Summa Theologiae Moralis, vol. I: De Principiis

S. Th. I-II, q. 58-60; De Virt. q. 1, a. 4, 5, 12.

591. Moral virtue is named from mores i.e. inclination to acting, which properly pertains to the appetite; whence moral virtue is the habit by which the appetite is well disposed to be conformed to reason. In fact it is the habitual conformity to right reason. Since however to choose is the act proper to the human appetite, hence moral virtue is an elective habit according to right reason, and is defined by Aristotle, Eth. VI, c. 6: an elective habit consisting in a mean with respect to us, determined by reason as the wise man will determine¹. It is called

1°) elective habit, because choice is the proper act of moral virtue, and because moral habit is the principle of choice;

2°) consisting in a mean with respect to us: this is the object or term of this action. The moral good which is the object of virtue is a mean between excess and defect, which is to be estimated not in itself, but with respect to the one choosing, so that he chooses what is fitting for him according to right reason, neither more nor less;

3°) determined by reason: this is the cause of goodness. For it is reason which determines the mean between excess and defect, that it be good. And because it happens that reason is not always right but also sometimes erroneous, is added: as the wise man, i.e. prudent, will determine; reason namely through prudence will rightly estimate what is good or evil in the acts of the appetite (q. 58, a. 1 and 59, a. 1).

592. Principle I. Moral virtues are necessary. — For both the rational and sensitive appetite does not obey reason entirely at its nod, but can contradict it, because it is properly operative i.e. has its own movements and actions. Whence for operating well it is required that not only the intellect through prudence, but also the appetite be well disposed, to obey reason, through the habits of moral virtues; otherwise it would be moved as if by force and with sadness (q. 58, a. 2).

593. Principle II. Moral virtue is not one in species but multiple, both by reason of the subject or diverse potency in which it is, and by reason of the object (formal principle), which can be related in diverse ways to reason, to which it can participate more or less, and so it says a diverse relation to the directing reason (q. 59, a. 2 and 4; q. 60, a. 1).

For reason directs both the operations of the will by which man is disposed, even externally, toward another, and the passions of the sensitive appetite, both concupiscible and irascible, that they may consent to reason and so man be well disposed internally, in relation to himself. Whence in three ways: and a) by reason of the matter about which principally², and b) by reason of the subject in which they are (will, concupiscible appetite, irascible appetite), and c) by reason of the formal object (good according to commensuration toward another, or good according to mere commensuration toward the agent whether as delightful, or as arduous) the virtues are specifically distinguished — virtues about operations of the will — virtues about passions of the concupiscible, — and virtues about passions of the irascible (q. 60, a. 2).

594. Principle III. Diverse are the virtues about operations. — All the virtues which are about operations agree in the general notion of what is due to another. But the notion of what is due is not of one notion in all: in one way something is due strictly by pact, in another way not strictly by promise or benefit received; in one way something is due to an equal, in another to a superior, in another to a lesser. Whence according to diverse notions of what is due, there are diverse virtues about operations, e.g. justice, religion, piety, gratitude, truthfulness, etc. (q. 60, a. 3).

595. Principle IV. Diverse also are the virtues about the passions of the concupiscible or irascible, not indeed because the passions are diverse, but when they say a diverse relation to reason.

Hence a) the same virtue is concerned with contrary passions between which it holds the mean, e.g. fortitude between fear and daring (q. 60, a. 4);

b) moreover diverse passions in a certain order to one another and to one [end] can be ordered, and in the same way be repugnant to reason (or agree with it), as happens for the passions of the concupiscible: love, desire, and delight of the same good (and consequently also for hatred, flight, sadness of the opposite evil); whence all these passions pertain not to different virtues but to the same virtue, e.g. temperance (a., 4); c) on the contrary, when passions are ordered to a diverse good of reason, and so say a diverse relation to reason, as happens for the passions of the irascible, which « are not of one order but are ordered to diverse things. For daring and fear are ordered to some great danger; hope and despair to some good that is arduous; anger however to overcoming some contrary which has brought harm. And therefore about these passions there are diverse virtues, namely... fortitude about fears and audacities, magnanimity about hope and despair, meekness about angers » (q. 60, a. 4);

d) a fortiori when they pertain to diverse potencies, because then they are concerned with diverse objects, whence other virtues are concerned with the passions of the concupiscible (good as such), others with the passions of the irascible (good as arduous), e.g. temperance and fortitude, love of honor and magnanimity, liberality and magnificence, temperance and meekness, etc.³ (a. 5).

596. Corollaries. — From what has been said it follows:

1° « That of all human operations the first principle is reason,..., whence just as the appetite (rational or sensitive) is the principle of a human act according to this that it participates reason in some way, so the moral habit has the character of human virtue inasmuch as it is conformed to reason » (q. 58, a. 2).

2° Hence, just as intellectual virtue is rational by essence, so moral virtue is rational by participation, inasmuch as the appetite whether the superior of the will or the inferior of the sensitive life participates reason (q.60, a. 1; q.56, a. 4 and ad 1; a. 6, ad 2; q. 58, a. 2; q. 59, a. 4, ad 2; q. 61, a. 2).

3° Moral virtues can be without the intellectual virtues of wisdom, science, and art; not however without prudence, which is necessary for rightly taking the means to the end and which itself presupposes the intellect of practical principles (q. 58, a. 4).

4° Intellectual virtues can be without moral virtues; not however without these is prudence. For that the work be the work of the virtue of prudence, it must be done for the right end, or for good; the right end the moral virtue procures (a. 5).