On the contrary, The Law has a special precept about penance, as stated above (Q. 84, AA. 5, 7).
I answer that, As stated in the Second Part (I-II, Q. 54, A. 1, ad 1, A. 2), habits are specifically distinguished according to the species of their acts, so that whenever an act has a special reason for being praiseworthy, there must needs be a special habit. Now it is evident that there is a special reason for praising the act of penance, because it aims at the destruction of past sin, considered as an offense against God, which does not apply to any other virtue. We must therefore conclude that penance is a special virtue.
Reply Obj. 1: An act springs from charity in two ways: first as being elicited by charity, and a like virtuous act requires no other virtue than charity, e.g. to love the good, to rejoice therein, and to grieve for what is opposed to it. Secondly, an act springs from charity, being, so to speak, commanded by charity; and thus, since charity commands all the virtues, inasmuch as it directs them to its own end, an act springing from charity may belong even to another special virtue. Accordingly, if in the act of the penitent we consider the mere displeasure in the past sin, it belongs to charity immediately, in the same way as joy for past good acts; but the intention to aim at the destruction of past sin requires a special virtue subordinate to charity.
Reply Obj. 2: In point of fact, penance has indeed a general matter, inasmuch as it regards all sins; but it does so under a special aspect, inasmuch as they can be remedied by an act of man in co-operating with God for his justification.
Reply Obj. 3: Every special virtue removes formally the habit of the opposite vice, just as whiteness removes blackness from the same subject: but penance removes every sin effectively, inasmuch as it works for the destruction of sins, according as they are pardonable through the grace of God if man co-operate therewith. Wherefore it does not follow that it is a general virtue. _______________________
THIRD ARTICLE [III, Q. 85, Art. 3]
Whether the Virtue of Penance Is a Species of Justice?
Objection 1: It would seem that the virtue of penance is not a species of justice. For justice is not a theological but a moral virtue, as was shown in the Second Part (II-II, Q. 62, A. 3). But penance seems to be a theological virtue, since God is its object, for it makes satisfaction to God, to Whom, moreover, it reconciles the sinner. Therefore it seems that penance is not a species of justice.
Obj. 2: Further, since justice is a moral virtue it observes the mean. Now penance does not observe the mean, but rather goes to the extreme, according to Jer. 6:26: "Make thee mourning as for an only son, a bitter lamentation." Therefore penance is not a species of justice.
Obj. 3: Further, there are two species of justice, as stated in Ethic. v, 4, viz. "distributive" and "commutative." But penance does not seem to be contained under either of them. Therefore it seems that penance is not a species of justice.