To the fourth one proceeds thus. It seems that moral virtue is able to be without the intellectual. For moral virtue, as Tully says, is habitude in the way of nature, agreeing [consentaneus] with reason. But even if nature agrees with some superior moving reason, it is not needful for that reason to be united with nature in the same thing, as is obvious in natural things lacking cognition. Therefore there is able to be in the human being moral virtue in the way of nature, inclining to agreement with reason, although that human being's reason is not completed through intellectual virtue.Further, through intellectual virtue a human being achieves complete use of reason. But it sometimes happens that those in whom the use of reason is not vigorous are virtuous and accepted by God. Therefore it seems that moral virtue can be without intellectual virtue.Further, moral virtue makes an inclination to working well. But some have a natural inclination to working well, even without the judgment of reason. Therefore moral virtues can be without intellectual virtues.But contrariwise is what Gregory says, in Moral. XXII, that other virtues, unless they act prudently in that for which they strive, are not able to be virtues. But prudence is an intellectual virtue, as was said above. Therefore moral virtues are not able to be without the intellectual.I reply that it must be said that moral virtue is able to be without certain intellectual virtues, like wisdom, knowledge, and craft, but it cannot be without intellection and prudence. Moral virtue is not able to be without prudence because moral virtue is choosing habitude, that is, one making good choice. But for choice to be good, two things are required. First, that there be due intending of the end, and this is done through moral virtue, which inclines the striving impulse to good appropriate to reason, which is the due end. Second, that the human being rightly receive those things that are endward, and this cannot be done save by reason rightly deliberating [consiliantem], judging, and prescribing, which pertains to prudence and to virtues annexed to it, as was said above. Therefore moral virtue is not able to be without prudence. And consequently neither without intellection. For by intellection naturally cognized principles are recognized, both in reflective and in working matters. Thus just as right reason in reflective matters, inasmuch as it proceeds from naturally cognized principles, presupposes intellection of principles, so also prudence, which is right reason for enactables.To the first it must be said that natural inclination in things lacking reason is without choice, and therefore such inclination does not necessarily require reason. But inclination of moral virtue is with choice, and thus for its completion it needs that reason be completed through intellectual virtue.To the second it must be said that in the virtuous the use of reason does not need to be vigorous with respect to everything but only with respect to those things that are done according to virtue. And thus use of reason is vigorous in all the virtuous. Thus those who seem to be simple, as lacking worldly wisdom [mundana astutia], are able to be prudent; according to Matth. X, Be prudent as serpents and simple as doves.To the third it must be said that natural inclination to the good of virtue is a sort of incipience [inchoatio] of virtue, but is not completed virtue. For this kind of inclination is insofar as it is stronger is able to be more dangerous, unless right reason is adjoined to it, through which is made right choice of those things appropriate to due end, just as a running horse, if blind, more forcefully stumbles and is injured the more forcefully it runs. And therefore even if moral virtue is not right reason as Socrates said, yet it is not only according to right reason inasmuch as it inclines to that which is according to right reason, as the Platonists held, but it must be with right reason, as Aristotle says in Ethic. VI.
[Thomas Aquinas, ST 2-1.58.4, my translation. The Latin is here, the Dominican Fathers translation is here.
