METAPHYSICS

the philosophical study whose object is to determine the real nature of thingsto determine the meaning, structure, and principles of whatever is insofar as it is. Although this study is popularly conceived as referring to anything excessively subtle and highly theoretical and although it has been subjected to many criticisms, it is presented by metaphysicians as the most fundamental and most comprehensive of inquiries, inasmuch as it is concerned with reality as a whole. branch of philosophy concerned with critically examining basic philosophical assumptions and identifying what exists insofar as it exists. Metaphysics interacts with such other philosophical studies as logic, epistemology, aesthetics, and ethics. Metaphysics has by tradition concerned itself with issues of broad philosophical interest. One of the most basic issues, first addressed by ancient Greek philosophers, is the existence and nature of forms, i.e., abstract realities which are objects of the mind. Since the classical Greek philosophers distinguished between objects of the real worldsensible thingsand objects of the mindideasmetaphysical philosophers have concerned themselves with the relationship between abstractions and substances, trying to determine whether both are real or whether one is somehow more real than the other. Metaphysicians have interpreted the natural world, the significance of time and space, and the existence and nature of God, all in an attempt to understand the relationship between form and idea. Metaphysical argument is by and large an a priori process. A priori arguments start with basic, mutually consistent assumptions and develop them through to their logical conclusions. If absurdities arise during this deductive process, the original principles must be rejected or reevaluated. Since metaphysical conclusions are by nature extremely general, all-encompassing assertions that are paradigms of thought rather than statements of empirical fact, refuting them with counterexamples is ineffective criticism. Moreover, unlike in the empirical sciences, where new knowledge supersedes old beliefs, numerous conflicting metaphysical theories have all stood the test of time, affirming the notion that there is no single metaphysical truth. The first metaphysicians, Parmenides and Plato, recognized a basic distinction between appearance and reality. Plato rejected the changeable, deceptive reality of the sensible world in favour of the unchanging and therefore truthful world of ideas. Aristotle began with Plato's distinction between form and matter and then integrated the two using a biological model. Aristotle assumed that matter was always moving toward its potential ideal form. In this way the material world is seen as a continuum of organic change. With the development of Christianity, philosophers became concerned with finding an a priori proof of God's existence. Thomism, based on the metaphysics of St. Thomas Aquinas, combined Aristotelian and Christian thought. According to St. Thomas, the contemplation of the everyday (which was the basis of Aristotle's examination of the relationship between form and matter) inevitably leads to the understanding that God exists and is the prime and sustaining cause of the material world. By examining the finite, ever-changing material world, one is inevitably led to the source of change, i.e., God. Ren Descartes caused another major shift in metaphysical thought. His dualistic philosophy defined the material and mental spheres as separate, independent realms. Rejecting the notion of God proposed by the Christian philosophers, Descartes postulated that the material world was set up by a prime agent, but thereafter, like a great mechanism, it ran free of divine interaction. Immanuel Kant accepted dualism but rejected Descartes's explanation and revolutionized metaphysics by demonstrating the importance of perception. According to Kant, objective reality must be perceived through the human constructs of time and space. Thus the human view of the material world would always be influenced by the perceiving mechanism. What earlier metaphysicians had considered objective reality, Kant rejected as such, subordinating all observation to the mechanism of observation. Materialism and Idealism tried to synthesize the concepts of mind and matter within a single theory. The Idealists merged the two spheres by subordinating matter to mind. Materialists assumed the antithetical position, subordinating mind to matter and asserting that all that existed was matter and that the mind was dependent on objective circumstances. Several philosophers have questioned the validity of metaphysical methodology and conclusions. David Hume asserted that all knowledge comes through the