In thinking about God’s knowledge theologically it was customary for many years, until and including the Reformation, to distinguish between God’s necessary knowledge and His free knowledge. The distinction is obvious and natural. God’s necessary knowledge includes several kinds of truths. It is the knowledge of matters such as the truths of mathematics (for example, 2+2=4). It is also the knowledge of truths such as the whole is greater than the part and no circle can be a square. God’s necessary knowledge also includes His knowledge of all possibilities, such as possible people, the possible lives they could lead, and the whole range of possible worlds. These are known to God immediately and intuitively.
God’s free knowledge, on the other hand, is His knowledge of His decree (of that which, in His wisdom, God freely and unchangeably ordained to come to pass). That which God decrees is obviously a subset of all the possibilities that are known to Him. His decree also has its source solely in His mind and will.
In the late 1500’s a new kind of knowledge was proposed by two Iberian Jesuit thinkers, Luis de Molina (1535-1600) and Pedro da Fonseca (1528-1599). Middle knowledge (or “Molinism” as it came to be called), was their contribution to a controversy within the Roman Catholic church over grace, free will and predestination. In our own time Molinism has been proposed by Alvin Plantinga and others in connection with God’s relation to evil. I think it is fair to say that while Roman Catholic theologians have long discussed middle knowledge in their textbooks, recent interest in it has been due to Plantinga and his discussion of the topic in his book God, Freedom and Evil.
What is middle knowledge? At the center of this recent interest has been God's knowledge of possibilities involving human choice (the “counterfactuals of freedom” as they have been called). Why this innovation? Its proponents are concerned to preserve what they consider to be two vital beliefs. The first is God’s providence and total foreknowledge. The second is the idea that human beings are ineradicably free in an indeterministic sense. When we speak of indeterministic freedom, we mean that any human being, in a given set of circumstances, has the power to choose A or to choose not-A. The problem is obvious. How can this be consistent with God’s universal providential rule and His purposes of redemption?
The Molinists’ way of attempting to keep all this together was to suggest that there existed, besides God’s natural knowledge and His free knowledge, a third kind of knowledge. They argued that God also has “middle knowledge” (between the other two). What this means can be briefly explained. Given a whole array of possible worlds (that God knows), given worlds in which men and women were free in the relevant indeterministic sense, God knows what they would freely choose in every possible circumstance. God has knowledge of all such possible outcomes. If placed in one set of circumstances, God knows what Jones would freely choose. If placed in another set of circumstances, God knows what Jones would freely choose. This is true for all possible people and all possible circumstances. God has this middle knowledge by inspection of all the possibilities that the free will of each person might choose.
In His power and wisdom, He chooses that possible world, that total combination of individuals and circumstances, whose expressions of free will best serve His purposes. Thus, God’s omniscience is preserved, and human free will is preserved. The moral evil that occurs in the chosen world is not the direct responsibility of God but of those creatures who exercise their choices in a malevolent fashion.
What Are The Implications of Molinism?
We need to emphasize that the view of free will held by Molinists both ancient and modern is what is often called “libertarianism” or “indeterminism.” By contrast their opponents, in the Roman Catholic Church and in the churches of the Reformation, have held views of human freedom that are deliberately consistent with God’s decree of all that comes to pass and the irresistibility of His grace.
What About Biblical Arguments for Molinism?
Insofar as its proponents sought direct biblical support for middle knowledge, they used the example of David at Keilah recorded in 1 Samuel 23. At this point in the biblical narrative, the Philistines were attacking Keilah. David asked the Lord if he should go to Keilah to fight the Philistines, and the Lord said that he should. David’s companions were fearful and so David enquired a second time. At Keilah, fearing that Saul would attack him there, David asked the Lord whether Saul would come to Keilah. At this point, we read the following conversation:
And the Lord said “He will come down.” Then he said “Will the men of Keilah surrender me and my men into the hand of Saul?” And the Lord said, “They will surrender you.” Then David and his men, who were about six hundred, arose and departed from Keilah, and they went wherever they could go. (1 Samuel 23:11–13)
To the minds of the Molinists, this incident showed middle knowledge at work, for it showed that the Lord knew what would happen if a certain free action occurred (they assumed that David and the other participants were acting with free will in the libertarian sense). God knew that if David freely stayed at Keilah, then the Keilahites would freely surrender him. So David freely took evasive action, and Saul freely gave up the expedition against David when he learned of what David had done. God knew all of this (and much more besides) by His foreknowledge.
What Is Wrong with Molinism?
Since the Reformed held that all that occurs is unconditionally decreed by God and that men and women are responsible for their actions, they saw no need for a third kind of divine knowledge, a middle knowledge, which depended upon God foreseeing what possible people would freely do in certain circumstances. The Reformed interpreted the Keilah incident differently. God did not simply see what Saul would do; He ordained that Saul would come down if David remained. He ordained that David would depart from Keilah upon hearing what Saul would do. And He ordained that Saul would change his mind.
Not only is middle knowledge unnecessary to an all-knowing, all-decreeing God, but the Molinists’ conception of free will makes it impossible for God to exercise providential control over his creation. Why? Because men and women would be free to resist His decree. God can only bring to pass the actions of free agents via His middle knowledge of what they would freely do if . . .
Further, given the Molinist view of freedom, it is impossible for God to bring about the conversion of any person by the exercise of His effective call, for in the view of the Molinists it is always possible for an individual to resist God's grace. Men and women must freely cooperate with what God says and does if they are to become Christians. God’s grace is always resistible. Reformed Christians have no good reason to accept the speculative concept of middle knowledge and strong reasons to reject it.
In conclusion, we may say that there is much that is interesting and puzzling about Molinism, but the Reformed response to it has been—and should continue to be—that not only are there unresolved difficulties in the idea of middle knowledge itself, it is also an unnecessary speculation. Scripture scarcely mentions anything that may be thought to give support to Molinism, while teaching perfectly clearly that God works all things, even the evil actions of people who act with full responsibility, after the counsel of His own will. As Peter said on the Day of Pentecost, Jesus was “delivered up according to the definite plan and foreknowledge of God” and lawless men crucified and killed him (Acts 2:23).