I've just been reading a very thorough account of the teachings of Molina and the early Molinist Jesuits, Banez and the anti-Molinist Dominicans, and the drawn-out controversy they carried on during the time of the Congregation De Auxiliis. (You can read about the controversy here) My reading has come from an excellent book by Guido Stucco, The Catholic Doctrine of Predestination from Luther to Jansenius (Xlibris, 2014).
Up until now, I have believed that Molinism teaches a view of the will and of grace which is similar to that espoused in Arminian Protestantism, where the will is deemed to be independent from any causal factors beyond itself which might determine what it will choose. In this view, the will acts basically as a First Cause, and its decisions do not in any way flow from the providential plan of God. God can only know about them by discovering them as something coming from outside himself. Since the will cannot be caused to make any choices by anything outside itself, the good will that chooses Christ for salvation cannot be a product of grace but is produced from the native power of the will itself, Grace merely opens the door for the will to produce from itself its own goodness. Arminians hold the independence of the will so highly that some of them (such as the Open Theists) have even ended up denying that God has foreknowledge of the future, because God knowing the future would imply that our decisions are already determined and cannot be turn out otherwise than God already knows they will be. According to these extreme Arminians, God cannot know our choices until we make them, since they are First Causes and thus cannot be predicted on the basis of anything that precedes them, and thus God cannot know the future until it happens.
But I am not now sure that Molinism has taught or teaches any such ideas. Here's the basic idea of some of what Molina taught about the will, predestination, and grace, as I have understood his views from Guido Stucco's (very thorough) representation of them (so keep in mind that what this is is my interpretation of Guido Stucco's interpretation of Molina):
God has middle knowledge. "Middle knowledge" refers to God's ability to know not only what will in fact happen but everything that could possibly happen and everything that would happen if other things happened. Since that came out very confusing, let me illustrate by an example: Let's say Bob decided to go to Denny's to eat dinner. At Denny's, he ordered a hamburger. However, he could have decided to go to Red Lobster for dinner, and if he had done that he would have ordered fish and chips. God knows not only what Bob will actually do but what Bob would have done had things gone differently.
So picture God in eternity past (of course, God is not actually in time, but we can use time as a proxy for logical sequences in God's thought and will). He has before him all possibilities, all possible worlds he could create. In each of these possible worlds, there is distinct historical narrative. God chooses to actualize the possible world he prefers to all the rest. Part of what gets decided when God decides which world to actualize is who will end up being saved in the end and who will not. Consider two of these possible worlds. In Possible World A, Bob will encounter Set of Circumstances X, and through all the things that Bob experiences in that set of circumstances God knows that Bob will choose to accept Christ, persevere to the end, and receive eternal salvation. However, in Possible World B, Bob will encounter Set of Circumstances Y, and God knows that through all the things that Bob would experience in that set of circumstances Bob will choose to reject Christ to the end of his life and end up in eternal damnation. But Bob, of course, is not the only person in the world. In Possible World A, Jerry will end up deciding to reject Christ and will be damned, while in Possible World B he will be saved. Let's say that God freely decides, sovereignly and of his own good pleasure, that he will actualize Possible World A and not Possible World B. In that case, God has freely elected and predestined Bob to eternal salvation while rejecting and reprobating Jerry. God could very well have freely decided to do the opposite, or he could have actualized yet another possible world in which both Bob and Jerry would have been either saved or damned. Since God's choice was free and unconstrained, based on his own good pleasure and not drawn by any necessity outside of himself or by any merits in either Bob or Jerry which determined his choice, we can say that God's eternal decrees of predestination and reprobation were unconditional. However, Bob received salvation because he chose to accept Christ and persevere to the end of his life of his own free will. He could have rejected Christ, but it just so turned out that he didn't. God's eternal ordination of Bob to eternal salvation took into account the foreknown fact that Bob would choose to accept Christ when he could have chosen to reject him, so in that sense we can say that God's election of him was based on Bob's foreseen future choice; but since the whole historical narrative in which Bob made that choice was actualized by God freely, and God was perfectly free to actualize a different narrative, we can still say that Bob's predestination was ultimately unconditional.
