But we use the word know ( ἐπίστασθαι ) in two different senses: he who has knowledge which he is not now using is said to know a thing, and also he who is now using his knowledge. Having knowledge, therefore, which is not now present to the mind, about what one ought not to do, will be different from having knowledge which is now present. Only in the latter sense, not in the former, does it seem strange that a man should act against his knowledge.

Again, since these reasonings involve two kinds of premises [a universal proposition for major and a particular for minor], there is nothing to prevent a man from acting contrary to his knowledge though he has both premises, if he is now using the universal only, and not the particular; for the particular is the thing to be done.