Accordingly, the first-mentioned good of nature is neither destroyed nor diminished by sin.  The third good of nature was entirely destroyed through the sin of our first parent.  But the second good of nature, viz. the natural inclination to virtue, is diminished by sin.  Because human acts produce an inclination to like acts, as stated above (Q. 50, A. 1).  Now from the very fact that thing becomes inclined to one of two contraries, its inclination to the other contrary must needs be diminished.  Wherefore as sin is opposed to virtue, from the very fact that a man sins, there results a diminution of that good of nature, which is the inclination to virtue.

Reply Obj. 1:  Dionysius is speaking of the first-mentioned good of nature, which consists in “being, living and understanding,” as anyone may see who reads the context.

Reply Obj. 2:  Although nature precedes the voluntary action, it has an inclination to a certain voluntary action.  Wherefore nature is not changed in itself, through a change in the voluntary action:  it is the inclination that is changed in so far as it is directed to its term.

Reply Obj. 3:  A voluntary action proceeds from various powers, active and passive.  The result is that through voluntary actions something is caused or taken away in the man who acts, as we have stated when treating of the production of habits (Q. 51, A. 2).

Reply Obj. 4:  An accident does not act effectively on its subject, but it acts on it formally, in the same sense as when we say that whiteness makes a thing white.  In this way there is nothing to hinder sin from diminishing the good of nature; but only in so far as sin is itself a diminution of the good of nature, through being an inordinateness of action.  But as regards the inordinateness of the agent, we must say that such like inordinateness is caused by the fact that in the acts of the soul, there is an active, and a passive element:  thus the sensible object moves the sensitive appetite, and the sensitive appetite inclines the reason and will, as stated above (Q. 77, AA. 1, 2).  The result of this is the inordinateness, not as though an accident acted on its own subject, but in so far as the object acts on the power, and one power acts on another and puts it out of order. ________________________

SECOND ARTICLE [I-II, Q. 85, Art. 2]

Whether the Entire Good of Human Nature Can Be Destroyed by Sin?

Objection 1:  It would seem that the entire good of human nature can be destroyed by sin.  For the good of human nature is finite, since human nature itself is finite.  Now any finite thing is entirely taken away, if the subtraction be continuous.  Since therefore the good of nature can be continually diminished by sin, it seems that in the end it can be entirely taken away.

Obj. 2:  Further, in a thing of one nature, the whole and the parts are uniform, as is evidently the case with air, water, flesh and all bodies with similar parts.  But the good of nature is wholly uniform.  Since therefore a part thereof can be taken away by sin, it seems that the whole can also be taken away by sin.