The vault's source-tier apparatus revives the système de preuve légale the Enlightenment abolished — the same graded-proof machine, run in reverse to bind an AI reasoner

The medieval Roman-canon law of proofs and the vault's own source-discipline apparatus turn out to share not a loose "both grade evidence" resemblance but a tight structural isomorphism, feature for feature. The medieval regime fixed the probative weight of each evidence-type in advance (claim-roman-canon-law-rated-one-witness-equal-to-a-private-document); the vault fixes weight by a five-tier rubric and a sourcing floor keyed to claim-type. The medieval regime named an explicit intermediate — the probatio semi-plena, a half-proof short of conviction; the vault names capture-verified, an intermediate short of verified-verbatim (claim-gersick-1991-deep-structure-quotes-confirmed-verbatim). Both encode an independence rule: Roman-canon proof required two witnesses to the same fact, and the vault explicitly refuses a cross-model re-read of the same mirror as corroboration — a second reader of one carrier is "one witness in disguise," the same defect observation-suspicious-perfection-independence-absence-signals-defect names as the missing-independence signature.

The sharp point is the inversion of the trust-target. The Enlightenment abolished the fixed proof-rules in order to free the fact-finder's conviction — intime conviction, trusting a human reasoner over rigid law (claim-french-revolution-abolished-preuve-legale-for-intime-conviction). The vault reimposes fixed proof-rules in order to bind the conviction of its reasoner — because that reasoner is an LLM prone to hallucination. Same apparatus, opposite direction of trust: the medieval court trusted its judge more than its rules and had the rules imposed on it anyway; the vault trusts its reasoner less than the medieval court trusted its judge, and rebuilds the abolished machine on purpose. The vault runs the Enlightenment backwards.

This is distinct from, and the whole-architecture complement of, the independence-only reading in observation-suspicious-perfection-independence-absence-signals-defect: that note isolates the single rule (evidence without independent origin is defective); this one observes that the vault has reinstated the entire graded-proof regime — tiers, floor, named intermediate, and independence rule together — and reversed its purpose. The graded system's refusal to quantify further (claim-medieval-proof-law-graded-evidence-but-refused-to-quantify-it) has its vault echo too: discrete tiers and statuses, never a continuous confidence score.