senses. Since all basic concepts are derived from sense experience, Hume concluded that there is no pure thought. Logical Positivism, a 20th-century school of philosophy, asserted that any statement's meaning depends on how it can be verified. Since metaphysical statements cannot be verified, Logical Positivists concluded that metaphysical assertions have no meaning. Ludwig Wittgenstein's criticism viewed metaphysical experience as something beyond the realm of language. Wittgenstein argued that there were things that could be said and things that could only be shown. Metaphysical theorizing is unsuccessful because it tries to talk about a realm that exists outside of the realm that language can illuminate. Additional reading These works deal mainly with the nature and possibility of metaphysics.For a discussion of the apparently conflicting views of Plato and Aristotle, see the commentary in Aristotle, Metaphysics, ed. by W.d. Ross, rev. ed., 2 vol. (1924, reissued 1966); and Werner Jaeger, Aristotle: Fundamentals of the History of His Development, 2nd ed. (1948, reprinted 1968; originally published in German, 1923). Modern discussions of the methods of metaphysics are found in Ren Descartes, The Philosophical Works of Descartes, trans. by Elizabeth S. Haldane and G.R.T. Ross, 2 vol. (191112, reprinted with corrections, 1981), and Philosophical Letters, trans. from the French and ed. by Anthony Kenny (1970). On the geometrical form of metaphysics, see the essay by Benedict Spinoza, Ethica, more geometrico demonstratis, available in a translation by W. Hale White and rev. by Amelia H. Stirling, Ethic: Demonstrated in Geometrical Order . . . , 4th ed. rev. (1927, reprinted 1930). Christian Wolff combined both the practice and theory of metaphysics in his voluminous metaphysical writings: Vernnfftige Gedanken von Gott, der Welt und der Seele der Menschen, new enlarged ed. (1751, reprinted 1983), Philosophia Prima Sive Ontologia, 2nd ed. (1736, reprinted 1962), Cosmologia Generalis, rev. ed. (1737, reprinted 1964), Psychologia Rationalis, rev. ed. (1740, reprinted 1972), and Theologia Naturalis, rev. ed., 2 vol. (173941, reprinted 2 vol. in 3, 197881). Alexander Gottlieb Baumgarten, Metaphysica, 7th ed. (1779, reprinted 1963), was in effect a digest of these last four works. The problem of the origin of ideas was first posed in John Locke, An Essay Concerning Humane Understanding (1690, reissued 1979), on which G.W. Leibniz wrote a critical commentary, Nouveaux essais sur l'entendement humain (1765), available also in an English translation ed. by Peter Remnant and Jonathan Bennett, New Essays on Human Understanding (1981). George Berkeley criticized Materialism in his Treatise Concerning the Principles of Human Knowledge (1710, reissued 1983), available also in a contemporary edition ed. by Colin M. Turbayne. David Hume applied Empiricist principles with complete generality in A Treatise of Human Nature, 3 vol. (173940, reprinted in 1 vol., 1975), and An Enquiry Concerning Human Understanding (1748, reissued 1977).Immanuel Kant first discussed metaphysical method in his essay Inquiry into the Distinctness of the Principles of Natural Theology and Morals, available in a translation by Lewis White Beck, Critique of Practical Reason and Other Writings in Moral Philosophy (1949); and Kant examined the whole question of the possibility of metaphysical knowledge in Critique of Pure Reason (1982; originally published in German, 4th ed., 1794), and Prolegomena to Any Future Metaphysics That Will Be Able to Come Forward as Science, trans. by Paul Carus (1902, rev. ed. 1977). For a sustained criticism of Kant's critical point of view, see the writings of G.W.F. Hegel, especially The Phenomenology of Mind, 2nd ed. (1931, reissued 1977; originally published in German, 1807), The Logic of Hegel, trans. from the German by William Wallace (1873, reprinted with the title Hegel's Logic, 1975), Hegel's Philosophy of Nature, 3 vol., ed. and trans. from the German by M.J. Petry (1970), and Hegel's Philosophy of Mind, trans. from the German by William Wallace, enlarged ed. (1971). These last three are translations from various editions of Hegel's Encycklopdie der philosophischen Wissenschaften, first published in 1817.Only a few 19th-century philosophers added to the fundamental criticisms of metaphysics developed by earlier writers. See, for example, Auguste Comte, Cours de philosophie positive, 6 vol. (183042), available also in an edition of selections, ed. by Stanislav Andreski, The Essential Comte (1974); and John Stuart Mill, System of Logic, 2 vol. (1843, reissued 1978). Mill was sharply criticized by Thomas Hill Green, Prolegomena to Ethics, 5th ed. (1907, reprinted 1969); and F.H. Bradley, The Principles