We proceed to the second article thus:
1. It seems that an infusion of grace is not required for the remission of guilt, which is the justification of the ungodly. For if there is a mean between two contraries, it is possible to be delivered from one of them without being brought to the other. Now there is a mean between the state of guilt and the state of grace, namely the state of innocence, in which one has neither grace nor guilt. One may therefore be forgiven one's guilt without being brought to grace.
2. Again, remission of guilt consists in divine forbearance to impute it, according to Ps.32:2: "Blessed is the man unto whom the Lord imputeth not iniquity." Infusion of grace, on the other hand, denotes something within us, as was maintained in Q.110, Art.1. It follows that an infusion of grace is not required for the remission of guilt.
3. Again, no one can be subject to two contraries at once. Now certain sins are contraries, like prodigality and parsimony. Whoever is subject to the sin of prodigality cannot then be subject to the sin of parsimony at the same time, although he may have bean subject to it previously. Hence he is set free from the sin of parsimony through sinning by the vice of prodigality. Thus a sin is remitted without grace.
On the other hand: it is said in Rom.3:24: "Being justified freely by his grace."
I answer: it is clear from what we said in Q.71, Art.5, that when a man sins, he offends God. Now an offence is not remitted unless the mind of the offended one is pacified towards the offender. Our sin is accordingly said to be remitted when God is pacified towards us. This peace is one with the love with which God loves us. But although the love of God is eternal and unchangeable as a divine action, the effect which it impresses upon us is intermittent, since we sometimes lose it and recover it again. Moreover, the effect of the divine love which we forfeit through sin is grace, and grace makes a man worthy of the eternal life from which mortal sin excludes him. The remission of sin would therefore be meaningless if there were no infusion of grace.
On the first point: to forgive an offender for an offence demands more than is required merely to feel no hatred towards one who does not offend. For it can happen with men that one man neither loves not hates another, and yet will not forgive an offence if the other should offend him, unless through exceptional good will. Now God's good will to man is said to be renewed by a gift of grace. Hence although a man may have been without either grace or guilt before he sins, he cannot be without guilt after he sins, unless he has grace.
On the second point: just as God's love not only consists in a divine act of will, but also implies some effect of grace, as we said in Q. no, Art. i, so also the divine forbearance to impute sin implies some effect in him to whom God does not impute it. For God's forbearance to impute sin is an expression of his love.
On the third point: as Augustine says (1 De Nup. et Concup.26): "If to be sinless were merely to desist from sin, it would be enough if the scriptural warning were this -- 'My son, thou hast sinned. Do it not again.' But this is not enough, wherefore there is added and pray that thy former sins may be forgiven thee.'" Now sins endures as guilt, though it is transient as an action, as we said in Q.87, Art.6. Hence although a man ceases from the action of his former sin when he passes from the sin of one vice to the sin of a contrary vice, he does not cease to bear the guilt of it. Indeed, he bears the guilt of both sins simultaneously. Moreover, sins are not contrary to each other in respect of turning away from God, which is the very reason why sin involves guilt.