Whether a man ought to have contrition for another's sin?

❌ Objection 1 : It would seem that a man ought to have contrition for another's sin. For one should not ask forgiveness for a sin unless one is contrite for it. Now forgiveness is asked for another's sin in Ps. 18:13: "From those of others spare thy servant." Therefore a man ought to be contrite for another's sins.

❌ Objection 2 : Further, man is bound, ought of charity, to love his neighbor as himself. Now, through love of himself, he both grieves for his ills, and desires good things. Therefore, since we are bound to desire the goods of grace for our neighbor, as for ourselves, it seems that we ought to grieve for his sins, even as for our own. But contrition is nothing else than sorrow for sins. Therefore man should be contrite for the sins of others.