Widely considered the foremost philosopher since classical antiquity, Immanuel Kant effected a revolution in philosophy. His influence on the development of science, theology, and philosophy is virtually incalculable. He offered solutions to problems that have always had the utmost relevance for the thinker: What are morality and duty? What are truth, beauty, and justice? What can and cannot be known? He clarified the difference between knowledge and faith and established the limits of each; in so doing, he liberated science from religion and religion from science. Then he freed individual conscience from outside authority by placing morality in the disposition of the individual heart. In addressing these and other problems, he terminated the one-sided intellectualism of the eighteenth century. Virtually all thinkers since then who have seriously tackled the fundamental principles in science, theology, and philosophy have done so by starting with ideas first developed by Kant.

Kant...