finds surprising similarities between some Analytic philosophers of the English-speaking world and the more speculative continental philosophers.The analysis of mental phenomenaWhen the specific phenomena that go to make up the mental are considered, one finds that they all raise philosophical issues, only some of which can be sketched here. Mental phenomena are traditionally divided into three areas: the cognitive, which is concerned with knowledge; the affective, with feeling; and the volitional, with action. It is no longer believed that this division reflects the three so-called basic faculties that comprise the mind; nevertheless, as a very rough classification, it provides a convenient approach to the variety of mental phenomena.The cognitive (cognition)Many philosophers since Plato have taken man's ability to know as the characteristic distinguishing him from all other animals. The very name of his species, Homo sapiens, means “man the knower.”If one asks what knowledge is, he has raised the central problem of a major field of philosophy, epistemology (see epistemology). But there is also a very important psychological aspect to knowledge, and that is where the philosophy of mind becomes relevant. It is often claimed, for example, that knowing that something is so entails believing that it is so; and the nature of belief lies clearly within the province of the philosophy of mind. Since a person does not lose a belief when he is not consciously attending to it, the approach to belief most in favour today is to treat it as a disposition, which, like all such, comes to open expression only sporadically. Other psychological phenomena falling within the area of the cognitive are attention, sense perception, understanding, memory, inference, and doubt. The view that each of these requires a subjective experience has been effectively refuted in the writings of Ludwig Wittgenstein (Wittgenstein, Ludwig), one of the seminal thinkers of modern Linguistic Analysis. Remembering that the oven is still turned on may consist in nothing but getting up in the middle of a conversation, going over to the oven, and turning it off, all the while animatedly continuing the conversation. But exactly why this is called “remembering that the oven is still on” is not clear. Perhaps the best that can be said is that there are analogies between such instances of remembering and other, more self-conscious instances. It is the task of the philosophy of mind to examine, classify, and analyze the relations among such phenomena.The affectiveMan has not only the capacity to know but also the capacity to respond emotionally to what he knows. A man may not only believe that some event will occur, but he may also dread it or welcome it. Concerning the things that a person knows, he may approve or disapprove, love or hate, pity or envy, enjoy or abhor. Here, although the subjective experience often plays an important role, it clearly is not the whole story. To enjoy doing something, as has been pointed out, is not to do the thing and also undergo a series of experiences of enjoyment; it may simply be to do the thing when circumstances permit and make efforts to avoid its cessation or interruption. But a disposition-to-behave approach will be less successful for other affective phenomena. For example, people have feelings about the past—regret, nostalgia, pride—feelings in which future behaviour plays a relatively minor role.All of the affective phenomena so far considered have the property of intentionality, of being directed toward an object. It is clear, however, that this is not a sufficient condition for defining the affective, since it marks out too broad a scope—including, for example, believing, which, though intentional, falls not within the affective but within the cognitive. But neither does intentionality seem to be a necessary condition of the affective. Moods such as depression, anxiety, or joviality may not have any specific object, though it is sometimes replied that such emotions take as objects anything the person happens to think of. Sensations also do not seem to be intentional, even though they are usually classified as affects. One view is that sensations are really cognitions—the awareness of some bodily disturbance. The difficulty in trying to decide whether a sensation is an affect or a cognition further illustrates the inadequacy of the classification of mental phenomena into the cognitive, affective, and volitional.The volitionalIntellect and emotion often come to expression in volition and action, important topics in the philosophy of mind—topics that comprise such concepts as motive, desire and purpose, deliberation, decision, intention, attempt, and action, both voluntary and involuntary.There is a rough distinction to be made between the things that happen to a person and the things he does or makes to happen. If a person slips on the ice, it is something that happens to him; if he walks on the ice, it is something that he does. “Henry slid on the ice” is ambiguous: it may report something that happened to Henry or something that Henry did, depending upon the meaning. In this example, the observable event may be the same: from a photograph of Henry sliding on the ice one may not be able to tell which it is. The problem of action is