The Dominicans severely attacked this Molinist teaching on a number of grounds. One of their chief complaints was that Molina was making it sound like Bob's choice to accept Christ was something Bob produced on his own as opposed to being something produced in him by grace. Molina wanted to say that both Bob and Jerry received grace sufficient to save them if they would have accepted it. In fact, Molina would even grant that perhaps Jerry might have received more graces than Bob, but he rejected his grace while Bob accepted his. The Dominicans interpreted Molina and the Molinists as saying that the difference between Bob and Jerry was not a matter of divine grace but of some difference stemming ultimately from their two wills, and they pointed out that this would make Bob's good choice a product of his own will ultimately and not of God's grace, contrary to the Catholic doctrine (see, for example, the Second Council of Orange) which strongly affirms that all good will, along with all things that lead to or are a part of salvation, are entirely a gift from God.
So the big question is, What was it, ultimately, that caused Bob to choose to accept Christ while Jerry rejected Christ? It seems to me that if the Molinists will grant that it was divine grace that made the difference here and it was divine grace that produced Bob's choice for Christ, I can see no grounds for opposing the Molinist point of view. One might still quibble with bits and pieces of it, or with the terminology of its formulations, but there would be nothing in it that would be obviously contrary to anything in Catholic faith or in the Augustinian doctrines of grace affirmed by the Catholic Church. In all my reading thus far, I can't tell for sure what the Molinists were attempting to do here. I expected to find clear Arminian-type statements from the Molinists, but they keep coming short of making such statements. Granted, they sometimes talk in ways that sound less Augustinian and more "Arminian," but they never seem to actually get there. Also, they frequently make comments that sound more Augustinian than I would have expected. The concept of "middle knowledge" itself, far from implying the sort of situation where God's predestination is not the ultimate explanation for all that happens, actually seems to imply exactly that, for if our free choices came ultimately only from ourselves and were in no way produced by God, then God could not know about them except by seeing what we actually end up choosing. Middle knowledge, on the contrary, has God knowing what we would choose before we actually make a choice, which implies that our choices are not uncaused, first-causal events but are explained as parts of a larger coherent causal nexus (so that God could know exactly what we would choose). This is why Open Theists object to middle knowledge, and want to replace it instead with the idea that God knows not what will happen in various circumstances but only what could or might happen. To say that God knows for sure what would happen implies that our choices are part of a causal nexus that is ultimately set in place by God when he actualizes the universe he wants--unconditional predestination. So middle knowledge requires predestination. So long as the Molinists also acknowledge that the very structure of reality which creates the possibility of middle knowledge--the laws of logic and causal relations and in general how the world works--is not a given that comes from outside of God but is rooted, along with all of reality, in him, and so long as they acknowledge that when the will chooses to enter into a state of grace as well as to remain in a state of grace, these good choices are a product not of natural free will but of supernatural grace, then at this point I see no real theological problems with the Molinist paradigm.
So, at this point, I'm not sure I have enough information to draw a clear conclusion on this matter. What I will say is that the Molinist-Dominican controversy is more complicated than I previously thought. I agree with the Dominicans' arguments as they are directed against what they construed Molinists to be saying, but I'm not sure anymore that it's what the Molinists were actually saying. The Molinists, in turn, accused their Dominican opponents of being fatalists, of denying free will, etc., and I'm quite sure from what I've read that this was false. So perhaps the whole controversy will turn out to have been more rooted in misunderstanding than any greatly substantial or significant theological disagreement. Perhaps, to my surprise, it will turn out that nobody in this controversy was actually arguing for an Arminian-like viewpoint and that everyone was affirming a basically good Augustinian viewpoint. At any rate, what I've learned has given me a new appreciation for why perhaps the Church refrained from officially deciding the controversy or condemning the Molinists. There may not have been anything there that really warranted being condemned after all.
On pp. 194-195 of his book, Guido Stucco articulates eleven propositions put forward by Jesuit theologian Achille Gagliardi during the time of the Jesuit-Dominican controversy that Gagliardi believed to be affirmed by both the Jesuits (the Molinists) and the Dominicans. The list is very enlightening (I've added spaces between the points for easier reading, since I couldn't exactly reproduce the formatting in Stucco's book):
1) God has a distinct and perfect providence of all acts of human free will, and concurs in each of them effectively and directly.
2) The creaturely will requires help to receive the supernatural ability to act and to produce a supernatural deed in union with God's help.
