P23: A man cannot absolutely be said to act from virtue insofar as he is determined to do something because he has inadequate ideas, but only insofar as he is determined because he understands.

Dem.: Insofar as a man is determined to act from the fact that he has inadequate ideas, he is acted on (by IIIP1), i.e. (by IIID1 and D2), he does something which cannot be perceived through his essence alone, i.e. (by D8), which does not follow from his virtue.

But insofar as he is determined to do something from the fact that he understands, he acts (by IIIP1), i.e. (by IIID2), does something which is perceived through his essence alone, or (by D8) which follows adequately from his virtue, q.e.d.