of Logic, 2nd ed. rev. (1922, reissued 1963).For American metaphysical thought of the same period, see Charles Sanders Peirce, Collected Papers of Charles Sanders Peirce, ed. by Charles Hartshorne, Paul Weiss, and A.W. Burks, 8 vol. (193158, reissued in 4 vol., 197479); and William James, A Pluralistic Universe (1909, reprinted 1979).There are interesting remarks on the philosophy of philosophy in the works of Wilhelm Dilthey, especially vol. 5 of his Gesammelte Schriften, 5th ed., 12 vol. (1962). Twentieth-century criticisms of metaphysics derive mainly from the work of the Vienna Circle; see Viktor Kraft, The Vienna Circle: The Origin of Neo-Positivism (1953, reissued 1969; originally published in German, 1950). Ludwig Wittgenstein, Tractatus Logico-Philosophicus (1922, reissued 1983), was read as an improved version of Empiricism. Among the authors who influenced the Logical Positivists were Ernst Mach, The Science of Mechanics: A Critical and Historical Accident of Its Development, 6th ed. (1974; originally published in German, 9th ed., 1933); Alfred North Whitehead and Bertrand Russell, Principia Mathematica, 2nd ed., 3 vol. (192527, reprinted 196873); and Bertrand Russell, Our Knowledge of the External World as a Field for Scientific Method in Philosophy, rev. ed. (1926, reprinted 1972). A.J. Ayer (ed.), Logical Positivism (1959, reprinted 1978), anthologizes in translation some of the most famous papers from the Vienna Circle's periodical Erkenntnis. Ayer's own book, Language, Truth and Logic, 2nd ed. rev. (1946, reprinted 1970), was extremely successful in spreading Positivist ideas in America and Britain, where the work of George Edward Moore, especially Defence of Common Sense, in his Philosophical Papers, pp. 3259 (1959, reprinted 1977), had created an atmosphere in which metaphysical claims were viewed with suspicion. Another influential book along the same lines as Ayer's was Hans Reichenbach, The Rise of Scientific Philosophy (1951, reprinted 1968); see also Morris Lazerowitz, The Structure of Metaphysics (1955, reprinted 1968), which attempts to explain the activities of metaphysicians in terms of psychoanalysis. For criticism of Positivist ideas, see Winston H.F. Barnes, The Philosophical Predicament (1950); D.F. Pears (ed.), The Nature of Metaphysics (1957, reprinted 1970); and Karl R. Popper, Conjectures and Refutations: The Growth of Scientific Knowledge, 4th ed. rev. (1974). R.G. Collingwood, An Essay on Metaphysics (1940, reprinted 1979), purports to answer Ayer but instead contains an unconventional view of metaphysics as historical analysis. A division of metaphysical systems into descriptive and revisionary is proposed in P.F. Strawson, Individuals: An Essay in Descriptive Metaphysics (1959, reprinted 1964). For further discussions, see W.H. Walsh, Metaphysics (1963, reprinted 1966); A.J. Ayer, Metaphysics and Common Sense (1969, reprinted 1973); Anthony Quinton, The Nature of Things (1973, reprinted 1978); Stephan Krner, Metaphysics, Its Structure and Function (1984); and D.W. Hamlyn, Metaphysics (1984). For a very different approach, compare Martin Heidegger, An Introduction to Metaphysics (1959, reissued 1961; originally published in German, 1953).Recent European thought is summarized in Rdiger Bubner, Modern German Philosophy (1981), trans. by Eric Matthew from an unpublished manuscript, which provides a critical survey of recent philosophy in Germany and compares it to philosophical work in the English-speaking world; Vincent Descombes, Modern French Philosophy (1980; originally published in French, 1979), a survey of contemporary philosophy in France; and Alan Montefiori (ed.), Philosophy in France Today (1983), a collection of essays by French philosophers describing their own work and interests. Andr De Muralt, The Idea of Phenomenology: Husserlian Exemplarism (1974; originally published in French, 1958), studies the main themes in phenomenological philosophy. A useful introductory guide with an extensive bibliography is David Steward and Algis Mickunas, Exploring Phenomenology: A Guide to the Field and Its Literature (1974). Herbert Spiegelberg, The Phenomenological Movement: A Historical Introduction, 3rd rev. ed. (1982), discusses central themes in Phenomenology; and in The Context of the Phenomenological Movement (1981), he explains the background to that movement.Karl-Otto Apel, Towards a Transformation of Philosophy (1980; originally published in German, 1972), is an influential study of objectivity, subjectivity, and interpretation. Jrgen Habermas, Knowledge and Human Interests, 2nd ed. (1978; originally published in German, 1968), is a critique of Positivism. Hans-Georg Gadamer, Truth and Method (1975, reissued 1982; originally published in German, 2nd