This volume is the first part of a larger work on the philosophy of Solomon Maimon and its systematic place in the history of thought. Here we deal with so me of the fundamental themes of Maimon’s philosophy, including his examination of Kant’s philosophy, his re lation to such immediate post-Kantians as Reinhold and Schulze, and the relation between him and Fichte. The second volume will concern itself with such aspects of Maimon’s theoretical philosophy as the prob lem of the categories, the relation between idea and fiction, the concept of a universal soul, and practical philosophy, that is, ethics and the philosophy of law. Chapters V, VII, and X of this volume contain, with substantial revisions in form and content, material that appeared originally in scholarly periodicals. Grateful acknowledgment is made to the Hebrcw Union College A nnual for permission to use the substance of my articles: Solomon Maimon’s Treatment of the Problems of Antinomies and Its Relation to Maimonides, H.U.C.A., Vol. XXI; Maimon and Mai monides, H.U.C.A., Vol. XXII, part one; and to the Journal 0/ the History 0/ I deas, for permission to use the substance of my essay Solomon Maimon’s Doctrine of Infinite Reason and Its Historical Relations, J.H.I., Vol. XIII, No. 2.