St. Thomas Aquinas used the parable to show that the master can give some more than others.
Except that in the parable they all got what they needed, even though some got more than what they needed.
When it comes to predestination, though, Aquinas believed that God simply doesn’t give to all men what they need to achieve eternal happiness, this is why he said “ANYONE reprobated by God CANNOT acquire grace” - Summa Theologiae, First Part, Article 3, reply to objection 3
We ain’t talking about people predestined to have greater glory in Heaven here, nor are we talking about horrible sinners who come to repentance at the end (Rudolf Höss). We are talking about some people, the reprobates, simply passively omitted from a genuine salvific offer.
So I stand by my point when i said that Aquinas had misused that parable.
Because while God doesn’t owe salvation to everyone, he has to make salvation concretely achievable by everyone if we are required to consider him all-loving, just and merciful.
Saying that a merciful God creates some people and simply doesn’t wish them salvation before them having done anything is tantamount to talking about a chaste prostitute. Nonsense.
We would have a Janus bifrons kind of “god” who is both a merciful father to the elect and a spiteful goblin to the reprobate “for no reason except his divine will” (Thomas dixit).
It is factual. God did not create mankind in a state of perfection but journeying. A person cannot share in the divinity without manifesting charity because sharing is to be like God. In order to allow for that sharing, God gave free will.
All true, except that, per Aquinas and the classical thomists, no man can FACTUALLY (so let’s avoid all the “sufficient” Grace stuff here, because as i said that Grace only serves the purpose of making you accountable for your sins, according to the thomists) manifest charity if God hasn’t predestined him to do it. And no elect would ever have manifested charity if God hasn’t arbitrarily picked him up from the “massa dannata” of poor schlubs who have been created for no other reason than to allow their eternal ruin.