Kant’s Prolegomena -- its full title, in the eighteenth-century manner, is Prolegomena to Any Future Metaphysics Which Will Be Able to Come Forth as Science -- is a classic in metaphysics and the theory of knowledge. It deals with the perennially baffling questions: How do we know? How much can we know? Its answers to these questions are interesting especially now. We live in one of the recurring periods of intellectual and cultural history that are skeptical and impatient of systems of speculative metaphysics, and a distrust of speculation is the leading motif of the Prolegomena. Though Kant's arguments against speculative metaphysics differ from those of our contemporaries, in some of his results he anticipates their negative conclusions. The Prolegomena, however, is not interesting merely as an historical anticipation of recent views; indeed, as such it has been as it were condemned in advance by Kant (Prolegomena, Introduction). Rather, its chief interest to the student of philosophy is probably the way in which it goes beyond and against the views of contemporary positivism. The book is therefore a challenge both to those who think metaphysical knowledge of the ultimate nature of things is possible and to those who regard metaphysics as comprising only pious wishes and rationalizations, “poetry”, "nonsense," and "pseudoproblems." The Prolegomena is, moreover, the best of all introductions to that vast and obscure masterpiece, the Critique of Pure Reason. It is a guide through what Kant himself calls the "thorny paths" of that work. Because of the central position the Critique occupies in philosophy, the Prolegomena thus makes a major contribution to an understanding of the chief problems of general philosophy, metaphysics, theory of knowledge, philosophy of science, and ethics. It has an exemplary lucidity and wit, making it unique among Kant's greater works and uniquely suitable as a textbook of the Kantian philosophy.