 In 1871 Cohen published a long essay, “On the Controversy between Trendelenburg and Kuno Fischer,” and a book, the first edition of Kant’s Theory of Experience. They were both defenses of Kant against objections that Cohen thought badly misunderstood his views on objectivity and the a priori. Cohen was responding to an interpretation of Kant in the 1860s commonly held by figures of the Back-to-Kant movement such as Hermann von Helmholtz and Cohen’s own senior colleague at Marburg, F.A. Lange, as well as by non-Kantian philosophers such as Adolf Trendelenburg. Very roughly, these figures thought that Kant held (or that Kantian philosophers ought to hold) that the character of human knowledge is determined by both objective and subjective factors. On one hand, there are objects that exist independently of the subject’s mind. These objects affect the subject’s mind, and in so doing contribute the objective element to the subject’s representations. On the other hand, there are structures in the subject’s mind—say, the forms of human intuition, space and time. Because these structures are in the subject’s mind and thus don’t come from experience, they are a priori. Further, these a priori structures organize the subject’s representations and thereby contribute a subjective, mind-dependent element to them. But since on this interpretation of Kant the a priori is subjective, an explanation of knowledge’s objectivity must appeal not to it, but to the objects that exist independently of the mind.