Immanuel Kant’s Critique of Pure Reason is an established classic in the history of epistemology. First published in 1781 and then revised in 1787, it is the fruit of Kant’s later years and, as such, clearly reflects the insight and wisdom of a mature mind. It is a work in which the author attempted to conciliate two conflicting theories of knowledge current at his time: British empiricism as represented by John Locke, George Berkeley, and David Hume, and continental rationalism as represented by René Descartes, Gottfried Wilhelm Leibniz, and Christian von Wolff. The latter theory maintained that important truths about the natural and the supernatural worlds are knowable by pure reason alone, independently of perceptual experience, whereas the former held that perceptual experience is the source of all our legitimate concepts and truths of the world. Kant believed that both these doctrines were wrong, and he tried in Critique of Pure Reason to correct the pretensions of each while saving what was sound in each.