Thus far we have expounded by the letter; but metaphorically, as we often find gold put for the sense, silver for the words, brass for the voice - all these we may say we are not to receive from others, but to have them given by the Lord. We are not to take up the teaching of heretics, of philosophers, and of corrupt doctrine.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).