Of the Causes of Sin, in General

Of the Causes of Sin, in General — St. Thomas Aquinas asks: Whether sin has a cause?; Whether sin has an internal cause?; Whether sin has an external cause?; Whether one sin is a cause of another?.

We must now consider the causes of sin: (1) in general; (2) in particular. Under the first head there are four points of inquiry:

Article 1: Whether sin has a cause?

Whatever is done has a cause, for, according to Job 5:6, "nothing upon earth is done without a cause." But sin is something done; since it a "word, deed, or desire contrary to the law of God." Therefore sin has a cause.

A sin is an inordinate act. Accordingly, so far as it is an act, it can have a direct cause, even as any other act; but, so far as it is inordinate, it has a cause, in the same way as a negation or privation can have a cause. Now two causes may be assigned to a negation: in the first place, absence of the cause of affirmation; i.e. the negation of the cause itself, is the cause of the negation in itself; since the result of the removing the cause is the removal of the effect: thus the absence of the sun is the cause of darkness. In the second place, the cause of an affirmation, of which a negation is a sequel, is the accidental cause of the resulting negation: thus fire by causing heat in virtue of its principal tendency, consequently causes a privation of cold. The first of these suffices to cause a simple negation. But, since the inordinateness of sin and of every evil is not a simple negation, but the privation of that which something ought naturally to have, such an inordinateness must needs have an accidental efficient cause. For that which naturally is and ought to be in a thing, is never lacking except on account of some impeding cause. And accordingly we are wont to say that evil, which consists in a certain privation, has a deficient cause, or an accidental efficient cause. Now every accidental cause is reducible to the direct cause. Since then sin, on the part of its inordinateness, has an accidental efficient cause, and on the part of the act, a direct efficient cause, it follows that the inordinateness of sin is a result of the cause of the act. Accordingly then, the will lacking the direction of the rule of reason and of the Divine law, and intent on some mutable good, causes the act of sin directly, and the inordinateness of the act, indirectly, and beside the intention: for the lack of order in the act results from the lack of direction in the will.

Article 2: Whether sin has an internal cause?

Augustine says (De Duabus Anim. x, 10,11; Retract. i, 9) that "the will is the cause of sin."

As stated above (), the direct cause of sin must be considered on the part of the act. Now we may distinguish a twofold internal cause of human acts, one remote, the other proximate. The proximate internal cause of the human act is the reason and will, in respect of which man has a free-will; while the remote cause is the apprehension of the sensitive part, and also the sensitive appetite. For just as it is due to the judgment of reason, that the will is moved to something in accord with reason, so it is due to an apprehension of the senses that the sensitive appetite is inclined to something; which inclination sometimes influences the will and reason, as we shall explain further on (). Accordingly a double interior cause of sin may be assigned; one proximate, on the part of the reason and will; and the other remote, on the part of the imagination or sensitive appetite.

But since we have said above () that the cause of sin is some apparent good as motive, yet lacking the due motive, viz. the rule of reason or the Divine law, this motive which is an apparent good, appertains to the apprehension of the senses and to the appetite; while the lack of the due rule appertains to the reason, whose nature it is to consider this rule; and the completeness of the voluntary sinful act appertains to the will, so that the act of the will, given the conditions we have just mentioned, is already a sin.

Article 3: Whether sin has an external cause?

It is written (Num. 21:16): "Are not these they, that deceived the children of Israel by the counsel of Balaam, and made you transgress against the Lord by the sin of Phogor?" Therefore something external can be a cause of sin.

As stated above (), the internal cause of sin is both the will, as completing the sinful act, and the reason, as lacking the due rule, and the appetite, as inclining to sin. Accordingly something external might be a cause of sin in three ways, either by moving the will itself immediately, or by moving the reason, or by moving the sensitive appetite. Now, as stated above (; ), none can move the will inwardly save God alone, who cannot be a cause of sin, as we shall prove further on (). Hence it follows that nothing external can be a cause of sin, except by moving the reason, as a man or devil by enticing to sin; or by moving the sensitive appetite, as certain external sensibles move it. Yet neither does external enticement move the reason, of necessity, in matters of action, nor do things proposed externally, of necessity move the sensitive appetite, except perhaps it be disposed thereto in a certain way; and even the sensitive appetite does not, of necessity, move the reason and will. Therefore something external can be a cause moving to sin, but not so as to be a sufficient cause thereof: and the will alone is the sufficient completive cause of sin being accomplished.

Article 4: Whether one sin is a cause of another?

Gregory says on Ezechiel (Hom. xi): "A sin is not quickly blotted out by repentance, is both a sin and a cause of sin."

Forasmuch as a sin has a cause on the part of the act of sin, it is possible for one sin to be the cause of another, in the same way as one human act is the cause of another. Hence it happens that one sin may be the cause of another in respect of the four kinds of causes. First, after the manner of an efficient or moving cause, both directly and indirectly. Indirectly, as that which removes an impediment is called an indirect cause of movement: for when man, by one sinful act, loses grace, or charity, or shame, or anything else that withdraws him from sin, he thereby falls into another sin, so that the first sin is the accidental cause of the second. Directly, as when, by one sinful act, man is disposed to commit more readily another like act: because acts cause dispositions and habits inclining to like acts. Secondly, after the manner of a material cause, one sin is the cause of another, by preparing its matter: thus covetousness prepares the matter for strife, which is often about the wealth a man has amassed together. Thirdly, after the manner of a final cause, one sin causes another, in so far as a man commits one sin for the sake of another which is his end; as when a man is guilty of simony for the end of ambition, or fornication for the purpose of theft. And since the end gives the form to moral matters, as stated above (; ), it follows that one sin is also the formal cause of another: because in the act of fornication committed for the purpose of theft, the former is material while the latter is formal.