Luis De Molina, hearing his name might make you shudder, rocking slowly back and forth saying “subjunctive conditionals” and “Middle Knowledge” while watching a Dr. William Lane Craig lecture. However, Molina was an interesting figure.
First some background on Luis De Molina. He was more Protestant than you might think. Now, I’m a Calvinist, so I say this with no favorable bias towards Molina when I say he was more Protestant than Catholic, I plan on demonstrating just that below.
Molina was Tried as a Protestant
Molina was tried by the Inquisition in 1536. This was largely due to Molina not being your average Catholic. Macgregor in his biography of Molina states
much of Molina’s thought stood in direct opposition to the Catholicism of his day
Molina wasn’t in agreement with the council of Trent on justification and was actually closer to the Protestant doctrine of justification.  There is no doubt that had Molina lived longer (In a different possible world, perhaps?) he would have been excommunicated by the Pope.
Not only do today’s Arminians use middle knowledge as a better defense for their beliefs, but Jacobus Arminius himself did this (Bold and underline emphasis mine)
He knows all things possible, which may be referred to three general classes. (i.) Let the first be of those things to which the capability of God can immediately extend itself, or which may exist by his mere and sole act. (ii.) Let the second consist of those things which, by God’s preservation, motion, aid, concurrence and permission, may have an existence from the creatures, whether these creatures will themselves exist or not, and whether they might be placed in this or in that order, or in infinite orders of things; let it even consist of those things which might have an existence from the creatures, if this or that hypothesis were admitted. (1 Sam. xxiii. 11, 12; Matt. xi. 21.) (iii.) Let the third class be of those things which God can do from the acts of the creatures, in accordance either with himself or with his acts.
Arminius used Middle Knowledge to explain how God could manipulate free choices to get what he wants without necessitating any action and keeping the creature free in a libertarian sense.
God acts, preventively, on the will by suasion, when He persuades the will by any argument, that it may not will to perform an act, to which it tends by its own inclination, and to effect which the creature has, or seems to himself to have sufficient strength. By this, the will is acted upon preventively, not of necessity, indeed, but of certainty. But since God, in the infinity of His own wisdom, foresees that the mind of the rational creature will be persuaded by the presentation of that argument, and that, from this persuasion, a prevention of the act will result, He is under no necessity of using any other kind of prevention
Despite this use of Middle Knowledge, Arminius and his subsequent followers refused to take Molinism where Molina did, what is now referred to today as “Pure Molinism”.
A pure Molinist affirms a type of unconditional election, that God’s foreknowledge of what someone would do or does do is not the primary cause of God’s decree to make whatever possible world he wants.
Contra William Lane Craig,(Craig admits this in his discussion with Paul Helm. ) Molina also affirmed that God did not create a possible world with the intention to save the most people, which is closer to the Calvinist view than the Arminian one.
For Pure Molinists of today, I’d recommend Alvin Plantinga and Zachary Lawson.
Arminians will use Molina’s theories but won’t take them to their conclusion, because in reality, they’re only using and abusing Molina’s defense to avoid Calvinism, as they realize and as a Calvinist I admit, Molinism is a better alternative to Calvinism than Arminianism will ever be. I’ll leave you with this quote from Molina.
“Paul adds that God said to Moses: I will have mercy on whom I have mercy and I will have compassion on whom I will have compassion; that is, I will use mercy with whomever I wish and just as it gives pleasure to Me. And Paul concludes: Therefore, it is neither he who wills nor he who runs. but God who shows mercy…He has mercy on whom he wills and he hardens whom he wills…Therefore, neither predestination nor deprivation is according to foreseen merits, but it leads back only to the free will of God.”
 Underground Protestantism in Sixteenth Century Spain, p.55 by Frances Luttikhuizen
 Luis de Molina: The Life and Theology of the founder of Middle Knowledge by Kirk R. MacGregor (First page of Introduction)
 Ibid. Introduction (Second Page of Introduction)
 The Works of James Arminius Vol: 1: Disputation 4: On the Nature of God
 The Works of James Arminius p. 423
 Paul Helm vs William Lane Craig debate Molinism vs Calvinism: On Unbelievable with Justin Brierley
 Molina, Concordia 7.23.4 & 5.4.1
A Molinist-Anabaptist Systematic Theology by Kirk R. MacGregor
Luis de Molina: The Life and Theology of the Founder of Middle Knowledge by Kirk R. MacGregor
- Robert Godfrey on Arminius and Molina