As assertion and denial are to thought, so pursuit and avoidance are to desire. Now virtue of character is a state that decides; and decision is a deliberative desire. If, then, the decision is excellent, the reason must be true and the desire correct, so that what reason asserts is what desire pursues.
[I]f what is good and healthy for human beings and for fish is not the same, whereas what is white or straight is always the same, everyone would also say that the content of wisdom is the same in every case, but the content of prudence is not. For the agent they would call prudent is the one who studies well each question about his own [good], and he is the one to whom they would entrust such questions. That is why prudence is also ascribed to some of the beasts, the ones that are evidently capable of forethought about their own life.
[O]ur deliberation may be either good without qualification or good only to the extent that it promotes some [limited] end. Hence unqualifiedly good deliberation is the sort that correctly promotes the unqualified end [i.e., the highest good], while the [limited] sort is the sort that correctly promotes some [limited] end.