Constraint-Based Ontology

This work develops a constraint-based framework for evaluating ontological candidates by integrating three independently motivated domains: physical structure, normativity, and practical-historical irreversibility. Rather than advancing a positive ontology, the argument proceeds by coordinated restriction, identifying which models remain admissible once these domains are jointly treated as explananda. The central result is a closure claim concerning the non-preservability of identity-indexed normative reasons under structurally invariant transformations (PNS*), together with constraints on composability and evaluability. Within the restricted model space, the framework yields a conditional requirement for a unifying condition without committing to a fully specified ontology. The approach is explicitly non-totalizing and abductive. It combines eliminative constraints with comparative evaluation criteria, and situates its results in relation to debates in philosophy of physics, normativity, and metaphysical methodology. The preference for a Logos-type unifying condition is presented as conditional and revisable. Version 2.0 (canonical dossier). Subsequent revisions will be versioned.