I answer that, the devil is the occasional and indirect cause of all our sins, in so far as he induced the first man to sin, by reason of whose sin human nature is so infected, that we are all prone to sin:  even as the burning of wood might be imputed to the man who dried the wood so as to make it easily inflammable.  He is not, however, the direct cause of all the sins of men, as though each were the result of his suggestion.  Origen proves this (Peri Archon iii, 2) from the fact that even if the devil were no more, men would still have the desire for food, sexual pleasures and the like; which desire might be inordinate, unless it were subordinate to reason, a matter that is subject to the free-will.

Reply Obj. 1:  The crowd of demons are the cause of all our evils, as regards their original cause, as stated.

Reply Obj. 2:  A man becomes another’s slave not only by being overcome by him, but also by subjecting himself to him spontaneously:  it is thus that one who sins of his own accord, becomes the slave of the devil.

Reply Obj. 3:  The devil’s sin was irremediable, not only because he sinned without another’s suggestion; but also because he was not already prone to sin, on account of any previous sin; which can be said of no sin of man. ________________________

QUESTION 81

OF THE CAUSE OF SIN, ON THE PART OF MAN
(In Five Articles)

We must now consider the cause of sin, on the part of man.  Now, while man, like the devil, is the cause of another’s sin, by outward suggestion, he has a certain special manner of causing sin, by way of origin.  Wherefore we must speak about original sin, the consideration of which will be three-fold:  (1) Of its transmission; (2) of its essence; (3) of its subject.

Under the first head there are five points of inquiry: 

(1) Whether man’s first sin is transmitted, by way of origin to his descendants?

(2) Whether all the other sins of our first parent, or of any other parents, are transmitted to their descendants, by way of origin?

(3) Whether original sin is contracted by all those who are begotten of Adam by way of seminal generation?

(4) Whether it would be contracted by anyone formed miraculously from some part of the human body?

(5) Whether original sin would have been contracted if the woman, and not the man, had sinned? ________________________

FIRST ARTICLE [I-II, Q. 81, Art. 1]

Whether the First Sin of Our First Parent Is Contracted by His
Descendants, by Way of Origin?

Objection 1:  It would seem that the first sin of our first parent is not contracted by others, by way of origin.  For it is written (Ezech. 18:20):  “The son shall not bear the iniquity of the father.”  But he would bear the iniquity if he contracted it from him.  Therefore no one contracts any sin from one of his parents by way of origin.