On good will

“A MAN is not called good or bad on account of his capabilities but on account of his actions, that is, not because he is able to act well but because he does in fact act well. When a man understands perfectly he becomes able to act well. Thus one who has the habit of grammar is able to speak correctly, but that he actually speak correctly he must will it. The reason is that a habit is that quality by which a person acts when he wishes, as the Commentator says in the third book De Anima. It is obvious then that good will makes a man act well according to every capability or habit obedient to reason.

“Therefore a man is called good simply because he has a good will. However, from the fact that he has a good intellect he is not good simply but relatively good, for example, a good grammarian or a good musician. Therefore, since choice pertains to the will but opinion to the intellect, we are called good or bad by reason of choice but not by reason of opinion.”

~St. Thomas Aquinas: Commentary on Aristotle’s Nicomachean Ethics, Bk. III, Lect. VI, 451.

Aristotle, Ethica ad Nicomachum, by Gaspare da Padova.
Manuscript, c. 1470; Biblioteca Historica, Universitat de Valencia, Valencia.