Some commentators on Hermann Cohen have remarked on what they take to be a puzzle about the origins of his mature anti-psychologism. When Cohen was young, he studied a kind of psychology, the Völkerpsychologie of Moritz Lazarus and Heymann Steinthal, and wrote apparently psycholgistic accounts of knowledge almost up until the moment he first articulated his anti-psychologistic neo-Kantianism. To be sure, Cohen's mature anti psycholgism does constitute a rejection of certain central commitments of Völkerpsychologie. However, the relation between Völkerpsychologie and Cohen's mature anti-psychologism is not one of straightforward opposition. This paper argues that Cohen had significantly less distance to travel than it appears to get from his early Völkerpsychologie to his mature anti-psychologism. In particular, this paper argues that Cohen always had an anti-psychologistic account of knowledge, even during the period when he was studying Völkerpsychologie, and further, that key features of his Völkerpsychologie partly shaped his mature account of knowledge. Finally, the paper identifies how Cohen’s views did change over the transition from his völkerpsychological period to his later anti-psychologism. It thus identifies what changes in Cohen’s views do need to be explained.