We proceed to the fourth article thus:

1. It seems that privation of mode, species, and order is not the effect of sin. Augustine says (De Nat. Boni 3): "where these are great, good is great; where these are small, good is small; where these are absent, good is absent." But sin does not take away natural good altogether. Therefore it does not deprive us of mode, species, and order.

2. Again, nothing is the cause of itself. But sin is the privation of mode, species, and order, as Augustine says (De Nat. Boni 4, 36, 37). Such privation is not then the effect of sin.

3. Again, different sins have different effects. Now mode, species, and order are different. The privations of them are therefore different also. The privations of them are therefore the effects of different sins, not the effect of each sin.

On the other hand: sin is in the soul as sickness is in the body, according to Ps.6:2: "Have mercy upon me, O Lord; for I am weak." Now weakness deprives the soul of mode, species, and order. Therefore sin deprives the soul of mode, species, and order.

I answer: as we said in Pt. I, Q.5, Art.5, every created good possesses mode, species, and order because it is a created good, and because it exists. Every being and every good is conceived according to some form, and its form determines its species. Now the form of any thing of any kind, whether of a substance or of an accident, has a certain measure. For this reason it is said in 8 Metaph., text 10, that "the forms of things are like numbers." Each thing has thus a certain mode, according to its measure. The form of each thing, finally, determines its order in relation to other things. Thus the degree of the mode, species, and order of things varies according to the degree of the good which is in them.

There is a certain good, with its mode, species, and order, which belongs to the very nature of man. This is neither taken away by sin, nor diminished by it. There is also good in the natural inclination to virtue, with its mode, species, and order. This is diminished by sin, but not entirely taken away. There is also the good of virtue and of grace, with its mode, species, and order. This is entirely taken away by mortal sin. There is, further, the good of orderly action, with its mode, species, and order. The privation of this last is essentially sin itself. The way in which sin is privation of mode, species, and order, and the way in which it deprives us of them or diminishes them, is thus made clear.

The answers to the first and second objections are obvious.

On the third point: what we have said above makes it clear that mode, species, and order follow one upon the other. They are therefore taken away, or diminished, together.