A Life Measured in Footsteps
Immanuel Kant was born in 1724 in Konigsberg, East Prussia, the son of a saddler, and raised in austere Pietist piety that he later remembered with respect and relief at his escape. He never traveled more than a hundred miles from home. After his father's death he spent years as a private tutor, then climbed slowly through the university, not gaining his professorship until 1770, at forty-six. Legend says citizens set their watches by his afternoon walk; like most Kant legends it flattens a man who was, by contemporary accounts, a witty host who loved conversation, dinner parties, and billiards.
His early work was scientific: a nebular theory of the solar system's origin that anticipated later astronomy, essays on earthquakes and winds. Then David Hume, he said, woke him from his dogmatic slumber. If Hume was right, causation itself was habit, and science rested on nothing. Kant spent a silent decade assembling his answer, and in 1781, at fifty-seven, published the Critique of Pure Reason, a book so dense that even sympathetic readers begged for a summary. He obliged, twice, and kept revising. Philosophy has been metabolizing the result ever since.
The Copernican Turn
Kant's proposal reversed the ancient picture: instead of the mind conforming to objects, objects conform to the mind. Space, time, and causality are not features we passively receive but the very lenses through which any experience must come. We can therefore have certain knowledge of the world as it appears, never of things as they are in themselves. With one stroke he rescued Newtonian science from Hume's acid and demolished centuries of confident metaphysics about God and the soul, relocating both beyond knowledge, in the territory of rational faith.
His ethics matched the architecture. The Groundwork of 1785 argued that morality cannot rest on consequences or feelings, which vary, but only on a law reason gives itself: act only on principles you could will as universal law, and treat humanity, in yourself and others, never merely as a means. Dignity, in Kant's strict sense, is what has no price. His 1784 essay on Enlightenment gave the age its motto, sapere aude, dare to know, and his Perpetual Peace of 1795 sketched a federation of republics that later generations read as a blueprint for the League of Nations and the United Nations.
The Unfinished Kant
The record has stains that scholarship no longer ignores. In his lectures on geography and anthropology Kant taught a hierarchy of races with Europeans at the summit, statements flatly at odds with his own universalism; some scholars find evidence he retreated from these views late in life, others see no clean repentance. He also bowed, resentfully, to Prussian censorship, promising the king in 1794 to stop writing on religion, a promise he considered void when the king died. The philosopher of autonomy knew the taste of compliance.
He died in 1804, his powers long faded, reportedly murmuring that it is good. His tomb by Konigsberg cathedral, in what is now Kaliningrad, carries the sentence about the starry heavens above and the moral law within that still draws visitors. Every philosophical movement since, German idealism, analytic philosophy, human rights law, has defined itself with or against him. The insistence that persons are ends in themselves, never mere instruments, may be the single most consequential sentence of modern ethics, written by a man who never saw the sea.
