D1 The Epistemic Firewall

This paper establishes the existence and necessity of an epistemic firewall within a closed admissible framework. It proves that a strict boundary must separate admissible reasoning from illicit scope transport, such that violations are fail-closed rather than repaired, deferred, or absorbed. The firewall is not a mechanism, procedure, or enforcement tool, but a structural consequence of standing conservation and closure by exhaustion. Attempts to bypass, soften, or externalize this boundary are shown to collapse admissibility by reintroducing hidden authority or deferred validation. The analysis is strictly eliminative and non-constructive: it introduces no new primitives, specifies no procedures, and provides no operational interpretation. The result functions as a boundary theorem, fixing the firewall as a necessary condition for admissible reasoning rather than a design choice.