The philosophy of Immanuel Kant (1724–1804) radically transformed the rationalism and empiricism of the seventeenth and eighteenth centuries and has set many of the problems for epistemology, metaphysics, and philosophy of science, moral and political philosophy, aesthetics, philosophy of history, and philosophy of religion ever since. Almost all philosophy after Kant could be divided into either "Kantianism" or "anti-Kantianism," but it is natural to reserve the term Kantianism to designate the philosophy of Kant himself, his immediate followers, and a variety of movements in the late nineteenth century and the twentieth century that have explicitly identified themselves with Kant.
Kant developed his philosophy after thirty years of reflection on foundational problems in contemporary natural science; on the rationalism of René Descartes (1596–1650), Gottfried Wilhelm Leibniz (1646–1716), and Christian Wolff (1679–1754); on the critique of rationalism by Christian August Crusius (c. 1715–1775) and David Hume (1711–1776); and on the political and educational views of Jean-Jacques Rousseau (1712–1778). Kant presented his mature views in the Critique of Pure Reason (1781, substantially revised in 1787), the Critique of Practical Reason (1788), and the Critique of the Power of Judgment (1790); in the Prolegomena to Any Future Metaphysics (1783) and Groundwork of the Metaphysics of Morals (1785); in two detailed works applying his general principles, the Metaphysical Foundations of Natural Science (1786) and the Metaphysics of Morals (1797), comprising a "Doctrine of Right" and a "Doctrine of Virtue"; and in polemical works such as Religion within the Boundaries of Mere Reason (1793), a bold argument that the central concepts of Christianity can have only symbolic value for pure reason, and The Conflict of the Faculties (1798), an argument for the freedom of philosophical thought.
In these works, Kant argued that both ordinary experience and natural science rest on informative but certain principles, or "synthetic a priori cognitions," such as that every event we can place at a determinate position in time must be linked to antecedent events by causal laws, which we can explain only by supposing that they reflect the forms of our own thought, in particular the spatial and temporal forms of our intuitions or perceptions and the logical categories of our understanding that we impose on our experience. But by the same token, these forms of intuition and thought can determine only how things appear to us, not how they are in themselves (Kant called this doctrine "transcendental idealism"). Kant then argued that when we conceive of the soul, the world as a complete whole, or God, we overstep the limits of our sensory perception and can have no genuine knowledge of such things.
However, the gap between appearance and things in themselves that explains the certainty of the application of the fundamental principles of our knowledge to the former also makes it at least possible for us to conceive of, if not know, the latter, particularly to conceive of ourselves as being free to make moral choices that may seem inconsistent with the determinism of our actions in the empirical world and of a God who is the author of laws of nature that are ultimately consistent with the laws of morality. Kant argued that the latter are given by our own pure practical rather than theoretical reason and that we can know them without any appeal to God; the laws of morality are discerned by pure reason as necessary to achieve autonomy, the independence of our actions from determination by the mere inclinations of ourselves or others.
Kant then argued that the fundamental principle of justice is that each person must be allowed the maximal freedom of action consistent with a like allowance for all others and that we have ethical duties to promote the free and effective use of our capacities to set and pursue our own ends and those of others, which cannot be coercively enforced within the political sphere. Finally, Kant argued that our pleasures in the beautiful and the sublime are experiences of the disinterested freedom of the imagination from constraint by the direct demands of science and morality, but also that as an experience of freedom of the imagination, aesthetic experience is indirectly conducive to moral and political development. He also argued that a teleological view of nature as a purposive system, while of merely heuristic value for the pursuit of natural science, is also a morally valuable perspective on the world and our place within it.
Kant's work immediately produced both acclaim and hostility. It was first popularized by the 1786 Letters on the Kantian Philosophy by Karl Leonhard Reinhold (1757–1823), but by 1789 Reinhold had turned against Kant's dualisms—his distinctions between sensibility and understanding, between appearances and things in themselves, and between theoretical cognition and practical reason—and initiated the attempts to derive all of philosophy from a single principle that would be taken up in the "absolute idealism" of Johann Gottlieb Fichte (1762–1814), Friedrich Wilhelm Joseph Schelling (1775–1854), and Georg Wilhelm Friedrich Hegel (1770–1831). Other thinkers remained closer to Kant, especially the poet and historian Friedrich Schiller (1759–1805), who, in "On Grace and Dignity" (1793) and the Letters on the Aesthetic Education of Mankind (1795), argued for a greater confluence between our inclinations and our moral principles than Kant thought possible without being tempted by the monism of the absolute idealists. Johann Wolfgang von Goethe (1749–1832) was also deeply affected by Kant's third critique in the development of his own conception of nature.
