Following his university studies, Kant worked as a private tutor to wealthy
families. By 1755, he was back in the university, where he was employed as an
unsalaried lecturer for the next fifteen years. (Given the difficulty of his writing, it is
worth noting that his lectures were very popular.) His early lectures focused on the
external world, dealing with issues in physics and physical geography. He published
an important early work,Universal History of Nature and Theory of the Heavens
(1755), which explained the structure of the universe in terms of Newtonian physics,
without reference to God. During this period, Kant’s focus began to shift to the inner
world of the mind and the nature of morality. At this time, he also encountered the
writings of Hume, which challenged the rationalism he had imbibed from Wolff. He
later said that Hume “interrupted my dogmatic slumber, and gave my investigations
in the field of speculative philosophy quite a new direction.”
In 1770, Kant was given what he had long desired—the chair of logic and
metaphysics at the University of Königsberg. In his inaugural address,
Dissertation on the Form and Principles of Sensible and Intelligible Worlds,
Kant declared his intention to reconstruct philosophy. Over the next ten years,
he carefully and quietly thought through all his ideas. Finally he wrote his
major work,Critique of Pure Reason. He wrote it, as he later told a friend,
“within four or five months, with the utmost attention to the contents, but with
less concern for the presentation or for making things easy for the reader.”
Unfortunately, when the book appeared, his indifference to readers left most
people lost. In 1783, he restated his main points in a work “for the benefit of
teachers,” the Prolegomena to Any Future Metaphysics,and in 1787 he rewrote
the Critiqueitself.
Kant’s first major work on ethics,Foundations of the Metaphysics of Morals,
was published in 1785. A further development of his moral views,Critique of
Practical Reason,appeared in 1788. In 1790, Kant published his third and last
critique, the Critique of Judgment,which deals with aesthetic judgments and the
question of purpose in nature. Kant’s other important works include Metaphysical
Foundations of Natural Science(1786),Religion Within the Limits of Reason
Alone(1793),Toward Eternal Peace(1795), and Foundations of the Metaphysics
of Morals(1797).
Whereas Kant’s writings revolutionized the philosophical world, his personal
life was quiet, almost boring. With one minor exception late in life, he was never
involved in any scandals or controversies. He never traveled more than a few
miles outside Königsberg. A lifelong bachelor, he is said to have awakened and
gone to bed at exactly the same time each day. His daily walks were reportedly so
regular that people could set their clocks by his approach. A rather frail man, he
so carefully guarded his health that he lived a long, productive life. Yet he was
also a delightful conversationalist and host, and he had many friends and admir-
ers. At his death in 1804, he was the best-known philosopher in Germany, read, if
not understood, throughout Europe.
Responding to the skeptical empiricism of Hume, Kant argued that the mind is
not simply a repository of impressions and ideas but it is actively involved in
knowing the objects it experiences. Prior to Kant, most thinkers believed that the
mind, in knowing, conformed to objects: that the ideas of the mind took on the
776 IMMANUELKANT
