I got asked the question about Predestination as I did a bible study with a fellow Catholic on John 10. Molinism seems to be the easiest explanation, but at the same time, I didn't want to give in because I want to be a Thomist.
So I said I'd get back to him, and I read this and thought that I could be a Thomist or a Congruist.
I made this chart to help place theologies on a spectrum:
Two blog posts I've found quite helpful are these:
"All Catholics, as we have seen, believe in the necessity of grace for all supernatural acts, and therefore also, since God desires the salvation of all, they hold that He offers to all grace, really and abundantly sufficient for their salvation. They further maintain that the will always remains free to reject grace or to correspond with it. But when we inquire into the nature of the distinction between efficacious and sufficient grace, Catholic theologians give different answers. We begin with a general definition which may suffice for the understanding of the question in dispute. A sufficient grace is one which merely enables the soul to perform a supernatural act; an efficacious grace is one which does really effect the purposes for which it is given. Thus Judas received sufficient, Peter efficacious, grace for conversion: in other words, grace was given capable of converting Judas, but to Peter grace which actually did convert him. The question is, whence does the effi cacity of grace proceed ?
The Dominican theologians defend what is usually called the Thomist system of grace, because those who hold it allege that it is in substance to be found in the writings of St. Thomas Aquinas. This theory may be stated in the following propositions:—
(1) Second causes act only so far as they are determined to act by the first cause—i.e. God. Hence it is not enough to say that the power to work out our salvation comes from God. He also moves to the good action itself, and the existence of two kinds of grace must be admitted—viz. sufficient, which merely enables the recipient to act; and efficient, which is always followed by, and, indeed, produces the action.
(2) God sincerely wishes all men to be saved, and offers to all the means of salvation. But He wishes some to be saved absolutely, and considering all the circumstances ; others, only on certain conditions which are not realised. To the latter He gives sufficient, to the former efficacious, grace.
(3) In either case grace is given without any claim or merit on man's part.
(4) There is an intrinsic ditference between sufficient and efficacious grace— i.e. between the graces in themselves—so that it is always true to say that a man consented to grace given because it was efficacious: never true that the grace was efficacious because the man consented.
(5) Man always remains free and capable of merit under efficacious grace: free and responsible for his demerit with merely sufficient grace. For God as the first cause in no way interferes with the second cause, but, on the contrary, moves each second cause according to it's nature, so that beings with free will do not cease to be free because efficaciously moved by God. Sufficient grace gives full power to act, so that a man is perfectly responsible if he does not exert the power; while efficacious grace leaves perfect power of resistance. The reader will perceive the extreme difficulty, or, as the adversaries of Thoniism would say, the impossibility of reconciling this last with the foregoing propositions; but the fact that the Thomists do honestly hold the last proposition places a wide gulf between Thomism on the one hand, Calvinism and Jansenism on the other.
The three first of the Thomist propositions are admitted by that large number of Jesuit theologians known as Congruists, but they make the efficacity of grace depend, not on anything in the grace itself, but on the fact that it is given under circumstances which, as God foresees, are suitable to the dispositions of the recipient. He foreknows what all creatures would do in all possible circumstances—in what combination of circumstances they would accept or reject grace. If He decrees their predestination absolutely he gives them grace in circumstances under which they will certainly correspond to it; otherwise He confers grace which is in it self perfectly sufficient, but which they will certainly reject. Congruism has the advantage of admitting the full force of scriptural texts which attribute the whole difference between sinner and saint to the grace of God, while at the same time there is no difficulty in reconciling it with belief in the freedom of the will." -Thomas Arnold "A Catholic Dictionary" p 383-384
I now feel I understand this issue much better, and I will tell him that as a Thomist I believe that God gives his elect efficacious grace which they accept (even though they could reject it) and so are preserved by God and he knows them by name. While they can reject his efficacious grace, they don't because it goes against their nature which God is making righteous, in the same way that a person's nature is to sleep after a long day at work, even though theoretically they could stay up all night.
I could also say to him that as a Congruist I believe that God ordains a world in which his elect will accept his efficacious grace and that the choice of their will makes it infallibly efficacious which ultimately was changed by the circumstances of creation which God brought about in the first place.