primarily to understand this distinction and its ramifications. Wittgenstein once put the question this way: “And the problem arises: what is left over if I subtract the fact that my arm goes up from the fact that I raise my arm?”There are a number of different answers: (1) Actions are events produced by causes of certain sorts—volitions or acts of will according to some theories; beliefs and desires under other theories; and simply persons or agents in yet another theory. (2) Actions are events that are “caused” in a special sense; they have a teleological rather than an efficient or mechanical cause, or an immanent (or originating) cause rather than one that is merely a reaction to, or modification of, an action coming from some other source. (3) Actions are events that are properly characterized and assessed in terms of rules of conduct, or principles of rational and ethical behaviour, and for which the agent is held responsible, liable, accountable, to be praised or blamed, rewarded or punished.Any theory of action is expected to throw light on the issue of free will, a matter of great importance for ethical theory. If the philosopher holds that free will is compatible with determinism, any of the views above will allow for free will. Even if he holds that an action is not free if it has causes that eventually lie outside the agent, his view will be compatible with the various views of action unless he holds the version of (1)—that an action is an event produced by volitions or beliefs and desires—and also holds the additional thesis (2)—that volitions or beliefs and desires themselves have causes that lie outside the agent. Only then will there be no freedom of the will.Some metaphysical and epistemological issuesPersonal identity through timeA person, as he goes through life, changes in many ways; but he remains the person that he was. He is that person who was born on a certain day, that person who graduated 23rd in a particular high school class, who married on a certain date in a certain place; he has a particular identity through time. It is difficult to state what exactly it is that makes a person one and the same self through time.An obvious starting point is the fact that throughout a person's natural life he has the same body (human body) and that this is what makes him one and the same person throughout a particular period of time. But there are difficulties in this view. First, since the body cells are constantly being replaced and in some instances whole organs are transplanted, it is not clear what makes a particular body identical with a body that existed, say, 20 years earlier. A second difficulty arises through the hypothetical possibility of brain transplants; if two brains were interchanged, in all likelihood there would be a systematic interchange of memory, beliefs, personality and character traits, skills, and habits of thought and action. Such a transplant would incline one to say that not merely a small portion of each body had been interchanged but two people as well; for one also takes as a criterion of personal identity similarities through time of memory, personality, skills, and habits. After all, a man is often willing to say that this is the same person who did something in the past, not on the basis of knowing that it is the same body but on a quite different basis—that the person recounts the past situation with great accuracy, exhibits similar personal reactions, and displays the same skills.Because two different kinds of criteria, bodily and psychological, are used for determining personal identity, it is possible to imagine instances of conflict in which the criterion of bodily identity would indicate that it is a different person but the psychological criteria would indicate that it is the same person and vice versa. The Austro-Czech novelist Franz Kafka, known for his nightmarish works, in his short story Die Verwandlung (1915; The Metamorphosis) tells of a person who awoke one morning to find, to his horror, that he had the body of a large insect. Although his family accepted his conclusion that he was the same person even though he had an entirely different body, others would have disagreed. There is still, in fact, considerable disagreement among scholars on this whole issue—on how to state precisely the bodily criterion; on whether there is a psychological criterion as well and, if so, how it is to be formulated; on what is the basic criterion of personal identity; and on what to say about instances in which criteria conflict.Personal immortalityMany people believe that when the human body ceases to be a living system, there is not total annihilation of the person but that in some respect the person continues to exist. The philosopher of mind can put aside the various watered-down versions of immortality in which the person continues to exist in the remote sense that people still remember him or his works or that his influence continues through history. The philosopher does look with interest, however, on the claim that there is an immortality in which a person, in his survival, meets the psychological criteria of personal identity, of inheritance of memory, beliefs, habits, and personality characteristics.It is clear that a person's view of immortality will be affected by opinions that he holds