From the Success of L1 to the Necessity of L0

This paper examines a recurrent structural tension that arises when successful explanatory frameworks confront problems concerning totality. Within well-defined domains, L1-level inquiry—whether metaphysical, epistemological, or linguistic—can achieve high degrees of precision and systematic coherence[1]. However, when the object of explanation shifts from entities within a domain to the domain as a whole, a different type of difficulty emerges. A diagnostic comparison of three recurrent historical strategies reveals a common pattern. One strategy terminates regress by introducing an ultimate explanatory anchor. A second preserves the boundary of cognition while retaining a reserved “outside.” A third acknowledges limits and responds with silence. Each strategy represents a serious and sophisticated attempt to address totality questions. Yet structurally, they operate with tools appropriate to domain-internal explanation. The recurrence of these strategies across philosophical traditions suggests that the difficulty is not individual or doctrinal, but structural. When totality is treated as an object within explanatory space, L1 operations encounter inherent limits. This paper argues that the necessity of an L0-level operation follows from this pattern. L0 is not proposed as a superior doctrine, but as a distinct structural layer required for handling totality problems without reintroducing external anchors, preserved outsides, or silent remainders. The argument proceeds diagnostically rather than polemically. It does not negate the achievements of L1 inquiry; rather, it clarifies the structural conditions under which its success generates the need for an additional level of analysis. [1] In this paper, “L1” designates domain-internal explanatory operations—analysis conducted within a determinate field of entities, relations, or structures. “L0” designates a structural layer concerned with the admissibility conditions of such operations. The distinction is functional rather than hierarchical and is introduced here for analytical clarity.