I've been reading a lot of Etienne Gilson lately, on medieval scholasticism and what the revelation of Scripture has contributed to philosophy, by giving man the answers to questions that it takes him centuries to formulate. Gilson sees one of those answers, "I am Who am," as necessary for understanding the nature of man and his liberty, and, by the way, for explaining exactly what Christians are supposed to hold regarding grace and what some, I think misleadingly, call our "cooperation" or "coadjutancy" with it.
First, Gilson pursues the metaphysical arguments of Thomas Aquinas to their astonishing conclusion: that God not only exists, but that it is his essence or nature to exist; God is the unique being who does not have being, but is, simply; if we ask what kind of being God is, the answer must be that He is Himself His own pure act of being. Next, Gilson shows that only such a being can really create ex nihilo. Plato's Demiurge does his best to rearrange preexisting matter; though he can impart form (as any sculptor can), he cannot really create, and that means he cannot create beings who possess their own acts of being, as do rational and intellectual creatures. In such a universe man does not escape the bonds of determinism. But the God who is being imparts existence itself to all things, and only such a God, since all things depend radically upon His will and His being, can create beings analogous to Himself, who indeed depend upon Him for their existence, but who also, as they exist in His likeness, can by the intellect "become" as it were all things, and judge among them, choosing one or another as they pursue the good. The upshot is that only a God who says not merely "I exist" but "I am Who Am" can create a universe wherein some beings are not determined by material causes about them; in this sense God is far more than the First Cause, but the Cause of the existence of other causes, including causes that reflect Him in His freedom from necessity.
What this means, Gilson implies, is that it is wrong to say that sinful man cooperates with the grace of God, if you mean that God and man are causes of a similar order, with God doing 99% of the work and man 1%. That is flat heresy; Thomas would have none of it. It won't do, because God is not only the cause of man's being; he is the cause of man's liberty, of man's himself being the sort of cause he is or can be. Even sinful man is free, in the sense that he remains man, whose being itself is by its own created nature able to act as a cause not determined by the material causes about him. His powerlessness is another matter; sinful man on his own will choose evil, because even if he should see the good, he will be incapable of performing it, as Saint Paul describes.
Now grace is a cause; but we must not think of it as a cause on the same order as a kick in the head; nor can we sensibly talk about sufficient and insufficient, as if grace were a push on the back of a wheelbarrow. It is akin to the gracious act of God's will that permits us at every moment to be sustained in our existence. Grace gives us everything; without grace we can will nothing good, nor perform it; just as without God's gift we cannot even be. If the angels withstood the temptation whereby Satan fell, they stood by grace, nor was it grace that God gave because He foresaw that they would stand. God willed, absolutely, that they would stand, and nothing can withstand God's will. But he willed that they would stand, and that means that they would stand freely, not resisting His grace. If Satan fell, it cannot have been that God willed absolutely that he would stand, because God's will cannot fail; nor did God will absolutely that Satan would fall. God willed conditionally that Satan would stand, yet willed that Satan be the sort of creature he was, free to fall. Our confusion about this stems from our conceiving of God's causality being like ours, because we are powerless to cause freedom in another.
If we do anything good, we do it by grace alone. On this point Thomas is quite clear. But it is still we who are acting; God redeems man who is formally free but morally enslaved, by freeing him indeed, even unto the pitch of blessedness in Heaven, where he will still be formally free but so enamored of the beauty of the infinite God that he will no longer have the power to sin. So the man on earth who sins sins freely, though he is enslaved to his passions, and that is simply another way of saying that he still possesses a human nature. When he repents, he repents freely, and it is precisely the work of grace that he should do so. Then man "cooperates" with grace not by contributing anything separate, but by rendering to God what is God's already, rendering it in a freedom which is itself a grace. If we keep before our minds the infinite distance between God as cause and every other sort of cause we see about us, then we see rather that our good will, such as it is, is truly ours, but only because God has willed that it be so, in his grace that comprehends and works through all things.
So I am trying to understand, without too many mistakes, what Thomas means by predestination. And I am wondering, given Steve's post below, whether my colleagues here across the Christian spectrum would accept this analysis. To God be the glory -- all of it.