ed., 1965), gives a Heideggerian account of the interpretation of experience. Another influential contribution to recent philosophy is Emmanuel Lvinas, Totality and Infinity: An Essay on Exteriority (1969, reissued 1979; originally published in French, 1961).Works that analyze the thought of specific philosophers include: R.E. Aquila, Two Problems of Being and Nonbeing in Sartre's Being and Nothingness, Philosophy and Phenomenological Research, 28(2):167186 (December 1977); Suzanne Bachelard, A Study of Husserl's Formal and Transcendental Logic (1968; originally published in French, 1957); John D. Caputo, The Mystical Elements in Heidegger's Thought (1978); Jacques Derrida, Edmund Husserl's Origin of Geometry: An Introduction (1978; originally published in French, 2nd rev. ed., 1974); Joseph P. Fell, Heidegger and Sartre (1979); Wolfgang Walter Fuchs, Phenomenology and the Metaphysics of Presence: An Essay in the Philosophy of Edmund Husserl (1976); Agnes Heller (ed.), Lukcs Reappraised (1983; U.K. title, Lukcs Revalued); Sang-Ki Kim, The Problem of the Contingency of the World in Husserl's Phenomenology (1977); A.M. Mirvish, Merleau-Ponty and the Nature of Philosophy, Philosophy and Phenomenological Research, 43(4):449476 (June 1983); Marie-Luise Schubert Kalsi, Alexius Meinong on Objects of Higher Order and Husserl's Phenomenology (1978); and Anthony Thiselton, The Two Horizons: New Testament Hermeneutics and Philosophical Description with Special Reference to Heidegger, Bultmann, Gadamer, and Wittgenstein (1980). William Henry Walsh A.C. Grayling Argument, assertion, and method in metaphysics Attention is now turned from description of the content of particular metaphysical views to more general treatment of the nature of metaphysical claims. The questions that will arise in this section concern such things as the nature and basis of metaphysical assertions, the character of metaphysical arguments and of what are taken to be metaphysical proofs, and the parts played in metaphysical thinking by insight and argument, respectively. They come together in the inquiry as to whether metaphysics can be said to be a science and, if so, what sort of a science it is. Metaphysics as a science Nature of an a priori science Sciences are broadly of two kinds, a priori and empirical. In an a priori science such as geometry, a start is made from propositions that are generally taken to be true, and the procedure is to demonstrate with rigorous logic what follows if they are indeed true. It is not necessary that the primary premises of an a priori science should in fact be truths; for the purposes of the system they need only be taken as true, or postulated as such. The main interest is not so much in the premises as in their consequences, which the investigator has to set out in due order. The primary premises must, of course, be consistent one with another, and they may be chosen, as in fact happened with Euclidean geometry, because they are thought to have evident application in the real world. This second condition, however, need not be fulfilled; a science of this kind can be and commonly is entirely hypothetical. Its force consists in the demonstration that commitment to the premises necessitates commitment to the conclusions: the first cannot be true if the second are false. This point about the hypothetical character of a priori sciences has not always been appreciated. In many classical discussions of the subject, the assumption was made that a system of this kind will start from as well as terminate in truths and that necessity will attach to premises and conclusions alike. Aristotle and Descartes both spoke as if this must be the case. It is clear, however, that in this they were mistaken. The form of a typical argument in this field is as follows: (1) p is taken as true or given as true; (2) it is seen that if p, then q; (3) q is deduced as true, given the truth of p. There is no need here for p to be a necessary or self-guaranteeing truth; p can be any proposition whatsoever, provided its truth is granted. The only necessity that needs to be present is that which characterizes the argument form, If p is true, and p implies q, then q is true, that is [p (p q)] q, in which symbolizes and, and means implies; and this is a formula that belongs to logic. It is this fact that makes philosophers say, misleadingly, that a priori sciences are one and all analytic. They are not because their premises need not answer this description. They, nevertheless, draw their lifeblood from analytic principles. Criticisms of metaphysics Metaphysics has many detractors. The man who aspires to know reality as against mere appearance, to use Bradley's description, is commonly taken to be a dreamer, a dupe, or a