Commentaria in Summam contra Gentiles, Liber III

After St. Thomas has shown that man needs divine grace to persevere in the good, he wishes further to show that he also needs it to rise from sin ¹. Concerning this, however, he does two things: first, he shows the proposed thesis; second, he resolves a certain doubt, ch. 159.

Concerning the first, he does three things: first, he shows that man, if he falls into sin (namely, while the state of this life lasts), can be restored through the help of grace; second, that this cannot happen without grace, in the following chapter; third, how man is freed from sin, ch. 158.

I. As to the first, he argues first thus. Man perseveres in the good by the help of divine grace. Therefore, if he has fallen through sin, he can be restored by the help of the same grace.

— The consequence is proved. Because it belongs to the same power to continue someone's health, and to restore it when interrupted: as is clear regarding natural power with respect to health.

Secondly. God does not require merit in the will to confer grace, since it is given without merits: just as He does not require a natural disposition in a bodily subject. Therefore He can confer the grace through which sins are removed upon someone even after he has fallen from grace through sin. — The consequence is proved. Because an agent that does not require a disposition in a subject can imprint its effect upon a subject however it is disposed.

2. Concerning that proposition, God does not require a natural disposition in a bodily subject, it must be noted, from the doctrine of St. Thomas, I-II, q. 112 ², that this is understood of a disposition preceding divine action and which He Himself does not cause: not, however, of a disposition accompanying the form and caused by God Himself together with the form. For since form and matter must be proportioned—because not every form is fitting for every matter: for the intellective soul cannot be received in the matter of a stone as its form—it is necessary, in order for matter to receive form, that it be disposed by dispositions whereby it is proportioned to that form. But there is a difference between God and a natural agent: because a natural agent, before it induces the form, pre-requires in the matter certain dispositions toward the form; God, however, does not pre-require dispositions in the matter, but can cause the form and the dispositions at the same time, and thus can simultaneously both inform the matter and dispose it for the form.

Nor does it stand in the way that He does not infuse a rational soul unless the matter has been disposed by a natural agent:—because this is not due to necessity, as though He were unable to act otherwise, since He informed the first man with an intellective soul without any disposition from a natural agent, and also in the resurrection of man the matter is not predisposed by a natural agent: but rather that He might communicate some causality to man regarding the production of another man.

II. Thirdly. The help of grace is given to man, not through generation, but after he already exists. Therefore etc. — The consequence is proved. Because man cannot recover, once lost, only those things that come to him through generation: for the reason that man cannot be generated a second time.

Fourthly. Habits acquired through acts, if they are lost, can be reacquired through similar acts. Therefore much more can grace be restored by divine operation. — The consequence is proved. Because grace is a certain habitual disposition in the soul.

Fifthly. In man, after he has fallen into sin, as long as the state of this life lasts, an aptitude to be moved toward the good remains: a sign of which is that there remains in him a desire for the good, and sorrow over evil. Therefore etc. — The consequence is proved. Because what is naturally apt to be moved toward some end can reach that end: otherwise it would be moved in vain. But in the works of God nothing is in vain: just as neither in the works of nature.

III. Sixthly. In the human soul, even after sin, there remains a potency for the good: because natural potencies, through which the soul is ordered to its good, are not removed by sin. Therefore etc. — The consequence is proved. Because, since no passive potency is found in the nature of things that cannot be reduced to act by some natural active power, much less is there any potency in the human soul that is not reducible to act by the divine active power.

2. For the clarity of this argument, it should be considered that, since there is a twofold potency of the soul for the good, namely for the natural good and for the supernatural good; here St. Thomas speaks of the potency of the soul for the supernatural good: because he speaks of the potency for the reception of grace and for merit, which is to be reduced to act by the divine active power. And because the potency for supernatural things is properly an obediential potency, not a natural one: therefore, when it is said that the soul is in potency to the good, and is reducible to act by divine power, this is to be understood of obediential potency.

Nor does it stand in the way that St. Thomas proves that a potency for the good remains in the soul after sin from the fact that natural potencies, by which the soul is ordered to the good, are not removed by sin:—because we can speak of a potency of this kind in two ways. In one way, as to the very quality of the soul that is called its potency, according to which it is capable of supernatural good, for example, of the intellect and will itself; in another way, of the order of this quality to the good. If we take it in the first way, then such a potency is natural, because it is a quality inseparably accompanying the nature of the soul: hence it can be called natural in order to the soul. If, however, in the second way, then it is not natural, but obediential in order to the good. But because that relation according to which the intellective soul is said to be in obediential potency to the good is founded upon the potency of the soul which is its natural quality; therefore St. Thomas shows that an obediential potency of this kind remains after sin, because sin does not take away the natural potencies themselves of the soul, namely the natural qualities; not, however, because the potency as to its order to the supernatural good is natural.

It is confirmed, first, by the authority of Isaiah 1, and Proverbs 10.

It is confirmed, secondly, because we continually ask for this, saying: Forgive us our debts.

Through this is excluded the error of the Novatians, who say that man cannot obtain pardon for sins committed after baptism.