Commentaria in Summam contra Gentiles, Liber III

From the foregoing, someone might fall into the error of thinking that God leads men into sin, since it was said ¹ that God does not convert some, but leaves them in their sins according to their deserts. Therefore, setting this aside, St. Thomas lays down this conclusion, that God does not lead into sin those whom He leaves in their sins ².

I. And he argues first as follows. It is impossible that, by God acting, any should be turned away from the ultimate end, which is God. Therefore etc. — The antecedent is proved: because every agent acts for its own end and one suitable to itself. — But the consequence is proved: because men sin by deviating from God, who is the ultimate end.

Note that this argument proceeds from what is commonly found in all agents. For since everything seeks in a certain way to draw other things to itself, by assimilating them to itself or converting them to its own end, it is fitting that God by His action should convert other things to Himself, and consequently turn nothing away from Himself.

Secondly. Sin is an evil for man, inasmuch as it is contrary to his proper good, which is to live according to reason. Therefore etc. — The consequence is proved: because good is not the cause of evil.

Note that, since God is the first cause and is an agent through intellect, He cannot be an accidental cause of anything, because an accidental cause must be reduced to a per se cause. On this account, taking this as manifest, when St. Thomas speaks of God's causality with respect to sin, he speaks of per se causality. Hence, although the good is an accidental cause of evil, as was shown above ³, he nevertheless lays down this proposition absolutely, Good is not the cause of evil, because it holds true of per se causality.

Thirdly. It is repugnant to human wisdom and goodness that one should cause someone to sin. Therefore etc. — The consequence is proved: because the goodness and wisdom of man is derived from the divine goodness and wisdom.

Fourthly. The proximate agent of human sin is the will. Therefore etc. — The consequence is proved: because every sin arises from some defect of the proximate agent, but not from the influence of the first agent, as is clear in limping.

It is confirmed by the authority of Sirach 15 and James 1.

Moreover, it is no objection to this that God is said to harden or blind some, as in Exodus 10, Isaiah 6 and 63, and Romans 1; for by these words nothing else is meant than that God does not bestow on some the help to avoid sin—His justice so demanding—which He does bestow on certain others. And this help is not only the infusion of grace, but also the exterior protection from occasions of sin, and the natural light of reason, and the other natural goods which God bestows on man.

II. Concerning this last statement a doubt arises. For although from the preceding arguments it has been shown that God is not directly the cause of sin, nevertheless from the solution given to these authorities it seems to follow that He is indirectly the cause of sin. For he who can provide help to avoid sin and does not provide it seems to be indirectly the cause of sin.

He answers that something can be called an indirect cause of sinning in two ways. In one way, so that it is said to cause it solely in the manner of not acting toward the opposite, so that to cause sin is nothing other than not to prohibit it, or not to provide help against sin. And in this way it is not unfitting to say that God is indirectly the cause of sin. — In another way, in the manner of one to whom the sin is to be imputed from the fact that he does not act to avoid it. And in this way God is not indirectly the cause of sin: because, if He does not provide help, He does this as His justice and wisdom demand; for the sinking of a ship is not imputed to one not steering the ship unless he is both able and bound to steer it. On this account St. Thomas said that God is said to harden some when He withholds helps from some according to the desert of their action, as His justice demands: namely, either according as the action of the man by which he sinned deserves, or according as the divine action, which is just, requires. Concerning this, see St. Thomas, I-II, q. 79.

How God is not the cause of sin is found in Capreolus, II Sent., d. 37 ⁴; and it was also shown above, chap. 71.