I would start with The council of Orange II tells us "that grace is preceded by no merit. A reward is due to good works, if they are performed; but grace, which is not due, precedes that they may be done."
The Council of Trent session 6 Ch 8 "none of those things which precede justification, whether faith, or works, merit the grace of justification for it is by grace...."
Notice how Trent went even further than the reformers to include faith too, this that faith dosnt even merit justification. That is because grace comes before that faith!
1) Eternal Beatitude surpasses our natural capacity
2) Since we can not attain eternal life by our own natural powers we must be predestined to that end by God directed by God as an arrow is directed by an archer. *(This does not contradict free will or that man plays a role)
3) Man can resist efficient grace but it remains in potency. (Calvinist believe in irresistible grace)
4) All men are given sufficent grace; but, it only remains in potency.*
5) Gods love is the cause of love in others. If not than some love would come from the lesser and not the greater.
6) Nothing is directed to an end unless the will for that already exist.
7) God doesn't cause things he hates but permits it for the greater good. (Calvinist believe God causes)
8) God is not determined by mans sin, God does not cause sin he is un-moved.
9) Gods eternal decree includes both the permission to sin and the punishment of sin without regard to future demerits. God remains unmoved.
10) God has two wills, antecedent will (what God wills in isolation) such as freewill without any other consideration. And Consequent will (after all things considered in light of the whole)
11) God wills the best goodness as a whole, not in individual parts.
12) God made the universe best as a whole, he did not make each creature best but one better than another.
13) Gods goodness could not be represented by one creature alone, He produced many some what is lacking in one can be supplied by another. (The existence of one rose *is good but many color roses are better.)
14) God wills some things to fail to manifest His goodness the greatest possible extent possible if not much good would not exist such as the patience of a sufferer if no injustice.
15) God permits sin, and then punishes sin by abandoning man and leaving him without grace all within His eternal decree.
16) God with holds grace and hardens hearts does not change or determine God b/c He is willing punishment while willing to permit sin. God is pure act.
17) Thus Gods will to give grace, punish those who reject His grace imply no change in God.
18) God antecedently wills all to be saved but consequently wills the salvation of the elect.
19) With sufficient grace mans power remains in potency with efficacious grace mans power to resist remains in potency.
20) Anyone who performs a single act does so by efficacious grace.
21) While God requires faith and works He brings about the faith and works by efficacious grace.
22) ALL MANS GOOD IS FROM GOD!
23) Efficacious grace can be divided into operating grace and cooperating grace.
24) With operating grace God moves mans will to do good.
25) With cooperating grace God causes man to freely chose the good.
26) Efficacious grace causes man to freely desire and chose good.
27) Man is only able to choose good b/c God continues in his will, making it calls of performing.
28) The will remains free even though the wills movement is caused by God b/c the determination of man is what's free.
29) God assist us by strengthing our wills so as to contain the act and then grants us the capability of operating.
30) MERIT] is the effect of efficacious grace.
31) If God as the primary cause does not apply the will to act secondary cause than some good does not come from the source of all good the greater would come from the lessor.
32) God does not will the destruction of the blind (Calvin) He wills to permit them to resist His grace.
Confused? I will try to answer any question but I will be off for awhile.
I really recomend "The Mystery of Predestination" according to scripture, the church & St. Thomas Aquinas by John Salsa!