Peetem wrote:
If God wills all men to go to heaven, then does that mean those who achieve this goal, do so because of "regular" grace (for lack of a better term)? Or rather, does God give them "extra" grace?
The controversy over Grace has never been resolved, so according to where we sit now there are taken to be at least two orthodox ways to answer your question. The Molinists believe that Predestination is after and because of foreseen merits, meaning that God sees what one would do in all variety of given circumstances, and predestines one accordingly. The Thomists teach that Predestination is prior to foreseen merits, meaning Predestination is wholly gratuitous, and then having elected some, God gives them the path to walk. On neither view are all men Predestined to grace or glory. ("Predestined to grace" would mean being justified through baptism for a time, "Predestined to glory" means eventually actually reaching Heaven: obviously, we do not believe that all who are predestined to grace are also predestined to glory, since we can turn our backs on God.)
The "kinds" of grace involved in the two systems are also different. The Thomists believe in intrinsically efficacious grace, whereby God causes us to freely respond to the offered grace. The Molinists do not believe in intrinsically efficacious grace: on their view, God offers sufficient grace to all, and then they may or may not freely respond to it. If they do respond, then that grace can be described after the fact as efficacious, but if not, then it cannot be so described. Its efficacy is not intrinsic to it, but depends on the recipient. So while in each story, everyone gets sufficient grace and not everyone gets efficacious grace, the mechanics are completely different.
It's been...a decade?...since I read or taught about this, so I'm sure I'm both leaving out detail and getting things wrong. Check out Fr. Garrigou-Lagrange's Predestination for a super great technical discussion.