Sr. Thomas Mary, O.P. writes:
Continuing a commentary on THE SECRET OF MARY
by St. Louis Marie de Montfort
THE SECRET OF MARY AND PREDESTINATION
These brief thoughts will offer an initial probing of the mystery of predestination which has been revealed in Sacred Scripture, taught as a doctrine of the Catholic Church, and as explained by St. Thomas Aquinas.
He predestined us in love to be his sons through Jesus Christ,
according to the purpose of his will, to the praise of his glorious grace
which he freely bestowed on us in the Beloved. . . .
In him, according to the purpose of him
who accomplishes all things
according to the counsel of his will,
we who first hoped in Christ
have been predestined and appointed
to live for the praise of his glory (Eph 1:5-6;11-12).
In order to come to an understanding of predestination, it is necessary to appreciate the providence of God in which it is grounded. God, in creating the universe and all creatures, did so for a purpose. To accomplish this purpose our heavenly Father has a wise and intelligent plan, often called the Divine Government or Divine Providence, by means of which He is guiding all creation towards its ultimate goal. Providence, St. Thomas teaches, is the plan pre-existing in the divine mind, that orders things to their end.
Now the end for which we have been created is to see and glorify God and to enjoy the unending happiness and love of the blessed Trinity.
Theologians speak of two distinct moments in the divine providential governance of the universe: God is present in all things that exist by preserving all things in being (conservatio); and secondly, by concurring with all things in their activity (concursus). This means that God exists in each person and thing as the very Cause of its existence, and simultaneously, is constantly and immediately involved in the activity of everything in the created order. If God were not present sustaining all creation and each creature in its existence and ongoing activity, it would immediately cease to exist. Consequently, nothing escapes or falls outside the scope of God’s providence. 
But this does not mean that God takes away our freedom; rather, God’s providential governance of the universe makes our free activity possible. It is not that we do our part and God his. We would not even have a part at all, nor would we be able to carry out the part we do have without God’s intense and permanent engagement with us all the time. God is not in competition with human freedom; rather he is the Cause of it. 
God’s Providence is always at work creating the possibility and conditions for realizing his divine purpose of bringing his creatures to endless bliss in divine life and love. The element of divine providence that concerns our advancement toward this goal of communion is Predestination. 
For those whom he foreknew he also predestined
to be conformed to the image of his Son,
in order that he might be the first-born of many brethren.
And those whom he predestined he also called;
And those whom he called he also justified;
and those whom he justified he also glorified (Rom 8:29-30).
Catholic Doctrine defines predestination in this way:
In his Summa Theologiae St. Thomas discusses if it is fitting that God should predestinate human beings? He answers that since every detail of the universe falls under Divine Providence, which is the guidance of all things to their ultimate goal, it is only fitting that intelligent creatures should, above all, be guided to their final destiny in God. This is because the goal of eternal life exceeds the ability of human nature, indeed it surpasses the nature of any creature. Now when an end cannot be reached one’s natural power, then one has to be sent there by a higher power, just as when an archer shoots an arrow to a target, it has to be lifted up and sent there by the archer. A creature of intelligence, capable of eternal life, can only be brought there as one lifted up and sent by God. Just as the existence of the creature has been anticipated in the mind of God, chosen in Christ before the foundation of the world (Eph 1:4) so too, the planned sending of a rational creature to its goal of eternal life pre-exists in God and is called predestination, and is one part of providence. 
The teaching on predestination begins in the Old Testament. There God reveals that the divine choice is primary, a choice that constitutes the Jewish people as unique and beloved. Any choosing of God by the people is “secondary to God’s creative choice of them.” The reason for God’s choice is His love.
God’s choice is salvific. It has a purpose: “it seeks man’s salvation by professing God’s mercy to which man is called to respond in obedience.” God’s predilection extends into the New Testament where Christ is the Beloved, the Chosen One in whom we also are chosen before the foundation of the world (Eph 1:4).
Just as God in his Providence has made everything we encounter in the universe with great variety and of varying degrees of quality and worth, so God places in his creatures a great variety of gifts and graces according to the measure of Christ’s gift (Eph 4:7).  St. Thomas comments that the failures and evils of some things in the world show forth more clearly the greatness and goodness of other things. God, who is the absolutely Supreme Good and the Source and Cause of goodness in all other things, does love some more than others, but in a different manner than we do. We love others because they are good; when God loves another more he wills and endows the other with a higher good. God’s “love as creative is the ground of any inequality, since those that are loved better are those to whom he wills more good, so that the reason why some are better than others is that God wills them more good. Hence, it is inescapable that the reason for any diversity must lie in God. In the end, therefore, it is a mystery of God’s will about which it is presumptuous to pass judgement, for the only possible judgment is his.” 
