In situating Nishida Kitarō’s recurring engagements with topics in modern physics, one may find it difficult to avoid the overwhelming impression that his system of philosophy is metaphysical insofar as it stands aloof of empirical settings. At the same time, it positions empirical observers within an interactively dialectical locus or “situational matrix” (basho 場所) of abstract contradictory pairs. As Nishida develops his theory of the situation (basho), he gathers supporting concepts for strengthening coherent correspondences between his concept of situation and various concepts of fields, including complementarity in Niels Bohr, the operationalism of P. W. Bridgman, and the world-lines of Hermann Minkowski, not to mention his use of Poincaré’s approach to group theory. This chapter explores the divergence between Nishida and Tanabe Hajime, particularly the latter’s mediation-oriented philosophy, which contrasts with Nishida’s focus on absolute nonbeing. Nishida’s dynamic philosophical rigor avoids rigid categorization, incorporating subjective participation as is also requisite in quantum mechanics. Though Nishida himself tried to establish a “concrete logic”, this chapter highlights the limits of Nishida’s reliance on a pure, abstract dialectic centered on absolute nonbeing, in contrast with Marxian materialist dialectics in Tosaka Jun, which nevertheless influenced both Nishida and Tanabe.