Objection 1. It would seem that there can be true virtue without charity. For it is proper to virtue to produce a good act. Now those who have not charity, do some good actions, as when they clothe the naked, or feed the hungry and so forth. Therefore true virtue is possible without charity.
Objection 2. Further, charity is not possible without faith, since it comes of "an unfeigned faith," as the Apostle says (1 Timothy 1:5). Now, in unbelievers, there can be true chastity, if they curb their concupiscences, and true justice, if they judge rightly. Therefore true virtue is possible without charity.
Objection 3. Further, science and art are virtues, according to Ethic. vi. But they are to be found in sinners who lack charity. Therefore true virtue can be without charity.
On the contrary, The Apostle says (1 Corinthians 13:3): "If I should distribute all my goods to the poor, and if I should deliver my body to be burned, and have not charity, it profiteth me nothing." And yet true virtue is very profitable, according to Wisdom 8:7: "She teacheth temperance, and prudence, and justice, and fortitude, which are such things as men can have nothing more profitable in life." Therefore no true virtue is possible without charity.
I answer that, Virtue is ordered to the good, as stated above (I-II, 55, 4). Now the good is chiefly an end, for things directed to the end are not said to be good except in relation to the end. Accordingly, just as the end is twofold, the last end, and the proximate end, so also, is good twofold, one, the ultimate and universal good, the other proximate and particular. The ultimate and principal good of man is the enjoyment of God, according to Psalm 72:28: "It is good for me to adhere to God," and to this good man is ordered by charity. Man's secondary and, as it were, particular good may be twofold: one is truly good, because, considered in itself, it can be directed to the principal good, which is the last end; while the other is good apparently and not truly, because it leads us away from the final good. Accordingly it is evident that simply true virtue is that which is directed to man's principal good; thus also the Philosopher says (Phys. vii, text. 17) that "virtue is the disposition of a perfect thing to that which is best": and in this way no true virtue is possible without charity.
If, however, we take virtue as being ordered to some particular end, then we speak of virtue being where there is no charity, in so far as it is directed to some particular good. But if this particular good is not a true, but an apparent good, it is not a true virtue that is ordered to such a good, but a counterfeit virtue. Even so, as Augustine says (Contra Julian. iv, 3), "the prudence of the miser, whereby he devises various roads to gain, is no true virtue; nor the miser's justice, whereby he scorns the property of another through fear of severe punishment; nor the miser's temperance, whereby he curbs his desire for expensive pleasures; nor the miser's fortitude, whereby as Horace, says, 'he braves the sea, he crosses mountains, he goes through fire, in order to avoid poverty'" (Epis. lib, 1; Ep. i, 45). If, on the other hand, this particular good be a true good, for instance the welfare of the state, or the like, it will indeed be a true virtue, imperfect, however, unless it be referred to the final and perfect good. Accordingly no strictly true virtue is possible without charity.
Reply to Objection 1. The act of one lacking charity may be of two kinds; one is in accordance with his lack of charity, as when he does something that is referred to that whereby he lacks charity. Such an act is always evil: thus Augustine says (Contra Julian. iv, 3) that the actions which an unbeliever performs as an unbeliever, are always sinful, even when he clothes the naked, or does any like thing, and directs it to his unbelief as end.
There is, however, another act of one lacking charity, not in accordance with his lack of charity, but in accordance with his possession of some other gift of God, whether faith, or hope, or even his natural good, which is not completely taken away by sin, as stated above (10, 4; I-II, 85, 2). On this way it is possible for an act, without charity, to be generically good, but not perfectly good, because it lacks its due order to the last end.
Reply to Objection 2. Since the end is in practical matters, what the principle is in speculative matters, just as there can be no strictly true science, if a right estimate of the first indemonstrable principle be lacking, so, there can be no strictly true justice, or chastity, without that due ordering to the end, which is effected by charity, however rightly a man may be affected about other matters.
Reply to Objection 3. Science and art of their very nature imply a relation to some particular good, and not to the ultimate good of human life, as do the moral virtues, which make man good simply, as stated above (I-II, 56, 3). Hence the comparison fails.
Source: Summa Theologica (New Advent)