We’re blogging through St. Thomas Aquinas’ Compendium Theologiae, sometimes called his Shorter Summa. Find the previous posts here.
Not only is there no imperfection in God’s infinity, says Thomas in Chapter 21 of the Compendium Theologiae, but He is necessarily more perfect than anything finite. And this has an obvious consequence:
The further inference clearly follows that all perfections found in anything at all must originally and superabundantly be present in God. Whatever moves something toward perfection, must first possess in itself the perfection it confers on others.
For example, a hot griddle can transfer heat to bacon, but a cold griddle cannot. A burning flame can set something else on fire, but cold embers cannot. However, this principle is more general than it seems. A common unlit match is not on fire itself, but still has the power to set something else on fire; and that’s really what Thomas is after here. Consider the majesty of a mature live oak, which consists of its size and the breadth of the area that it shades. God does not, in fact, have size or breadth or branches to shade things; but He has the power to bring about these things. It’s in this sense that the majesty of the oak is present in God:
Thus a teacher has in his own mind the knowledge he hands on to others. Therefore, since God is the first mover, and moves all other beings toward their perfections, all perfections found in things must pre-exist in Him superabundantly.
Besides, whatever has a particular perfection but lacks another perfection, is contained under some genus or species. For each thing is classed under a genus or a species by its form, which is the thing’s perfection. But what is placed under species and genus cannot be infinite in essence; for the ultimate difference whereby it is placed in a species necessarily closes off its essence. Hence the very ratio or description that makes a species known is called its definition, or even finis.
A thing’s species tells you what kind of thing it is; and by being that kind of thing, it isn’t any other kind of thing. Mankind, per the usual scholastic definition, is a rational animal: animal is the genus, rational the difference, and rational animal the species. Men and women are rational animals, as distinguished from all other kinds of animal. The genus plus the specific difference is called the definition of the species, that which makes it finite.
Clearly, then, if God lacked some perfection found in creatures you could place Him in some genus with the difference that he lacks such-and-such a perfection; but Thomas ruled that out chapters ago.
Therefore, if the divine essence is infinite, it cannot possess merely the perfection of some genus or species and be lacking in other perfections; the perfections of all genera or species must be in God.
So there you go.