We would ask those heretics who affirm that there are two natures directly opposed to each other, if they admit that a good tree cannot bring forth evil fruit, how it was possible for Moses, a good tree, to sin as he did at the water of contradiction? Or for Peter to deny his Lord in the Passion, saying, “I know not the man?” Or how, on the other hand, could Moses’ father-in-law, an evil tree, inasmuch as he believed not in the God of Israel, give good counsel?
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).