Kant, Immanuel (1724–1804)

1. Life and works

Immanuel Kant was born on 22 April 1724 in Königsberg, the capital of East Prussia. He was the child of poor but devout followers of Pietism, a Lutheran revival movement stressing love and good works, simplicity of worship, and individual access to God. Kant’s promise was recognized by the Pietist minister Franz Albert Schultz, and he received a free education at the Pietist gymnasium. At sixteen, Kant entered the University of Königsberg, where he studied mathematics, physics, philosophy, theology, and classical Latin literature. His leading teacher was Martin Knutzen (1713–51), who introduced him to both Wolffian philosophy and Newtonian physics, and who inspired some of Kant’s own later views and philosophical independence by his advocacy of physical influx against the pre-established harmony of Leibniz and Wolff. Kant left university in 1746, just as the major works of the anti-Wolffian Pietist philosopher Christian August Crusius were appearing. Kant’s upbringing would have made him receptive to Crusius, and thus he left university imbued with the Enlightenment aims of Wolffian philosophy but already familiar with technical criticisms of it, especially with Crusius’s critique of Wolff’s attempt to derive substantive conclusions from a single and merely formal first principle such as the logical principle of non-contradiction (see Wolff, C.).

On leaving university, Kant completed his first work, Thoughts on the True Estimation of Living Forces (1746, published 1749), an unsuccessful attempt to mediate between Cartesian and Leibnizian theories of physical forces. Kant then worked as a tutor, serving in households near Königsberg for the next eight years. When he returned to the university in 1755, however, he had several works ready for publication. The first of these was Universal Natural History and Theory of the Heavens, a much more successful scientific work than his first in which Kant argued for the nebular hypothesis, or origin of the solar system out of a nebular mass by purely mechanical means. The book was scarcely known during Kant’s lifetime, however, so the French astronomer Pierre Laplace (1749–1827) developed his version of the nebular hypothesis (published 1796) independently, and the theory became known as the Kant-Laplace hypothesis only later. In 1755, Kant also published two Latin works, his MA thesis A brief presentation of some thoughts concerning fire, and his first philosophical work, A new elucidation of the first principles of metaphysical cognition, which earned him the right to offer lectures at the university as a Privatdozent paid directly by his students. The following year Kant published The employment in natural philosophy of metaphysics combined with geometry, of which sample I contains the physical monadology, which made him eligible for a salaried professorship, although he was not to receive one until 1770. In these years, Kant also published four essays on earthquakes and winds.

Kant began lecturing in the autumn of 1755, and to earn a living lectured more than twenty hours a week. His topics included logic, metaphysics, ethics, and physics, and he subsequently added physical geography, anthropology (Germany’s first lectures so entitled), pedagogy, natural right and even the theory of fortifications. Except for one small essay on optimism (1759), he did not publish again until 1762, when another burst of publications began. He then published, all in German: The False Subtlety of the Four Syllogistic Figures (1762); The Only Possible Argument in support of a Demonstration of the Existence of God and Attempt to Introduce the Concept of Negative Magnitudes into Philosophy (1763); Observations on the Beautiful and Sublime and Inquiry concerning the Distinctness of the Principles of Natural Theology and Morality (1764), the latter of which was his second-place entry in a competition won by Moses Mendelssohn; Dreams of a Spirit-Seer, elucidated by Dreams of Metaphysics (1766); and Concerning the Ultimate Ground of the Differentiation of Directions in Space (1768). These publications earned Kant widespread recognition in Germany. During this period, Kant was deeply struck by the work of Jean-Jacques Rousseau, especially by his Social Contract and the paean to freedom in Émile (both 1762). By this time Kant was also acquainted with the philosophy of David Hume, whose two Enquiries and other essays, but not A Treatise of Human Nature, were published in German as early as 1755.

Having unsuccessfully applied for several chairs at home while declining offers elsewhere, Kant was finally appointed Professor of Logic and Metaphysics in Königsberg in 1770. This event occasioned his inaugural dissertation, and last Latin work, On the form and principles of the sensible and intelligible world. Following correspondence about this work with Johann Heinrich Lambert, Johann Georg Sulzer, and Mendelssohn, however, Kant fell into another decade-long silence, broken only by a few progress reports to his recent student Marcus Herz and a few minor essays. Yet during this ‘silent decade’, Kant was preparing for his enormous body of subsequent works. Beginning in 1781, with the first edition of the Critique of Pure Reason, Kant unleashed a steady torrent of books. These include: Prolegomena to Any Future Metaphysics that shall come forth as Scientific, an attempted popularization of the first Critique, in 1783; two essays, ‘Idea for a Universal History from a Cosmopolitan Point of View’ and ‘What is Enlightenment?’ in 1784; The Groundwork of the Metaphysics of Morals and four other essays in 1785; The Metaphysical Foundations of Natural Science, essays on ‘The Conjectural Beginnings of Human History’ and ‘What Does it mean to Orient Oneself in Thinking?’ and two other pieces in 1786; a substantially revised second edition of the Critique of Pure Reason in 1787; in 1788, the Critique of Practical Reason and an essay on ‘The Use of Teleological Principles in Philosophy’; the Critique of Judgment as well as an important polemic ‘On a discovery according to which any new Critique of Pure Reason is rendered dispensable by an older one’ in 1790; the political essay ‘On the Common Saying: "That may be right in theory but does not work in practice"’ and the controversial Religion within the Limits of Reason Alone in 1793; Towards Perpetual Peace in 1795; the Metaphysics of Morals, comprising the ’Doctrine of Right’ and the ’Doctrine of Virtue’, in 1797, as well as the essay ‘On a putative Right to Lie from Love of Mankind’; and his last major works in 1798, a handbook on Anthropology from a Pragmatic Point of View and his defence of the intellectual freedom of the philosophical faculty from religious and legal censorship in the restrictive atmosphere of Prussia after Frederick the Great, The Conflict of the Faculties. (With Kant’s approval, some of his other lecture courses were also published, including Logic in 1800 and Physical Geography and Pedagogy in 1804.) Kant retired from lecturing in 1797, at the age of seventy-three, and devoted his remaining years to a work which was to be entitled ‘The Transition from the Metaphysical First Principles of Natural Science to Physics’, but which was far from complete when Kant ceased working on it in 1803. (Selections from his drafts were first published in 1882–4, and they were first fully published as Opus postumum in 1936–8). After a lifetime of hypochondria without any serious illness, Kant gradually lost his eyesight and strength and died 12 February 1804.