More commonly, however, the indeterminacy to be filled by a decisionmaker's choice is not pervasive throughout the range of applications of a term. Instead, the indeterminacy is encountered only at the edges of a term's meaning. As H.L.A. Hart tells us, legal terms possess a core of settled meaning and a penumbra of debatable meaning.

XREF: Connects to H.L.A. Hart's concept of the open texture of law in The Concept of Law. Pays off: "Formalism wrongly treats legal terms as self-contained categories."

Frederick Schauer, Frederick Schauer - Formali…, loc. 37