charlatan. Reality in this context is, by the metaphysician's own admission, something that is inaccessible to sense; as Plato explained, it can be discovered only by the pure intelligence, and only if the latter can shake itself free of bodily encumbrances. The inference that the metaphysical world is secret and mysterious is natural enough. Metaphysics in this view unlocks the mysteries and lets the ordinary man into the secrets. It is, not to put too fine a point on it, a study of the occult. Metaphysics as knowledge of the supersensible That there are aspects of metaphysics that lend colour to this caricature can scarcely be denied. The language of Plato, in particular, suggests an absolute distinction between the deceitful world of appearances, which can never be an object of knowledge, and the unseen world of Forms, each of which is precisely what it appears to be. Plato urged his readers not to take seriously the things of sense; he told them that everything having to do with the senses, including the natural appetites and the life of the body, is unreal and unimportant. The philosopher, in his view, needs to live an ascetic life, the chief object of which is to cultivate his soul. Only if he does this, and follows a rigorous intellectual training, has he any hope of getting the eye of his soul fixed on true reality and so of understanding why things are what they are. Yet even this program admits of an innocuous, or relatively innocuous, interpretation. The dialectician, as Plato called his metaphysical philosopher, is said in one place to be concerned to give an account, and the only things of which he can give an account are phenomena. Plato's interest, despite first appearances, was not in the unseen for its own sake; he proposed to go behind things visible in order to explain them. He was not so much disdainful of facts as critical of accepted opinions; his attack on the acquiescence in appearances was an attack on conventional wisdom. That this was so comes out nowhere more clearly than in the fact that his targets included not just beliefs about what there is but also beliefs about what is good. It is the opinions of the many that need correction and that can happen only if men penetrate behind appearances and lay hold on reality. Plato is often presented as an enemy of science on the ground that he was bitterly opposed to Empiricism and because he said that, if there was ever to be progress in astronomy, the actual appearances of the starry heavens must be disregarded. He understood by Empiricism, however, the uncritical acceptance of apparent facts, with the attempt to trace regularities in them; it is an attitude that, in his view, is marked by the absence of thought. As for the starry heavens, it is certainly difficult to take Plato quite literally when he compares their function in astronomy to that of a well-drawn diagram in geometry. Yet he was not wrong to suggest that no progress could be made in astronomical inquiries until appearances were seen to be what they were and not taken for absolute realities. The subsequent progress of astronomy has shown this view to be entirely correct. There are respects in which Plato's attitude to phenomena was precisely the same as that of the modern scientist. The fact remains, nevertheless, that he believed in a realm of unseen realities, and he is of course far from being the only metaphysician to do so. Many, if not quite all, metaphysicians are committed to claiming knowledge of the supersensible, in some degree at least; even Materialists are alleged to make this claim when they say that behind the familiar world of everyday experience there lies material substance that is not accessible to the senses. It has been a commonplace among critics of metaphysics since the early 18th century that no such claims can be justified; the supersensible cannot be known about, or even known of, whether directly or by inference. Problems in metaphysics To give a comprehensive account of the main problems of metaphysics in the space of a few pages is clearly quite impossible. What follows is necessarily highly selective and to that extent misleading; it, nevertheless, attempts to offer an introduction to metaphysical thinking itself rather than reflection on the nature of metaphysics. The existence of forms, categories, and particulars Forms The early Greek philosophers asked the question ti to on, What is existent? or What is really there? They originally interpreted this as a question about the stuff out of which things were ultimately made, but a new twist was given to the inquiry when Pythagoras, in the late 6th century BC, arrived at the answer that what was really there was number. Pythagoras conceived what is there in terms not of matter but of