A Grammar of Thresholds: A Stratified Ontology from Physics to Life

This document proposes a stratified ontology that articulates, under a single conceptual grammar, what fundamental physics, autopoietic biology, and contemporary cognitive science say about reality at their different scales. The initial motivation arises from a gap in the contemporary metaphysical landscape: ontic structural realism illuminates physics but struggles to account for the living; process ontologies capture the dynamics of becoming but struggle to articulate their intuitions with contemporary scientific formalisms; formal ontologies provide tools for interoperability without settling fundamental metaphysical questions. The thesis defended here is that a sufficient grammar requires the distinction of a liminal threshold of existence and five levels of positive articulation: non-indifference (level 0), generative regimes of constraints (level 1), effective operative differences articulating counterfactual relevance and transductive actualization (level 2), structural stabilizations producing derived objects (level 3), and living autonomy, which unfolds along a gradient of extension of the accessible space of action - from the maintenance of internal constraints to the transmissible reconfiguration of biological constraints, through behavioral modulation, niche reconfiguration, and technical-symbolic extension (level 4). Living agentivity is formally characterized as a reweighting of admissible trajectories within generative regimes of constraints. The relation between levels is framed as stratified asymmetric dependence: each level presupposes the preceding ones without being reducible to them, and each transition is treated as an ontological threshold rather than denied as a problem. The architecture is tested through a case study crossing all levels: retinal phototransduction, from photon to conscious access. Finally, the document makes explicit, in an appendix, its cooperative human-AI mode of production as an element of methodological traceability.