This article considers early Schopenhauer’s polemic against Kant's epistemology and views on the objectives and methods of philosophy. The crucial influence of this polemic and Kant’s works on the development of Schopenhauer’s philosophy is stressed. The author investigates Schopenhauer’s reception of the above aspects of Kant’s philosophy in 1811—1813 and its later evolution. For this purpose, the author addresses Schopenhauer’s manuscripts (early philosophical aphorisms and comments and marginal notes on Kant’s works, etc.), as well as the first edition of Schopenhauer’s doctoral dissertation On the Fourfold Root of the Principle of Sufficient Reason (1813). The mentioned influence of Kant’s philosophy on Schopenhauer and its decisive rol...