Hegel's dominance of German philosophy in the 1820s through the 1840s ended the first wave of Kantianism, but the version of Kantianism propounded by Arthur Schopenhauer (1788–1860) in the Fourfold Root of the Principle of Sufficient Reason (1813) and The World as Will and Representation (1818) became influential after 1848 and prepared the way for a tremendous resurgence in the influence of Kant in German philosophy beginning in the 1860s. The "neo-Kantian" movement begun at that time dominated German philosophy until the 1920s. This movement took many forms. The scientist Hermann Helmholtz (1821–1894) gave a psychological interpretation of Kant's conception that the mind brings its own innate structure to perception, which influenced research into perception well into the twentieth century. But within academic philosophy, the two main forms of neo-Kantianism were the Marburg and Heidelberg schools.
The main representatives of the Marburg school were Hermann Cohen (1842–1918), Paul Natorp (1854–1924), and Ernst Cassirer (1874–1945). Cohen made his reputation with a series of commentaries on Kant's three critiques, published between 1871 and 1889, and then with his own system of philosophy, published between 1902 and 1912. He also published The Religion of Reason out of the Sources of Judaism (1919), an influential work on Judaism modeled on Kant's Religion. Cassirer's main work was the three-volume Philosophy of Symbolic Forms (1923–1929; trans. 1953–1957 with a fourth volume posthumously published in 1996). The Marburg school developed Kant's idea that we bring to both ordinary experience and more formalized science presuppositions reflecting the structure of our own thought; but especially by the time of Cassirer the school also recognized that we bring a multiplicity of such principles to our experience and that they may change over time. Cassirer's views were to some extent paralleled by those developed by the British philosopher Robin George Collingwood (1889–1943) in his Essay on Philosophical Method (1933) and Essay on Metaphysics (1940), although Collingwood did not call himself a neo-Kantian.
The chief representatives of Heidelberg neo-Kantianism were Wilhelm Windelband (1848–1915) and Heinrich Rickert (1863–1936). They stressed Kant's distinction between the principles of theoretical and practical reason and focused attention on our projections of values as well as knowledge into our experiences. Rickert developed the philosophical views of the school in The Limits of Concept Formation in Natural Science (1896–1902; trans. 1986) and Science and History (1899; trans. 1962). Both Windelband and Rickert also stressed the difference between the methods of natural science and history and thereby greatly influenced the methodological thought of the sociologist Max Weber (1864–1920), especially his theory of "ideal types" and his distinction between fact and value in the practice of social science.
Kant in the Later Twentieth Century
Kantianism in the early twentieth century was not limited to the self-designated neo-Kantian schools, however. The 1928 Logical Structure of the World (trans. 1967) by Rudolf Carnap (1891–1970) was clearly a modernization of Kant's theory of our application of the forms of logic to the raw data of our experience, as was the nearly contemporaneous Mind and World Order (1929) by the American Clarence Irving Lewis (1883–1964), who was himself influenced by the many Kantian elements in the works of Charles Sanders Peirce (1839–1914). The main revival of interest in Kant in the Anglo-American world came after World War II, however. In Britain, a great revival of Kantian philosophy was stimulated by two books by Sir Peter Strawson (1919–), Individuals: An Essay on Descriptive Metaphysics (1959) and The Bounds of Sense: An Essay on Kant's Critique of Pure Reason (1966). Strawson based his appropriation of Kant on a theory of meaning, arguing that a subject can apply the concept of his own self only in contrast to a concept of an objective world, while Jonathan Bennett (1930–) stayed closer to Kant in his Kant's Analytic (also 1966), arguing that it is our judgments about our own experience that can be confirmed only within a structure of judgments about the external world.
The work of Strawson and Bennett initiated a major debate about "transcendental arguments" in the United States as well as Britain that continued into the twenty-first century. Meanwhile, in the United States interest in Kant was independently inspired by the work of Wilfrid Sellars (1912–1989), whose famous attack upon the "myth of the given" in his "Empiricism and the Philosophy of Mind" (1956) was clearly intended as an alternative to C. I. Lewis's version of Kant and whose Science and Metaphysics: Variations on Kantian Themes (1968) presented a Peircian version of Kant using the resources of contemporary philosophy of language.
The strongest influence of Kant on contemporary philosophy, however, was mediated by the political philosopher John Rawls (1921–2002), whose A Theory of Justice (1971) was Kantian in both method and substance. Rawls argued that principles of distributive justice should be chosen in an "original position" of impartiality that models Kant's conception of universality and that the principles that would be so chosen would prioritize equal liberty over other forms of equality, reflecting Kant's emphasis on autonomy as the fundamental moral and political value. Rawls's work has inspired a great deal of further work on Kantian moral and political philosophy in Britain and the United States and has also been influential in Germany, although there an independent version of Kantianism, the theory of Jürgen Habermas (1929–) that political principles should be chosen in an "ideal communicative situation" has also been widely influential.
See also Continental Philosophy ; Idealism ; Metaphysics ; Philosophy .
Beiser, Frederick C. The Fate of Reason: German Philosophy from Kant to Fichte. Cambridge, Mass.: Harvard University Press, 1987.
