We proceed to the eighth article thus:

1. It seems that a man can avoid sin without grace. Augustine says that "no man sins in respect of what he cannot avoid" (De Duab. Animabus, 10, 11; 3 De Lib. Arb.18). Hence it appears sthat if a man cannot avoid sin while he lives in mortal sin, he does not sin while he sins. But this is impossible.

2. Again, one is chastised in order that one may not sin. But if a man who lived in mortal sin were unable to avoid sin, it seems that it would be useless to chastise him. But this is impossible.

3. Again, it is said in Ecclesiasticus 15:17: "Before man are life and death, good and evil; whatsoever he shall choose shall be given him." But when a man sins, he does not cease to be a man. It is therefore still within his power to choose either good or evil. Hence one who lacks grace can avoid sin.

On the other hand: Augustine says (De Perf. Just.21): "Whosoever denies that we ought to pray lead us not into temptation' (and he denies this who argues that a man does not need the help of God's grace in order not to sin) should assuredly be removed from every ear and anathematized by every mouth."

I answer: we may speak of man in two ways; either as in the state of pure nature, or as in the state of corrupt nature. In the state of pure nature, man could avoid both mortal and venial sin, without grace. For to sin is nothing other than to fall short of what befits one's nature, and a man in the state of pure nature could avoid this. Yet he could not avoid it without the help of God preserving him in good, without which help his nature itself would have ceased to exist. But in the state of corrupt nature a man needs grace to heal his nature continually, if he is to avoid sin entirely. In our present life this healing is accomplished first in the mind, the appetite of the flesh being not yet wholly cured. Hence the apostle, speaking as one who is restored, says in Rom.7:25: "with the mind I myself serve the law of God, but with the flesh the law of sin." A man in this state can avoid all mortal sin, which has to do with his reason, as we said in Q.74, Art.5. But he cannot avoid all venial sin, owing to the corrupt sensuality of his lower appetite. Reason can indeed suppress the urges of the lower appetite severally, wherefore they are sinful and voluntary. But it cannot suppress all of them. For while a man endeavours to suppress one of them, another may arise. Moreover, as we said in Q.74, Art.10, reason cannot always be vigilant enough to suppress such urges.

But before his reason is restored through justifying grace, a man can likewise avoid severally, for some time, the mortal sins which have to do with his reason, since he is not bound by necessity actually to sin at all times. But he cannot continue without mortal sin for long. As Gregory says, "a sin which is not instantly blotted out by repentance drags us down to another by its weight" {Hom. in Ezech.11:25 Moral.9). This is because reason ought to be subject to God, and ought to find in God the end which it desires, just as the lower appetite ought to be subject to reason. Every human action, indeed, ought to be regulated by this end, just as the urges of the lower appetite ought to be regulated by the judgment of reason. There are therefore bound to be many untoward actions of reason itself when reason is not entirely subject to God, just as there are bound to be uncontrolled movements of the sensitive appetite when the lower appetite is imperfectly subject to reason. When a man's heart is not so firmly fixed on God that he is unwilling to be separated from him for the sake of any good, or to avoid any evil, he forsakes God, and breaks his commandments in order to gain or to avoid many things. He thus sins mortally, especially since "he acts according to his preconceived end and previous habit whenever he is caught off his guard," as the philosopher says in 3 Ethics 8. Premeditation may perhaps enable him to do something better than his preconceived end requires, and better than that to which his habit inclines. But he cannot be always premeditating, and will not perchance continue for long before suiting his action to a will which is not controlled by God, unless he is quickly restored to right order by grace.

On the first point: as we have said, a man can avoid sinful actions taken singly, but he cannot avoid all of them, unless through grace. Yet his sin is not to be excused on the ground that he cannot avoid it without grace, because it is due to his own fault that he does not prepare himself for grace.

On the second point: as Augustine says (De Corrept. et Grat.6): "chastisement is useful in order that the desire for regeneration may arise out of the pain of it. While the noise of chastisement resounds without, God may work within by an unseen inspiration, that one should so desire, if one be a son of promise." Chastisement is necessary because a man must desist from sin of his own will. But it is not enough without the help of God. Wherefore it is said in Eccl.7:13: "Consider the work of God: for who can make that straight which he hath made crooked?" [33]

On the third point: as Augustine says (or another, in Hypognosticon 3, cap.1,2), this saying must be understood as referring to man in the state of pure nature, not yet the slave of sin, able both to sin and not to sin. Whatever a man then desires is given him. It is nevertheless by the help of grace that he desires what is good.

[33] Migne: "for no one can correct one whom he hath despised."