Article I: On Intellectual Virtues

St. Thomas, I-II, q. 57; De Virt. q. 1, a. 6 and 7.

588. Principle. Five distinct species of intellectual virtues are enumerated:

A. Three are in the speculative intellect, which rests in the contemplation of truth, by which namely it is perfected for knowing truth:

1. The habit of principles, by which it is disposed for knowing first principles, whether speculative, and then it is called simply understanding (nous), or practical, and then it is called synderesis.

2. Science (episteme), by which it is perfected for knowing evident conclusions in some genus of knowable things through their proper causes.

3. Wisdom (sophia), by which it is perfected for knowing conclusions of whatever genus through the highest causes, through which it also judges concerning principles.

B. In the practical intellect, which orders truth to work, there are two, by which it is perfected for directing and regulating human operations:

4. Art (techne), which rules transitive operations by which something is made in exterior matter, such as building, cutting, etc.

5. Prudence (phronesis), which rules operations remaining in the agent himself, such as willing, loving, becoming angry, etc.

Art is defined as right reason of things to be made, which directs the works themselves or effects to be made according to certain rules; prudence, as right reason of things to be done, which directs human acts.

589. In what sense they are virtues. - The first four are virtues in a qualified sense, because they do not incline to acting honorably: for they give only aptitude for operating well, not good use, because this pertains to the appetite, whence the work of art can be morally worst; - on the contrary, prudence, by which human reason is well disposed for ordering human acts in the appetite as means to an honorable end, is a virtue simply so called.

This virtue is most necessary to man. For in order to live honorably, it is not enough that man will some good end (what he is to do), but it is also especially required that he order suitable means to the end (how he is to act). Toward the due end man is disposed in the appetite through moral virtue; but for the means to be ordered suitably to the end, reason, moved by the will, also must be well disposed, which is done through prudence: for to deliberate, judge, and command concerning means precisely to be chosen are acts of reason; but prudence disposes us well to doing these rightly.

590. Corollary. - Hence, although prudence according to essence and by reason of the subject is an intellectual virtue, by reason of the matter, which is an honorable human act, it agrees with the moral virtues. Whence it is numbered among them when they are opposed to the theological virtues.