Objection 1: It would seem that privation of mode, species and order is not the effect of sin. For Augustine says (De Natura Boni iii) that "where these three abound, the good is great; where they are less, there is less good; where they are not, there is no good at all." But sin does not destroy the good of nature. Therefore it does not destroy mode, species and order.
Obj. 2: Further, nothing is its own cause. But sin itself is the "privation of mode, species and order," as Augustine states (De Natura Boni iv). Therefore privation of mode, species and order is not the effect of sin.
Obj. 3: Further, different effects result from different sins. Now since mode, species and order are diverse, their corresponding privations must be diverse also, and, consequently, must be the result of different sins. Therefore privation of mode, species and order is not the effect of each sin.
On the contrary, Sin is to the soul what weakness is to the body, according to Ps. 6:3, "Have mercy on me, O Lord, for I am weak." Now weakness deprives the body of mode, species and order.
I answer that, As stated in the First Part, Q. 5, A. 5, mode, species and order are consequent upon every created good, as such, and also upon every being. Because every being and every good as such depends on its form from which it derives its species. Again, any kind of form, whether substantial or accidental, of anything whatever, is according to some measure, wherefore it is stated in Metaph. viii, that "the forms of things are like numbers," so that a form has a certain mode corresponding to its measure. Lastly owing to its form, each thing has a relation of order to something else.
Accordingly there are different grades of mode, species and order, corresponding to the different degrees of good. For there is a good belonging to the very substance of nature, which good has its mode, species and order, and is neither destroyed nor diminished by sin. There is again the good of the natural inclination, which also has its mode, species and order; and this is diminished by sin, as stated above (AA. 1, 2), but is not entirely destroyed. Again, there is the good of virtue and grace: this too has its mode, species and order, and is entirely taken away by sin. Lastly, there is a good consisting in the ordinate act itself, which also has its mode, species and order, the privation of which is essentially sin. Hence it is clear both how sin is privation of mode, species and order, and how it destroys or diminishes mode, species and order.
This suffices for the Replies to the first two Objections.
Reply Obj. 3: Mode, species and order follow one from the other, as explained above: and so they are destroyed or diminished together.