Köln, Erzbischöfliche Diözesan- und Dombibliothek, 127, fol. 9rb (ca. 1160)

Ius generale nomen est, lex autem iuris est species. .  . Quid sit lex? Lex est constitutio scripta.

Huguccio (ca. 1190), D.1 c.3 s.v. Lex est constitutio scripta:  iustum precipiens et contrarium prohibens, ut xxiii. q.iiii. Si ecclesia (C.23 q.4 c.42).  Lex dicitur quia ligat, uel quia legatur utpote scripta, uel quia legitime agat dum sui obseruatores remunerat et transgressores plectit et mulctat, ut infra di. iii. Omnis et d.iiii. Facte (D.3 c.4 and D.4 c.1).  (commanding what is just and prohibiting what is unjust .  .  .  . Lex is called "lex" because it binds, or because it may be read as writing, or because it legitimately acts to reward those who observe lex and punishes and injures transgressors of lex.) Summa decretorum, 1: Distinctiones I-XX, ed. Oldřich Přerovský (Monumenta iuris canonici, Series A, 6; CittB del Vaticano: Biblioteca Apostolica Vaticana, 2006) 25.