intelligible structure; it was the latter that gave each type of thing its distinctive character and made it what it was. The idea that structure could be understood in numerical terms was probably suggested to Pythagoras by his discovery that there are exact correlations between the lengths of the strings of a lyre and the notes they produce. By a bold extrapolation he seems to have surmised that what held in this case must hold in all cases. The Pythagorean theory that what is really there is number is the direct ancestor of the Platonic theory that what is really there is Forms, or Ideas (eide, or ideai). Plato's Forms were also intelligible structures and not material elements, but they differed from Pythagorean numbers by being conceived of as separately existent. There was, as Plato put it, a place accessible to the intelligence, which was the place, or realm, of Forms. Each Form was a genuine existent, in the sense of being precisely what it pretended to be; the Form of Beauty, for example, was beautiful through and through. By contrast, the many particular things that partook of or resembled what was truly beautiful were one and all defective. However beautiful any one of them might be, it was also in another respect lacking in beauty. It turned out to possess contradictory characteristics, and as such could never be identified with true reality. Plato had taken over from his predecessor Heracleitus, who flourished at about the beginning of the 5th century BC, the doctrine that the world of sensible things is a world of things in constant flux; as he put it in the Theaetetus, nothing is in this world because everything is in a state of becoming something else. Forms were needed to provide stable objects for knowledge as well as to answer the question of what is ultimately real. Although Plato played down the reality of sensible things, making them mere objects of opinion and describing them as falling between what is and what is not, he did not deny their existence. It was not his thesis that Forms alone exist. On the contrary, he appears to have held that God (who was certainly not a Form) had somehow fashioned the physical world on the model of the Forms, using space as his material. This is the description that is given in the Timaeus, in a passage that Plato perhaps meant his readers not to take quite literally but that stated his view as plainly as he thought it could be stated. In this passage God appears in the guise of the Demiurge, although he is referred to freely in other Platonic dialogues. Souls were also distinct from Forms in Plato's thought. In the discussions that developed around the theory of Forms, many difficulties were revealed, most of them familiar to Plato himself. The question of how the one Form was supposed to relate to the many particulars that participated in or resembled it was nowhere satisfactorily answered. The difficulty turned on how the Form was to be thought of at once as an existent and as a structure. Plato seemed on occasion to think of it as a structure hypostatized, or given real existence. This thesis led to the antinomies exposed in the third man argument. According to this theory, particular men were alleged to be human because of their relationship to Man himself; i.e., the Form of man. But whence did the latter derive its nature? Must there not be a second Form to explain what the first Form and its particulars have in common, and will not this generate an infinite regress? Again, the problem of the precise population of the world of Forms never got a definitive solution, perhaps because the theory of Forms was put to more than one purpose. Sometimes it was said that there is a Form corresponding to every general word, but elsewhere the theory was that what is merely negative (e.g., lifeless) has no need of a special Form, nor does what is manufactured. There is even a question as to whether trivial everyday things such as mud and hair and dirt have Forms, though it is agreed that there is a Form of man. The problems just referred to were stated trenchantly in Plato's dialogue the Parmenides; the discussion there ends with the statement that the Forms must be retained if an account of intelligible discourse is to be given, but no indication is offered as to how the theory is to be refurbished. Some Platonic scholars have inferred that Plato virtually gave it up, but such evidence as there is suggests that he only transformed it into a theory of Form-numbers, more openly Pythagorean than the earlier version. There are many references in Aristotle to this theory of Form-numbers, but no writing of Plato's own on the subject has survived, and it is virtually impossible at this late stage to say what this theory really comprised. One further