Objection 1: It seems that the priest can bind and loose according to his own judgment. For Jerome says: the canons do not fix the length of time for doing penance so precisely as to say how each sin is to be amended, but leave the decision of this matter to the judgment of a discreet priest. (Cf. Can. 86, Mensuram, de Poenit. Dist. i) Therefore, it seems that he can bind and loose according to his own judgment.

Obj. 2: Further, the Lord commended the unjust steward for as much as he had done wisely (Luke 16:5), because he had allowed a liberal discount to his master’s debtors. But God is more inclined to mercy than any temporal lord. Therefore, it seems that the more punishment the priest remits, the more he is to be commended.

Obj. 3: Further, Christ’s every action is our instruction. Now on some sinners he imposed no punishment, but only amendment of life, as in the case of the adulterous woman (John 8:11). Therefore, it seems that the priest also, who is the vicar of Christ, can, according to his own judgment, remit the punishment either wholly or in part.

On the contrary, Gregory VII says: we declare it a mock penance if it is not imposed according to the authority of the holy fathers in proportion to the sin (Cf. Acts 5.5). Therefore, it seems that it does not altogether depend on the priest’s judgment.

Further, The act of the keys requires discretion. Now, if the priest could remit and impose as much as he liked of a penance, he would have no need of discretion, because there would be no room for indiscretion. Therefore, it does not altogether depend on the priest’s judgment.

I answer that, In using the keys, the priest acts as the instrument and minister of God. Now, no instrument can have an efficacious act except insofar as it is moved by the principal agent. Wherefore Dionysius says that priests should use their hierarchical powers according as they are moved by God (On the Ecclesiastical Hierarchies). A sign of this is that before the power of the keys was conferred on Peter mention is made of the revelation of divinity made to him (Matt 16:17); and before the power of forgiveness, the gift of the Holy Spirit is given to the apostles (John 20:22), for by it they act as sons of God (Rom 8:14). Consequently, if anyone were to presume to use his power against that divine motion, he would not realize the effect, as Dionysius states (On the Ecclesiastical Hierarchies). And besides, he would be turned away from the divine order, and consequently would be guilty of a sin.

Moreover, since satisfactory punishments are medicinal, just as the medicines prescribed by the medical art are not suitable to all but have to be changed according to the judgment of a medical man, who follows not his own will but his medical science, so the satisfactory punishments appointed by the canons are not suitable to all, but have to be varied according to the judgment of the priest guided by the divine instinct. Therefore, just as sometimes the physician prudently refrains from giving a medicine sufficiently efficacious to heal the disease, lest a greater danger should arise on account of the weakness of nature, so the priest, moved by divine instinct, sometimes refrains from enjoining the entire punishment due to one sin, lest by the severity of the punishment the sick man come to despair and turn away altogether from repentance.

Reply Obj. 1: This judgment should be guided entirely by the divine instinct.

Reply Obj. 2: The steward is commended also for having done wisely. Therefore, in the remission of the due punishment, there is need for discretion.

Reply Obj. 3: Christ had the power of excellence in the sacraments, so that, by his own authority, he could remit the punishment wholly or in part, just as he chose. Therefore, there is no comparison between him and those who act merely as ministers.