This, I believed, meant either that certain propositions of constitutional law functioned as modalities, determining the truth of other propositions, but were themselves indeterminable as to this truth, or that some external structure validated these propositions. If it was the former, then their legitimacy derived from their use alone, and from nothing else.

DEFINE: Distinguishes two ways legal propositions acquire validity: internal modality or external structure. Builds on: "Legitimacy can derive from existing practices rather than external justifications."

Philip Chase Bobbitt, Philip Chase Bobbitt - Refl…, loc. 59