Aside from Herbart’s textbook presentation of traditional logic (e.g., Section II of LEP), his main logical innovation is his so-called method of relations, devised as an organon for correct metaphysical thinking (SW V: 201, f.). The metaphysical problems it aims to address include: the thing as (one) substance with (many) characteristics; causality; matter; and the ego. He considers these problematic because they give rise to an empirically given, yet self-contradictory concept (Weiss 1928: 37). Due to space constraints, we will here only briefly touch on the problems of thing and ego, the former for its role in the development of apperception, the latter because it is grounds his psychology. Both his idea of metaphysics and the method of relations will become clearer as we see them used to explain concrete psychological phenomena in Section 3.