feature of the theory of Forms must be mentioned here: the view that there is a supremely important Form, the Form of goodness, or of the Good, which somehow determines the contents of the world of Forms and brings order into it. In a celebrated but brief and tantalizing passage in Politeia, the Form of the Good is spoken of as being to the intelligible realm what the sun is to the visible realm; just as the sun makes living things grow and renders them visible, so the Good is responsible for the existence and intelligibility of Forms, though it is itself on the other side of Being. This passage had a tremendous historical influence on the Neoplatonists, who saw it as anticipating the ultimate ineffable realitythe One, from which everything describable was in some way an emanationin which they came to believe. It seems possible, however, that Plato had no such mystical thoughts in mind but simply wanted to say that the world of Forms is ordered through and through, everything in it being there for a purpose. The Form of Good is, in fact, the counterpart of the nous (Mind) of Anaxagoras, another of Plato's predecessors, which was supposed to arrange everything for the best. Tendencies in contemporary metaphysics Tendencies in the United States Kant's efforts to limit metaphysics opened new lines for its development. He had thought that reason is established by being limited and that some truths are certain independent of anything that can happen in experience because experience is structured by the interpretive categories reflected in these truths. Thus, it is possible to be certain of the world in its general structure but only insofar as it is an experienced, or phenomenal, worldthat is, a world known by man, not a world as it is in itself. Hegel, however, argued persistently that knowledge of a thing unknowable in itself is a contradiction and that reason can know all that is real if the mind first accepts the given thing as always already within experience as other. The mutual implication of knowing mind and reality known is accepted, and a science of self-consciousness that relates all categories and all reality to the knowing subject is envisaged. Thus, Kant's mutual implication of knowing subject and phenomenal thing was given ultimate metaphysical validity by Hegel, and Kant's reformulations of traditional dualismse.g., subjectobject, appearancereality, perceptualcategorial, immanenttranscendent, regulativeconstitutivebecame momentous for metaphysics. John Dewey In this milieu, John Dewey, an American educational reformer and pragmatic philosopher, published his Kant and Philosophic Method in 1884 in the journal of a group known as the St. Louis Hegelians. Although Dewey later rejected the full-scale Hegelianism expressed in the article, he did so only after gathering up in a partial synthesis the thought of both Kant and Hegel. In this he sounded the thematic notes of much contemporary American and continental metaphysics. Whether or not this metaphysics is explicitly termed transcendental (that is, concerned with experience as determined by the mind's conceptual and categorial makeup), it does two things: (1) it affirms Kant's insight that physical particulars cannot first be identified and later interrelated by means of the categories, but, to be identified at all, they must be assumed to be already categorized, and reasoning must proceed to expose those categorial structures that make the actuality of knowledge possible; (2) it agrees with Hegel's critique at least to the extent that Kant's idea that the source of sensations is external to the mind in a noumenon is regarded as a transgression of Kant's own doctrine that the categories, particularly that of causation, can be applied only within phenomenal experience. Dewey thought that Kant confused the empirical and transcendental standpoints by mixing analysis of the organism as sensationally responsive with analysis of mind. Kant forgot that it is only because the knowing subject already grasps the world through its categories that it can self-deceivingly regard its sensations as subjective and as caused by something not known. Thus, for Dewey, The relation between subject and object is not an external one; it is one in a higher unity that is itself constituted by this relation. In Dewey's extended later thought, metaphysics became the study of the generic traits of existence. Concern with God and immortality slips nearly from view, and this is typical of much contemporary philosophy. Even so, Dewey's rethinking of the subjectobject relation engenders a concept of a democratic and scientific community of persons, bound to each other through common ideals, which has religious overtones. Vague and ambivalent as this concept may