Whether confession is an act of virtue?

Objections

Objection 1 : It would seem that confession is not an act of virtue. For every act of virtue belongs to the natural law, since "we are naturally capable of virtue," as the Philosopher says (Ethic. ii, 1). But confession does not belong to the natural law. Therefore it is not an act of virtue.
Objection 2 : Further, an act of virtue is more befitting one who is innocent than one who has sinned. But the confession of a sin, which is the confession of which we are speaking now, cannot be befitting an innocent man. Therefore it is not an act of virtue.
Objection 3 : Further, the grace which is in the sacraments differs somewhat from the grace which is in the virtues and gifts. But confession is part of a sacrament. Therefore it is not an act of virtue.