Reply Obj. 1: Mode of action follows on the disposition of the agent: for such as a thing is, such is its act. And therefore, since virtue is the principle of some kind of operation, there must needs pre-exist in the operator in respect of virtue some corresponding disposition. Now virtue causes an ordered operation. Therefore virtue itself is an ordered disposition of the soul, in so far as, to wit, the powers of the soul are in some way ordered to one another, and to that which is outside. Hence virtue, inasmuch as it is a suitable disposition of the soul, is like health and beauty, which are suitable dispositions of the body. But this does not hinder virtue from being a principle of operation.
Reply Obj. 2: Virtue which is referred to being is not proper to man; but only that virtue which is referred to works of reason, which are proper to man.
Reply Obj. 3: As God's substance is His act, the highest likeness of man to God is in respect of some operation. Wherefore, as we have said above (Q. 3, A. 2), happiness or bliss by which man is made most perfectly conformed to God, and which is the end of human life, consists in an operation. ________________________
THIRD ARTICLE [I-II, Q. 55, Art. 3]
Whether Human Virtue Is a Good Habit?
Objection 1: It would seem that it is not essential to virtue that it should be a good habit. For sin is always taken in a bad sense. But there is a virtue even of sin; according to 1 Cor. 15:56: "The virtue [Douay: 'strength'] of sin is the Law." Therefore virtue is not always a good habit.
Obj. 2: Further, Virtue corresponds to power. But power is not only referred to good, but also to evil: according to Isa. 5: "Woe to you that are mighty to drink wine, and stout men at drunkenness." Therefore virtue also is referred to good and evil.
Obj. 3: Further, according to the Apostle (2 Cor. 12:9): "Virtue [Douay: 'power'] is made perfect in infirmity." But infirmity is an evil. Therefore virtue is referred not only to good, but also to evil.
On the contrary, Augustine says (De Moribus Eccl. vi): "No one can doubt that virtue makes the soul exceeding good": and the Philosopher says (Ethic. ii, 6): "Virtue is that which makes its possessor good, and his work good likewise."
I answer that, As we have said above (A. 1), virtue implies a perfection of power: wherefore the virtue of a thing is fixed by the limit of its power (De Coelo i). Now the limit of any power must needs be good: for all evil implies defect; wherefore Dionysius says (Div. Hom. ii) that every evil is a weakness. And for this reason the virtue of a thing must be regarded in reference to good. Therefore human virtue which is an operative habit, is a good habit, productive of good works.