Diplomatics joined the 19th-century Rankean historian's toolkit as an auxiliary science — institutional convergence, not proof Ranke's method derived from Mabillon

Wikipedia's "Diplomatics" article describes the discipline, founded by [[claim-mabillon-1681-founded-diplomatics-to-refute-forgery-charge|Mabillon's 1681 De re diplomatica]], as "one of the auxiliary sciences of history," with techniques closer to textual and historical criticism than to narrative history-writing. Wikipedia's "Auxiliary sciences of history" article states that as empirical source-based history spread — first via the late-18th-century Göttingen school, then via Leopold von Ranke from the mid-19th century onward — disciplines including diplomatics and paleography came to be regarded as part of the trained historian's standard skill-set.

This documents institutional absorption: Rankean professionalizing historiography took up an already-existing auxiliary science, diplomatics among them. It is not evidence that Ranke's own critical method was intellectually derived from Mabillon specifically, as opposed to arriving independently at document-based verification and later folding diplomatics in alongside it. A direct check of Wikipedia's "Historical method" article found no mention of Mabillon or diplomatics at all — negative evidence against a clean single-line-of-descent reading. This keeps question-verify-diplomatics-to-priority-adjudication-descent at methodological analogy for the Ranke leg specifically, even as a different, earlier route shows the underlying method did travel somewhere, directly and by name.