3) Creaturely will is also in need of prevenient grace, so that through it, it may be stirred and dispose itself to produce such deeds. This happens not only extrinsically, through an external object/action proposed to the human will, but also intrinsically, by enlightening the mind and inclining the will to consent.
4) This prevenient help is given exclusively out of God's good pleasure and will; therefore, the beginning of faith and of Justification derives from God alone and not at all from our free will.
5) Besides this, the supernatural concurrence of God is required, so that, acting in unison with free will, it may directly produce as the first and main cause man's free determination and consent.
6) Sufficient grace, in virtue of which a man is able be [sic] converted, is one thing; efficacious grace, by which God ensures he is infallibly converted, is another. Thus, we read in Scripture expressions such as man "is drawn," "the will is prepared by the Lord," (Pr. 8:35); "God works in us the willing and the doing" (Phil 2:13). Also, according to Augustine, "This grace, therefore, which the divine generosity gives in a hidden manner to human hearts is not rejected by any hard heart" (Predestination of the Saints 8,13); "It turns a person from unwilling to willing" (Against Julian III, 122); "God does whatever he wants of the human will." All these things are true, as the human will remains free and un-violated.
7) This efficacious help derives from God's efficacious intention and from his absolute intention to convert a person. This is brought about exclusively by God's good pleasure and by nothing else: there is no other cause which is in man's power.
8) God predetermined with an absolute decree and good pleasure of his will those who will consent to his grace; only these will be infallibly saved, and nobody else.
9) There is no cause of predestination on the part of the human will.
10) Predestination involves the following: a) God prepares all the efficacious means of grace necessary for salvation; b) through it, the elect are distinguished from the reprobate, so that no one has any reason to rejoice in themselves; c) As Paul said: "It does not, therefore, depend on human desire or effort, but on God's mercy" (Rom 9:16); d) The number of the elect established by it is certain; e) No one, other than the predestined, will be saved; f) It is to be attributed to the higher and inscrutable nature of the divine mind why this person will be saved, but not that one.
11) The human will, albeit moved and stimulated by grace, can consent or dissent to it. [Footnote 109: "Serry, Historiae congregationum, (1709), 202-207. Serry found these theses in the Biblioteca Augustinina, vol. fig. H.")
If the Jesuits and the Dominicans really agreed on all of these points, then it is not easy to see why Molinism should be considered Semipelagian or "Arminian." (And note that a Jesuit wrote this list!)
On p. 198, Stucco records some comments made by Pope Paul V to the Spanish ambassador regarding why he did not make a final decision in the controversy:
I postponed making a decision in the matter of de auxiliis for three reasons: the first, in order to be conscientious, and also considering that time teaches and shows the truth about everything, acting like a great judge and censor of all things. The second, because both parties are in substantial agreement with Catholic truth, namely that God through his efficacious grace makes us act and turns us from unwilling to willing subjects, bending and changing human will. There is disagreement about that, but only concerning the manner in which God does this: the Dominicans say that he predetermines our wills in a physical manner, namely, really and efficaciously, while the Jesuits claim that he does so congruously and morally. Both opinions can be defended. The third reason is that in our day and age, in which there are many heresies, it is most appropriate to preserve and uphold the reputation and credibility of both religious orders, since to discredit either one may turn out to be greatly harmful. If we were to ask what we are to believe in this matter, I would say that we must uphold and follow the teachings of the Council of Trent, Session VI, On Justification, which are very clear and straightforward about what was the error and heresy of Pelagians and Semipelagians, as well as Calvin's. This session also teaches the Catholic doctrine according to which it is necessary for human free will to be moved, excited and helped by God's grace, and that the will can freely assent or dissent. The Council did not entertain the question of how grace works, but merely touched upon it and left the explanation alone, regarding it useless and unnecessary, thus imitating Pope Celestine, who, having, defined some issues or propositions on this matter, said he did not want to condemn or elaborate on more difficult or subtler ones. (Footnote 114: "Denzinger, 1997 a.")