be, it helps undermine the whole contrast between immanent and transcendent and leads metaphysics on new paths. Types of metaphysical theory To complement and, in a way, to correct this brief survey of the problems of metaphysics it will be useful at this point to insert a short summary of a number of overall metaphysical positions. Metaphysics, as already noted, professes to deal with the world as a whole; the thoughts of a metaphysician, if they are to make any impact at all, must be connected in a system. The object in what follows will be to present in outline metaphysical systems that have exercised and, indeed, continue to exercise a strong intellectual appeal. In all cases but one, these systems were given classical shape by particular philosophers of genius. Relatively little attention, however, will be paid to this fact here because the present concern is with types of view rather than with views actually held. Thus, reference will be made to Platonism instead of to the philosophy of Plato, and so on in other cases. Platonism The essence of Platonism lies in a distinction between two worlds, the familiar world of everyday life, which is the object of the senses, and an unseen world of true realities, which can be the object of the intellect. The ordinary man recognizes the existence of the former and ignores that of the latter; he fails to appreciate the extent to which his beliefs both about fact and about values are arbitrarily assumed and involve internal contradictions. The philosopher is in a position to show him how insubstantial is the foundation on which he takes his stand. The philosopher can demonstrate how little thought there is in popular conceptions of good and evil, and he can show that the very concept of sense knowledge involves difficulties because knowledge presupposes a stable object, and the objects of sense are constantly changing. The claim, however, is that he can do more than this. Because of the presence in him of something like a divine spark, he can, after suitable preparation, fix his intellectual gaze on the realities of the unseen world and, in the light of them, know both what is true and how to behave. He will not attain this result easilyto get to it will involve not only immense intellectual effort, including the repeated challenging of assumptions, but also turning his back on everything in life that is merely sensual or animal. Yet, despite this, the end is attainable in principle, and the man who arrives at it will exercise the most important part of himself in the best way that is open to him. That this type of view has an immediate appeal to persons of a certain kind goes without saying. There is ample evidence in poetry and elsewhere of the frequently experienced sense of the unreality of familiar things and the presence behind them of another order altogether. Platonism may be said to build on intuitions of this kind; as a metaphysics, its job is to give them intellectual expression, to transfer them from the level of sentiment to that of theory. It is important, however, to notice that Platonism is not just the intellectualizing of a mood; it is an attempt to solve specific problems in a specific way. In Plato's own case, the problems were set by loss of confidence in traditional morality and the emergence of the doctrine that man is the measure of all things. Plato thought he could counter this doctrine by appeal to another contemporary fact, the rise of science as shown in the development of mathematical knowledge. Mathematics, as he saw it, offered certain truth, although not about the familiar world; the triangle whose properties were investigated by the geometrician was not any particular triangle but the prototype that all particular triangles presuppose. The triangle and the circle belonged not to the world of the senses but to the world of the intelligence; they were Forms. If this could be said of the objects of mathematical discourse, the same should also be true of the objects of morality. True justice and true goodness were not to be found in popular opinions or human institutions but should be seen as unchanging Forms, eternally existing in a world apart. Modern philosophers have found much to criticize in this system: as indicated already, they have objected that Forms are not so much existents as abstractions, and they have found the argument from science to morality quite inconclusive because of what they allege to be an absolute dichotomy between fact and value. It may be that nobody today can subscribe to Platonism in precisely the form given it by Plato himself. The general idea, however, has certainly not lost its hold, nor have the moral perplexities to which Plato hoped to find an answer been dissipated by further thought.