St. Thomas follows St. Augustine who teaches that we are chosen not because “we were going to be of ourselves holy and immaculate, but he chose and predestinated us that we might be so,” for the whole work of grace is a divine gift. St. Augustine adds that our “predestination is according to the purpose, not ours but [God’s] who works all things to such an extent as that he works in us to will also.” In other words we are elected not because we are holy, but our holiness is the result of our election. In his commentary on the letter to the Romans, St. Thomas regards, as does St. Paul, the passage from Exodus, I will have mercy on whom I have mercy (Ex 33:11) as decisive; . . since justice does not arise in what is of pure mercy. 
God has manifested his goodness in the creation of the universe and the creation of all creatures, including ourselves. If the purpose of his plan and providence is to bring all creatures into his glory, and if God’s will is infallible, how is it possible that some do not reach this glory?
The point at issue is how to reconcile God’s universal will to save all with the possibility that all may not saved. St. Thomas distinguishes between God’s antecedent will – his will that all be saved, and God’s consequent will – whereby although he in no way wills the evil of sin, he wills the punishment of sin and permits some to be lost which is expressed theologically as reprobation. God wills to manifest his goodness and mercy in those whom he predestines; he manifests his justice in those whom he reprobates by punishing those who refuse his grace. 
St. Thomas makes the distinction between the cause of reprobation: the moral fault which begins from the free decision of the one who abandons sufficient grace and is rejected; and the cause of predestination: the gift of efficacious grace freely accepted and promise of future glory. 
In the past the doctrine of predestination gave rise to a false teaching called double predestination. It said that the doctrine necessarily included the teaching of reprobation as a positive determination to sin and an unconditional predestination to damnation. Semi-pelagianism, Jansenism, as well as Luther, Zwingly, Calvin, and others contributed to this erroneous opinion. It was condemned both by the Council of Orange (529) and the Council of Trent (1545-1563). Such a false idea is a contradiction to the absolute goodness of God. No one is predestined to damnation; God gives sufficient grace to all. But some may misuse, abuse, or refuse His gift of grace. 
In summary the Church teaches that:
(1) God wills the salvation of all men.
(2) God gives sufficient grace to all to attain salvation
(3) There is no predestination to evil as a final end nor to evil deeds.
(4) Christ died for all men without exception. 
It is only in Christ, who is the grace of God, that the true meaning of election is discovered. It is in him that the whole family of man is elected; this is the grace prepared before all time, and shown forth in the Incarnation. Predestination is [best seen] as the total inclusive act of redemption, which has a history and which reaches down to each man and by which each is related to the sacrifice of the Cross. . . . [God] by his gracious decision invites men to himself in Christ. Properly speaking Christ is the Elect, all else is willed for him, and in him men are elected. 
Sr. Thomas Mary, O.P.
2. The Encyclopedia of Catholic Doctrine, ed. R. Shaw, s.v. “Providence,” by A. De Noia, OP.
7. St.Thomas Aquinas, Summa Theologiae, Ia, q. 23, a.1.
8. Ian Hislop, OP, Introduction to Blackfriars Summa Theologiae, vol. 5, p. xix.
9. St. Thomas Aquinas, Summa Theologiae, Ia, q. 23, a.5.
10. Ian Hislop, OP, Introduction to Blackfriars Summa Theologiae, vol. 5, pp. xxii-xxiii. See also Ia, q. 20, a.4.
11. Ibid., p. xx; see also Ia, q. 23, a.5. See St. Augustine, Nicene & Post-Nicene Fathers, vol. 5, “A Treatise on the Predestination of the Saints,” chap(s). 35, 37 (reprint ed., Edinburgh: T & T Clark; and Grand Rapids, Mi.: Eeerdmans, 1991).
12. St. Thomas Aquinas, Summa Theologiae, Ia, q.23, a.4. ad 3. See also Ia, q. 19, a.6.
13. Ibid., Ia. q. 23, a.3.
14. The Encyclopedia of Catholic Doctrine, s.v. “Providence,” A. De Noia, OP.
15. New Catholic Encyclopedia, 2nd ed., s.v. “Predestination (in Catholic Theology)” by A.G. Palladino.
17. Ian Hislop, OP, Introduction to Blackfriars Summa Theologiae, vol. 5, p. xxiv.