Article I. On the Causes of Sins in General

382. Preliminary note. Since sin, that "mystery of iniquity," is the greatest among all evils, it is of great interest to know its causes; for if its causes are clearly known, it will also be easier to avoid sin itself. For this reason St. Thomas treats at greatest length, that is, through ten questions in 45 articles, of the causes of sins.¹ But we, studying brevity, cannot treat specially except of the efficient cause and of the exciting causes. For four causes are customarily distinguished: material, formal, efficient, final.

The material cause² of sin is that in which sin resides, namely first of all the will, and then also the sensitive appetite and the intellective faculty, but not the external members. For where there is virtue, there sin can be. But in those powers, as being in some way free, virtue can be, but not in the external members, since these are necessarily moved. Thus, for example, the virtue of temperance is in the concupiscible appetite, but fortitude is in the irascible appetite.

The formal cause of sin is its essential constitutive element, namely aversion from God, the ultimate end, if there is question of mortal sin, and disordered conversion to created good.

The principal efficient cause of sin is its author, namely the perverse will, as will soon be proved more broadly. Nevertheless several other secondary efficient causes exist, as will be said below.

The final cause of sin is its intended end. There are indeed diverse particular ends of diverse sins, but the common end of all sins is earthly happiness disorderedly sought.

Leaving aside the material, formal, and final causes, we now treat only of the efficient cause of sin, which indeed is twofold: one interior, namely the faculties of man: intellect, will, imagination, sensitive appetite;³ the other exterior, namely the devil, the world, external goods.⁴

¹ S. theol. 1, 2, q. 75-84.

² It is often also called the subject of sin. S. theol. 1, 2, q. 74.

³ S. theol. 1, 2, q. 75, a. 2.

⁴ Ib. a. 3.

383. Principle. The adequate efficient cause of sin is neither God nor the devil, but only the perverse will. So all Catholic authors. It is proved by parts:

a) God is not the cause of sin, as Simon Magus, several Gnostics, the Manichaeans, the Albigensians, Calvin, Zwingli, Beza, and others wished, teaching that God from eternity positively defined and willed all sins which happen in the world.^4a But this is manifestly false and impious. For in Scripture it is said: "Thou art not a God willing iniquity";⁵ and: "Let no one, when he is tempted, say that he is tempted by God; for God is not a tempter of evils, and he himself tempts no one."⁶ Hence the Council of Trent deservedly defined:⁷ "If anyone says that it is not in the power of man to make his ways evil, but that God works evil works just as he works good works, not only permissively, but also properly and by himself, so that the betrayal of Judas is his own work no less than the calling of Paul, A. S." - This dogmatic truth can easily be proved also from natural reason. For God made every creature for himself and draws all men to himself. Moreover mortal sin is essentially aversion from God, as was said above. Therefore if God willed or caused sin, he would will contraries, namely to convert men to himself and to turn them away from himself.

For greater clarity, however, two things must be distinguished in sin, namely the act itself materially considered and the malice or deformity of the act.

The act materially taken is some being and good, and therefore is caused by God, since there cannot be any being which is not caused by God. Hence, for example, the physical act of adultery is caused by God.

But the malice or deformity of the act, in which precisely the essence of sin consists, is in no way caused by God. For it is privation and defect. To declare this matter more, St. Thomas often uses the example of a lame leg. For just as the soul moves the lame leg and causes the motion, but not the lameness itself, so God moves man to the act and causes the action, but does not cause the defect and disorder of the act. Likewise, as lameness comes from a sick leg, so the disorder or sinfulness of the act comes from the perverse will of man.⁸ Hence God in no way wills or causes the evil of fault which is found in any sinful act, although he causes the physical act of sin. But God permits all sins, because unless God permits, nothing would happen. In this sense St. Augustine said:⁹ "That which happens even against his [God's] will does not happen apart from his will, because it would not happen if he did not permit it; and certainly he does not permit unwillingly, but willingly."

^4a Cf. Billuart, De pecc. diss. 5, a. 9.

⁵ Ps. 5, 5.

⁶ Iac. 1, 13.

⁷ Sess. 6, can. 6 de iustif. (Denz. n. 816).

⁸ Cf. S. theol. 1, 2, q. 79, a. 2.

⁹ Enchir. c. 100 (Migne, Patr. lat. 40, 279).

384. b) The devil is not the direct and sufficient cause of sin. The reason is that the devil cannot cause sin in us except either by directly moving the will to sinning, or by proposing some evil object and efficaciously persuading that this object is to be sought. But he can do neither. Therefore...

alpha) The devil certainly cannot sufficiently move the human will, for the human will is essentially free, and therefore its essence would be destroyed if some extrinsic agent could force it to some act. Wherefore St. Thomas in many places forcefully teaches that an evil angel cannot directly and sufficiently move the human will.¹⁰ Indeed man can and must resist the devil, and therefore St. Peter admonishes: "Your adversary the devil, as a roaring lion, goes about seeking whom he may devour; resist him, strong in faith";¹¹ and St. James similarly says: "Be subject therefore to God; but resist the devil, and he will flee from you."¹²

beta) Next, the devil cannot efficaciously move the will by proposing an object, because the will is moved necessarily by no object except by the ultimate end alone. Indeed the devil can stain the human imagination with unlawful images of every kind; indeed he can totally disturb the use of reason, and also cause most vehement disordered motions in the sensitive appetite; but since the human will always remains free mistress of its acts, hence the devil cannot sufficiently and certainly cause formal sin. St. Thomas¹³ briefly states this truth in this way: "The devil by his own power, unless he is restrained by God, can induce someone by necessity to doing some act which of its own genus is a sin, but he cannot induce the necessity of sinning."

There have been those who taught that all sins of men are at least from the suggestion of the devil. But St. Thomas¹⁴ expressly denies this, teaching: "Occasionally indeed and indirectly the devil is the cause of all our sins, insofar as he induced the first man to sin, from whose sin human nature has been so vitiated that we all are inclined to sin.... But directly he is not the cause of all human sins, such that he persuades individual sins. Origen proves this from the fact that, even if the devil did not exist, men would have appetite for foods and sexual things and the like; and this could be disordered unless it were ordered by reason, which is subject to free will." - These things must be kept before the eyes; for they serve to foster our humility. For we must not say, as the first parents did in paradise: The devil seduced us to sin; but it is necessary humbly to confess: I have sinned exceedingly through my fault, through my most grievous fault. Therefore only the perverse will, led by disordered love of self, is the adequate cause of sin. Indeed besides the devil, also perverse men, worldly allurements, and one's own disordered passions can instigate to sin, but it belongs to the will alone to consent to sin, and without that consent no sin can ever be present.

¹⁰ Cf. S. theol. 1, 2, q. 9, a. 6; q. 80, a. 1 et 3; De malo q. 3, a. 4.

¹¹ 1 Petr. 5, 8.

¹² Iac. 4, 7.

¹³ S. theol. 1, 2, q. 80, a. 3.

¹⁴ L. c. a. 4.