From what Pope Paul V says here, and from the list of agreed-upon propositions given by Jesuit theologian Achille Gagliardi, it appears that both the Jesuits and the Dominicans agreed that the predestination of the elect is unconditional, rooted in God's sovereign purpose and not man's free will, and that while sufficient grace is given to all men to be able to accept Christ, yet God gives only to his elect an efficacious grace which infallibly converts the will and causes it to persevere to the end and so actually receive eternal salvation. Those who receive this efficacious grace will be saved, while those who don't won't be. What more could a good Augustinian ask for? There is no problem with saying that sufficient grace is given to all men to accept Christ or that the will can either accept or reject grace. Bob the elect and Jerry the reprobate have enough given to them so that, if they want to, both can choose Christ and persevere to the end. But only Bob will in fact do so, while Jerry will not, and the difference between them ultimately stems not from some native ability that Bob has and Jerry doesn't but from the predestination and efficacious grace of God which is given to Bob and not to Jerry out of God's good pleasure and sovereign mercy.
I want to quote one last time from Stucco's book. On pp. 169-170, Stucco mentions another list of propositions the Jesuits proposed at one point during the de auxiliis controversy as points in which they were in agreement with the Dominicans:
1) Man is given the help of prevenient efficacious grace, through which God brings about that man does what is good; 2) This help is a peculiar gift of God, distinct from sufficient grace; 3) This help is intrinsic to both man's intellect and will, consisting in the stimulation of both, which is to say, in the illumination of the intellect and in the motion of the will; 4) This help is supernatural and sent by God; 5) This help does not only exist on the part of the object, but also on the part of the power; 6) The motion of the will is real and precedes the application of the will to a specific action; 7) Once this efficacious help is put in place, it infallibly converts man.
Stucco mentions the response of the Dominicans to this list:
Ripalda recorded the Dominicans' satisfaction with these statements, saying that "They had no question about this convergence of views; instead, they were amazed that we agreed with them about these things, and said that if Molina and the Spanish Jesuits had said this much, there would have been no quarrel with their theologians." [Footnote 51: "Ripalda, 525."]
Again, what more could an Augustinian ask for? And yet, the two parties continued to debate, and they never did reach a mutually-satisfactory agreement.
In conclusion, my previous thinking was that the Catholic Church has clearly affirmed salvation by grace alone, but that it refrained (for whatever reason) from condemning a particular view (Molinism) which, in its logical implications, contradicts this (though it did not declare this view correct either or promise not to condemn it in the future). But now I'm thinking it may be that the Catholic Church never has refrained from condemning any Arminian-type viewpoint proposed seriously to its consideration. I should remind readers, though, that I am still in no way an expert on Molinism, and I need to do much more research before I could declare any conclusions dogmatically.
ADDENDUM 2/23/16: On pp. 298-300 of his book, Stucco provides another list by a theologian involved in the de auxiliis controversy of theological positions he thought both sides could agree on. The theologian was Giovanni Antonio Bovio, a Carmelite who leaned in favor of Molina's doctrine and was a strong defender of the orthodoxy of the Jesuit position. Once again, it is striking what Jesuit or Jesuit-leaning theologians thought that both sides could agree on (as before, I have adjusted spacing, etc.):
1) Human nature has been so wounded by the Fall, that without the grace of God healing it, man cannot fulfill the whole natural law, nor avoid all mortal sins that are committed against it.
2) The same grace of God acting through Christ Jesus, is simply necessary to perform individual acts of belief, hope, love, penance as well as any other good deeds (no matter how easy they may appear), so that they may be fitting of God and of salvation--and not just as to make them easier to be carried out.
3) The necessity of exciting, healing, cooperating, prevenient and consequent grace must be acknowledged and upheld by everybody.
4) The very beginning of our justification must be attributed to the prevenient grace of God through Jesus Christ, which is bestowed on us by God in a simply gratuitous way, not because of any of our works, not because we want it, but so that we may want it. Anything that precedes that grace plays no role or has no merit in the bestowal of God's grace or in the attainment of salvation.
5) God gives to some people only his prevenient sufficient grace, with which they may truly and properly do what is good; thus, if they do not do it, their damnation must be attributed to them alone, and in no way whatsoever to God.
6) To some people God gives not only the ability to want and to do good, but by the help of his grace which we call "efficacious" he makes sure that they most surely and infallibly may want and do that which is good.
7) Likewise, to all the just he gives the help by which they are able not to sin, not to depart from goodness and to persevere to the end, if they want to. But to the saints predestined to the kingdom of God through his grace, is given such a help that without it they couldn't persevere and unfailingly want that which is good.
