This paper reexamines the relationship between Hermann Cohen of the Marburg School and Jakob Friedrich Fries and his successors, especially Ernst Friedrich Apelt, assessing it not as simple opposition but as an engagement marked by theoretical continuity and dialectical development. While Cohen has traditionally been understood as rejecting the Friesian School through his critique of "psychologism", this study interprets his intellectual development in this area as a "curious conceptual shift" and elucidates its inner logic. In the first edition of Kant's Theory of Experience, Cohen openly valued the epistemological contributions of Fries and Apelt, recognising their significance for the understanding of scientific cognition. Subsequently, however, in The Principle of the Infinitesimal Method and Its History and Logic of Pure Cognition, he moved away from psychological foundations towards a transcendental and logicist standpoint. Particularly in his interpretation of the infinitesimal, Cohen came to criticise the Friesian intuitive approach as lacking mathematical rigour and seeking to reconstruct scientific cognition through pure conceptual mediation. This paper argues that Cohen's critique often misread the Friesian position, especially regarding "intuition" and "induction". For Fries and Apelt, induction was not an empirical generalisation but a form of reasoning that derives hypothetical laws from observed facts-closely akin to Peircean abduction-thus mediating between theory and experience through a distinctive logical process. Cohen's disciple Paul Natorp critically adopted Apelt's concept of induction as a logic of hypothesis formation: for Natorp, deduction and induction (or abduction) functioned complementarily, allowing thought and science to advance according to the same law, a development that completed Marburg logicism. Thus, the question Cohen left unresolved, "How are hypotheses formed?" was partially addressed through Natorp's engagement with Friesian thought. In sum, Cohen's critique of the Friesian School was not a simple rejection but a selective reinterpretation and assimilation. His anti-psychologism aimed to purify the philosophical method, yet Friesian insights persisted within his framework.
Fumitaka SHIMOYAMA (Wed,) studied this question.