Kant's Prolegomena, although a small book, is without doubt the most important of his writings, writes the translator, Paul Carus.

Prolegomena means, literally, prefatory or introductory remarks, and it furnishes us with a key to his main work, The Critique of Pure Reason; in fact, it is an extract containing all the salient ideas of Kant's system. It approaches the subject in the simplest and most direct way and is therefore best adapted as an introduction into his philosophy. It is not without good reasons that the appearance of the Critique of Pure Reason is regarded as the beginning of a new era in the history of philosophy; and so it seems that a comprehension of Kant's position, whether we accept or reject it, is indispensable to the student of philosophy. It is not his solution which makes the sage of Königsberg the initiator of modern thought, but his formulation of the problem.