8) God gives his efficacious grace without playing favorites and not even according to his distributive justice, but rather to those whom he wants and out of his good pleasure and will; therefore, the reason he gives to some and not to others lies in his hidden and inscrutable judgments, and no cause whatsoever can be assigned on man's part.
9) Through this grace, God not only leads men, but draws them, turns them willing from unwilling, agreeing from dissenting, loving from fighting; he works in them the willingness and the working; transforms their wills and inclines their heart to what he wants and when he wants it.
10) This grace is: a) That divine benefit by which all those who are liberated are most certainly liberated; b) the calling according to God's purpose, which no elect can spurn; c) a high and mysterious calling that brings about one's consent to God's law and teachings; d) a hidden and mysterious doctrine that not only inclines people to do good, but persuades us to do it--by which God not only shows us the truth, but also engenders love in our hearts, giving to his elect to know what they are to do, and to do what they know ought to be done; e) the illumination and the inspiration which not only makes apparent that which was hidden, but also makes appear sweet that which one did not love before; f) through it, God not only illuminates the mind, showing us what needs to be done, but also inspires a good affection for it, giving us most efficacious strength to our will.
11) When grace begins to operate by itself, it brings about the intended result by himself, but by simultaneously cooperating with the human will. It is for this purpose that the will is prepared by the Lord, so that by assisting and cooperating with exciting and helping grace it may freely produce acts by which the will may dispose itself and move in virtue of its own freedom towards justice.
12) Through the efficacious grace of God the human free will is not taken away; likewise, without it, man has sufficient help to which, if he wants to, is able to assent. Once it is given, the ability to assent or dissent is still in place, so that man can still resist it, if he wants to (Serry's Appendix, pp 152, 153).
On pp. 295-301, Stucco describes how Bovio tried to defend the Jesuit position from Dominican attacks. He asserted that the Dominicans had fundamentally misunderstood what Molina was saying on a number of points, and that he was more orthodox (from an Augustinian point of view) than they realized.
ADDENDUM 5/15/16: Catholic Philosopher Alfred J. Freddoso comments here on how the Dominicans (following Dominican theologian Domingo Bañez) and the Molinists agreed on the absolute nature of God's providence--that everything that happens in history, good and evil, has been specifically ordained by God to come to pass:
According to the traditional doctrine of divine providence, God freely and knowingly plans, orders and provides for all the effects that constitute the created universe with its entire history, and he executes his chosen plan by playing an active causal role that ensures its exact realization. Since God is the perfect craftsman, not even trivial details escape his providential decrees. Whatever occurs is specifically decreed by God; more precisely, each effect produced in the created universe is either specifically and knowingly intended by him or, in concession to creaturely defectiveness, specifically and knowingly permitted by him. Divine providence thus has both a cognitive and a volitional aspect. By his pre-volitional knowledge God infallibly knows which effects would result, directly or indirectly, from any causal contribution he might choose to make to the created sphere. By his free will God chooses one from among the infinity of total sequences of created effects that are within his power to bring about and, concomitantly, wills to make a causal contribution that he knows with certainty will result in his chosen plan's being effected down to the last detail.
This much is accepted by both Molina and the Bañezians. They further agree that it is because he is perfectly provident that God has comprehensive foreknowledge of what will occur in the created world. That is, God's speculative post-volitional knowledge of the created world -- his so-called free knowledge or knowledge of vision -- derives wholly from his pre-volitional knowledge and his knowledge of what he himself has willed to do. Unlike human knowers, God need not be acted upon by outside causes in order for his cognitive potentialities to be fully actualized; he does not have to, as it were, look outside himself in order to find out what his creative act has wrought. Rather, he knows 'in himself' what will happen precisely because he knows just what causal role he has freely chosen to play within the created order and because he knows just what will result given this causal contribution. In short, no contingent truth grasped by the knowledge of vision can be true prior to God's specifically intending or permitting it to be true or to his specifically willing to make the appropriate causal contribution toward its truth.
ADDENDUM 5/26/16: I have just written up another article which argues further that the Molinist position is Augustinian and in accord with Catholic doctrine and that the Dominicans misunderstood it.
Also, this article by Fr. John Hardon contains a very helpful account of the Dominican-Molinist controversy and a very helpful description of the Molinist position and its nuances and various forms.