——. German Idealism: The Struggle against Subjectivism, 1781–1801. Cambridge, Mass.: Harvard University Press, 2002.
Bennett, Jonathan. Kant's Analytic. Cambridge, U.K.: Cambridge University Press, 1966.
Carnap, Rudolf. The Logical Structure of the World: Pseudoproblems in Philosophy. Translated by Rolf A. George. Berkeley: University of California Press, 1967.
——. Substance and Function; and, Einstein's Theory of Relativity. Translated by William Curtis Swabey and Marie Collins Swabey. Mineola, N.Y.: Dover Publications, 2003.
Guyer, Paul, ed. The Cambridge Companion to Kant. Cambridge, U.K., and New York: Cambridge University Press, 1992. A multiauthored introduction to main themes in Kant's philosophy with an extensive bibliography.
Habermas, Jürgen. Knowledge and Human Interests. Translated by Jeremy J. Shapiro. Boston: Beacon Press, 1971.
——. Moral Consciousness and Communicative Action. Translated by Christian Lenhardt and Shierry Weber Nicholsen. Introduction by Thomas McCarthy. Cambridge, Mass.: MIT Press, 1990.
——. The Theory of Communicative Action. Translated by Thomas McCarthy. Boston: Beacon Press, 1984–1987.
Herman, Barbara. The Practice of Moral Judgment. Cambridge, Mass.: Harvard University Press, 1993.
Hill, Thomas E., Jr. Dignity and Practical Reason in Kant's Moral Theory. Ithaca, N.Y.: Cornell University Press, 1992.
——. Human Welfare and Moral Worth: Kantian Perspectives. Oxford and New York: Oxford University Press, 2002.
——. Respect, Pluralism, and Justice: Kantian Perspectives. Oxford and New York: Oxford University Press, 2000.
Kant, Immanuel. The Cambridge Edition of the Works of Immanuel Kant. Edited by Paul Guyer and Allen W. Wood. 16 vols., 12 published as of 2004. Cambridge, U.K.: Cambridge University Press, 1992–. The standard English translation of all of Kant's published works as well as extensive selections from his lectures, correspondence, and posthumous material.
——. Kants gesammelte Schriften. Edited by the Royal Prussian, subsequently German, then Berlin-Brandenburg Academy of Sciences. 29 vols., 28 published as of 2004. Berlin: Georg Reimer, subsequently Walter de Gruyter and Co.: 1900–. The standard German edition of Kant's writings.
Köhnke, Klaus Christian. Entstehung und Aufstieg der Neukantianismus: Die deutsche Universitätsphilosophie zwischen Idealismus und Positivismus. Frankfurt am Main, Germany: Suhrkamp, 1986. Translated without endnotes as The Rise of Neo-Kantianism: German Academic Philosophy between Idealism and Positivism. Translated by R. J. Hollingdale. Cambridge, U.K., and New York: Cambridge University Press, 1991.
Korsgaard, Christine M. Creating the Kingdom of Ends. Cambridge, U.K., and New York: Cambridge University Press, 1996.
Lewis, Clarence Irving. Mind and the World-Order: Outline of a Theory of Knowledge. New York: Dover, 1956.
Nell (O'Neill), Onora. Acting on Principle: An Essay on Kantian Ethics. New York: Columbia University Press, 1975.
O'Neill, Onora. Constructions of Reason: Explorations of Kant's Practical Philosophy. Cambridge, U.K., and New York: Cambridge University Press, 1989.
Pinkard, Terry. German Philosophy 1760–1860: The Legacy of Idealism. Cambridge, U.K., and New York: Cambridge University Press, 2002.
Rawls, John. A Theory of Justice. Rev. ed. Cambridge, Mass.: Harvard University Press, 1999.
——. "Kantian Constructivism in Moral Theory." In his Collected Papers, edited by Samuel Freeman. Cambridge, Mass.: Harvard University Press, 1999.
Rickert, Heinrich. The Limits of Concept Formation in Natural Science: A Logical Introduction to the Historical Sciences. Edited and translated by Guy Oakes. Abridged ed. Cambridge, U.K., and New York: Cambridge University Press, 1986.
——. Science and History: A Critique of Positivist Epistemology. Translated by George Reisman. Princeton, N.J.: Van Nostrand, 1962.
Sellars, Wilfrid. Science and Metaphysics: Variations on Kantian Themes. London: Routledge and Kegan Paul, 1968.
Strawson, P. F. The Bounds of Sense: An Essay on Kant's "Critique of Pure Reason." London: Methuen, 1966.
Strawson, P. F. Individuals: An Essay in Descriptive Metaphysics. London: Methuen, 1959.
Willey, Thomas E. Back to Kant: The Revival of Kantianism in German Social and Historical Thought, 1860–1914. Detroit: Wayne State University Press, 1978.
Wood, Allen W. Kant. Malden, Mass.: Blackwell, 2005. An excellent short introduction to Kant's philosophy.