Cologne, Dombibliothek 127, fol. 18v

Gratian, Distinctions 19 and 20

C.19, Dictum before chapter (d.a.c.) 1: There is a question whether decretal letters have authoritative force because they do not appear in the corpus of canons.

D.20 d.a.c.1: Decretal letters are legally the same as the canons of councils.  The last question is whether the writings of the Church Fathers are equal to the canons and decretals or are preferred to them.