Failure Mode Classification Epistemic vs Non Epistemic

This paper provides an exhaustive, non-procedural classification of failure modes into epistemic and non-epistemic classes under admissibility and standing constraints. Epistemic failures are shown to arise from violations of admissibility—such as illicit redescription, scope transport, or standing loss—while non-epistemic failures correspond to ordinary implementation, resource, or execution breakdowns that carry no standing implications. The analysis is strictly declarative and eliminative: it introduces no diagnostic algorithms, recovery procedures, or mitigation strategies. By fixing this distinction on record, the paper closes a widespread explanatory confusion in physics, mathematics, and AI governance, and establishes that only epistemic failures are relevant to legitimacy, while all non-epistemic failures are semantically and ontologically inert at the governance boundary.