Reply Obj. 4:  The corruption of original sin is nowise caused by God, but by the sin alone of our first parent through carnal generation.  And so, since creation implies a relation in the soul to God alone, it cannot be said that the soul is tainted through being created.  On the other hand, infusion implies relation both to God infusing and to the flesh into which the soul is infused.  And so, with regard to God infusing, it cannot be said that the soul is stained through being infused; but only with regard to the body into which it is infused.

Reply Obj. 5:  The common good takes precedence of private good.  Wherefore God, according to His wisdom, does not overlook the general order of things (which is that such a soul be infused into such a body), lest this soul contract a singular corruption:  all the more that the nature of the soul demands that it should not exist prior to its infusion into the body, as stated in the First Part (Q. 90, A. 4; Q. 118, A. 3).  And it is better for the soul to be thus, according to its nature, than not to be at all, especially since it can avoid damnation, by means of grace. ________________________

SECOND ARTICLE [I-II, Q. 83, Art. 2]

Whether Original Sin Is in the Essence of the Soul Rather Than in the
Powers?

Objection 1:  It would seem that original sin is not in the essence of the soul rather than in the powers.  For the soul is naturally apt to be the subject of sin, in respect of those parts which can be moved by the will.  Now the soul is moved by the will, not as to its essence but only as to the powers.  Therefore original sin is in the soul, not according to its essence, but only according to the powers.

Obj. 2:  Further, original sin is opposed to original justice.  Now original justice was in a power of the soul, because power is the subject of virtue.  Therefore original sin also is in a power of the soul, rather than in its essence.

Obj. 3:  Further, just as original sin is derived from the soul as from the flesh, so is it derived by the powers from the essence.  But original sin is more in the soul than in the flesh.  Therefore it is more in the powers than in the essence of the soul.

Obj. 4:  Further, original sin is said to be concupiscence, as stated (Q. 82, A. 3).  But concupiscence is in the powers of the soul.  Therefore original sin is also.

On the contrary, Original sin is called the sin of nature, as stated above (Q. 81, A. 1).  Now the soul is the form and nature of the body, in respect of its essence and not in respect of its powers, as stated in the First Part (Q. 76, A. 6).  Therefore the soul is the subject of original sin chiefly in respect of its essence.