about the relation of mind to matter. Given the versions of Materialism that urge the elimination of mental terms or their definition in bodily terms or that take bodily identity to be the basic criterion of personal identity, the very notion of survival after death is completely unintelligible. Many philosophers, however, reason that, since the notion of survival is intelligible, such versions of Materialism cannot be accepted. Central-state or identity theorists would admit survival to be an intelligible notion but would view it, like lightning without electricity, as something that never happens; they would thus be in agreement with many dualists, in particular epiphenomenalists and psychophysical parallelists. Even an interactionist would be free to accept or reject survival, as would a neutral monist.If a philosopher holds that survival is an intelligible notion, he is still left with the further question of whether it ever happens. In the past there have been various a priori arguments for survival after death. Arguments based upon the nature of the self, such as its indivisibility, can be found in Plato's Phaedo. Kant argued that man's moral principles require survival as a postulate. But among those today who hold that survival is intelligible, it is widely agreed that a priori arguments will not do. If there is survival, they say, it is a contingent fact and not a necessity; one must thus look to empirical data for guidance. A survey of the evidence shows that the case against survival, though strong, is by no means conclusive. One thing is clear: if there is survival, the survivors can theoretically give firsthand testimony to it, whereas if there is no survival, there will be no one to give such testimony.Knowledge of other minds (other minds, problem of)An important problem in the theory of knowledge has been the status of the belief in other minds, the belief that one's own consciousness is not the only consciousness in existence. Though few, if any, sane persons have seriously accepted solipsism (the view that one's own is the only consciousness), the grounds for rejecting it are not at all clear.Again, as with the problems of personal identity and personal survival, one's view of the relation of mind to matter is relevant. On various Materialistic views, the problem reduces itself to that of justifying the belief in an external world that contains other bodies of the appropriate sort and with the appropriate behaviour. But for dualists and immaterialists, who hold that mental phenomena are something irreducibly different from the physical, there is the further question of whether that something is unique to oneself or whether there are other instances of it in the world.Some scholars claim that individuals sometimes have direct awareness of the conscious states of others, either in telepathic experiences, moments of empathy, or even in everyday social intercourse. There is, moreover, a transcendental argument, found in Kant and defended by Strawson, holding that, unless a person could be confident of the existence of other minds, he could not be confident of the existence of his own mind. A different line of reasoning, the so-called argument from analogy, is based upon the similarities between one's own body and its behaviour, on the one hand, and other human bodies and their behaviour on the other. To pursue the argument, since a mind is known to be associated with one's own body, it is reasonable to conclude that another mind is associated with the body of another person. Finally, there is the view that the best way to explain the complex behaviour of other bodies, especially their ability to behave rationally and in particular to speak and communicate information, is to postulate other minds at work.None of these arguments compels strong conviction, certainly not the degree of conviction that all persons feel concerning the existence of other minds. Whether stronger arguments will be found, whether philosophers must admit that there is a considerable amount of faith required here, or whether they will reformulate their concepts of the mind in a more Materialistic way to bring them in closer accord with observable data remains to be seen.Remarkable progress in the development of high-speed electronic computers has led many philosophers to conclude that a suitably programmed computer with a sufficient memory capacity would have an actual mind capable of intelligent thought. The term artificial intelligence denotes the area of investigation that aims to develop computers with such capabilities.Two questions are intensely debated in this field. First, what are the theoretical limits to what can be achieved in the way of artificial intelligence? Despite phenomenal progress in recent years, no computer yet devised even approximates in its capacity the multiplicitous powers of the human mind. However, it would be most unwise at present to make dogmatic predictions about future developments. Second, assuming that the optimistic hopes of artificial intelligence researchers are realized, would such devices literally have minds or would they be mere imitations of minds? It is already common linguistic practice to describe computers as having memories, making inferences, understanding one language or another, and the like, but