Summa Theologiae Moralis, vol. I: De Principiis

S. Th. I-II, q. 61; De Virt. q. 5, a. 1; q. 1, a. 12, ad 26.

597. Principle I. Certain virtues are called cardinal, as it were principal on which others are founded: thus metaphorically from the hinge on which the door turns; whence those are so called on which as on hinges the moral life turns and on which the whole right human life is founded¹. Since they are principal in human life, they are not merely intellectual virtues and in a qualified sense, but they are simply so called and moral, which alone contain the rectitude of the appetite and which excel the intellectual ones with respect to good.

That there are four cardinal virtues is proved:

1. By reason of the object: The good of reason which is the object of virtue, can be considered either in the very act of reason which considers it, or in the various matters in which it must be produced, namely in operations and in passions. Some passions however impel to something contrary to reason, others withdraw from what reason dictates. Thus therefore there will be one principal virtue which makes good in reason itself: prudence; and one which makes good in operations: justice; and one which moderates and represses the passions impelling to the contrary of reason: temperance; and one which strengthens us against the passions withdrawing from the order of reason: fortitude.

2. By reason of the subject: There are four faculties of the soul in which virtues reside and in each a principal virtue ought to be present: in reason therefore is prudence; in will justice; in concupiscible temperance; in irascible is fortitude, 598. The cardinal virtues are not always understood by all in the same sense. — For some take them in a generic sense, as general modes which are found in several, indeed in all virtues²; either

a) as four genera or collections of virtues, under which all others are contained as species, so that whatever virtue makes good in the consideration of reason is called prudence (e.g. eubulia), and whatever virtue makes rectitude in operations is called justice (e.g. religion, piety, gratitude), and whatever virtue restrains and represses passions is called temperance (e.g. meekness, humility), and whatever virtue makes firmness of soul against certain passions is called fortitude (e.g. magnificence, magnanimity); — or even

b) as general conditions required for every virtue, inasmuch as every virtue must be prudent, and just, and strong, and moderate.

But, although these are true, nevertheless they do not describe the proper nature of the cardinal virtues in the strict sense.

599. Principle II. The cardinal virtues are to be taken in a specific sense and are special virtues, which have a determined matter and are distinguished from all others. For:

a) In each genus of virtues (of which was said above) there is something greatest, principal, and more difficult, about which there is a special virtue: thus in the act by which reason considers, the chief and more difficult is to command well rather than to take counsel and judge well; in operations toward another, the principal is the rectitude of strict equality in which rectitude most shines forth, namely in commutations and distributions; likewise it is more difficult to restrain the more vehement delights, namely the delights of touch, and to strengthen man against the greatest dangers, namely the dangers of death. Whence there are four principal virtues, inasmuch as they are concerned with the principal matter: prudence strictly so called which is preceptive of good, justice properly so called which is about due actions among equals, temperance properly so called which represses the concupiscences of the delights of touch, and fortitude strictly so called which strengthens against the dangers of death.

b) Since however he who is well disposed to doing the principal, and more difficult, by that very fact has a certain inchoate disposition and facility for what is less difficult, according to the adage: He who can do more, can do less (just as he who can restrain the concupiscences of the flesh, which is more difficult, by that very fact is more able to restrain other passions, which is easier; and he who is just can already become liberal, grateful, pious, which otherwise he could not), hence he who has these four special virtues has, at least according to a beginning, all the other moral ones, and therefore they are the foundation of all the others, and are rightly called cardinal³.

The others are called annexed which are concerned with secondary acts or matters, or potential parts, as it were not having the whole power of the principal virtue.