are such descriptions literally true or simply metaphorical? One group holds that computers will never be more than tools employed by the human intelligence to aid its own thinking. Another group holds that human intelligence itself consists of the very computational processes that could be exemplified by advanced machines, so that it would be unreasonable to deny the attribution of intelligence to such machines. The issue may remain unresolved until researchers in artificial intelligence have had more time to determine the limits of computer capabilities.Additional ReadingVarious formulations of Materialism can be found in the writings of the pre-Socratic philosophers, especially Leucippus and Democritus. Plato, Phaedo, Timaeus, Phaedrus, and books iv and x of the Republic, demonstrate his dualism and his views on the nature of the soul. Aristotle, De Anima (On the Soul), is a whole treatise devoted to the subject, expressing a qualified Materialism. Thomas Hobbes, Leviathan (1651), is radically Materialistic; whereas René Descartes, Meditationes de prima philosophia, 2nd ed. (1642), and other writings, presents a classic interactionist dualism. Dualism of the parallelist variety can be found in the writings of Gottfried Leibniz. Benedict De Spinoza, Ethica (1677), rejects both Materialism and dualism, expounding a double-aspect theory. George Berkeley, Treatise Concerning the Principles of Human Knowledge (1710), provides the classic statement and defense of Idealism (in his word, immaterialism). All the works above can be found in modern editions.The contemporary interest in the philosophy of mind is largely a result of the provocative work by Gilbert Ryle, Concept of Mind (1949, reprinted 1984). Also of great importance was the wholly new approach to all of philosophy taken by Ludwig Wittgenstein, Philosophical Investigations, 3rd ed. (1958, reissued 1973). There followed a spate of journal articles, some of the best of which are in the following anthologies: Myles Brand (ed.), The Nature of Human Action (1970); Antony Flew (ed.), Body, Mind, and Death (1964); Donald F. Gustafson (ed.), Essays in Philosophical Psychology (1964); Harold Morick (ed.), Introduction to the Philosophy of Mind (1970, reissued 1981); George Pitcher (ed.), Wittgenstein: The Philosophical Investigations (1966); Alan R. White (ed.), The Philosophy of Action (1968, reprinted 1977); and Oscar P. Wood and George Pitcher (eds.), Ryle (1970). Another useful work is David M. Rosenthal (ed.), The Nature of Mind (1991). Selections written from Existentialist and Phenomenological perspectives are found in Stuart F. Spicker (ed.), The Philosophy of the Body (1970). M. Merleau-Ponty, Phenomenology of Perception (1989; originally published in French, 1945), is also of interest. Introductory writings that include original contributions as well as balanced assessments are Gerald E. Myers, Self (1969); Alan R. White, The Philosophy of Mind (1967, reprinted 1978); Jerome A. Shaffer, Philosophy of Mind (1968); Colin McGinn, The Character of Mind (1982); Peter Smith and O.R. Jones, The Philosophy of Mind: An Introduction (1986); Rom Harré, Physical Being: A Theory for a Corporeal Psychology (1991), on how we think about the body in everyday life; and Dale Jacquette, Philosophy of Mind (1994).Analyses of particular mental phenomena are found in G.E.M. Anscombe, Intention, 2nd ed. (1963, reissued 1976); Harvey Richard Schiffman, Sensation and Perception, 3rd ed. (1990), a good textbook; Peter Geach, Mental Acts (1956, reissued 1971); Stuart Hampshire, Thought and Action, new ed. (1982); Anthony Kenny, Action, Emotion, and Will (1963, reissued 1976); Alasdair C. MacIntyre, The Unconscious (1958, reissued 1976); Norman Malcolm, Dreaming (1959, reissued 1976); R.S. Peters, The Concept of Motivation, 2nd ed. (1969); Richard Taylor, Action and Purpose (1966, reprinted 1973); and Alan R. White, Attention (1964).Works dealing with the problem of personal identity include Harold W. Noonan, Personal Identity (1989, reissued 1993), a rigorous introduction; Peter Unger, Identity, Consciousness, and Value (1990), for specialists; A.J. Ayer, The Concept of a Person (1963); and Chris L. Kleinke, Self-Perception: The Psychology of Personal Awareness (1978). The problem of one's knowledge of other minds is explored in Harold Morick (ed.), Wittgenstein and the Problem of Other Minds (1967, reissued 1981); Alvin Plantinga, God and Other Minds (1967, reissued 1990); and John Wisdom, Other Minds, 2nd ed. (1965). A defense of dualism may be found in John Foster, The Immaterial Self (1991); and W.D. Hart, The Engines of the Soul (1988). R.J. Nelson, The Logic of Mind, 2nd ed. (1989), offers a mechanistic approach to philosophy of mind; whereas John Eccles and Daniel N. Robinson, The Wonder of Being Human: Our Brain and Our Mind (1984), poses strong opposition to the “human-as-machine” approach. The implications of artificial intelligence are examined in Alan Ross Anderson (ed.), Minds and Machines (1964); Hubert L. Dreyfus, What Computers Can't Do, rev. ed. (1979); Daniel C. Dennett, Brainstorms (1978; reissued 1981), and Consciousness Explained (1991); and Paul M. Churchland, The Engine of Reason, the Seat of the Soul (1995).Jerome A. Shaffer Ed.
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