Simple logical refutation of the Arminian theory of simple foreknowledge
The open theist William Hasker has presented a masterful logical argument that shows the incoherence of Arminian simple foreknowledge with its belief in libertarian free will. This argument can be found in the book The Openness of God by Clark H. Pinnock et. al. (1994), p. 148. Since Hasker has done such a masterful job of showing the incoherence of the Arminian position, I would like to share his argument here.
Suppose that there is a person known as Clarence who is addicted to cheese omelets. Will Clarence have a cheese omelet for breakfast tomorrow morning, or won't he? The argument proceeds as follows:
1. It is now true that Clarence will have a cheese omelet for breakfast tomorrow. (Premise)
2. It is impossible that God should at any time believe what is false, or fail to believe anything that is true (Premise: divine omniscience)
3. God has always believe that Clarence will have a cheese omelet tomorrow (From 1, 2)
4, If God has always believed a certain thing, it is not in anyone's power to bring it about that God has not always believed that thing. (Premise: the unalterability of the past)
5. Therefore, it is not in Clarence's power to bring it about that God has not always believed that he would have a cheese omelet for breakfast (From 3,4)
6. It is not possible for it to be true both that God has always believed that Clarence would have a cheese omelet for breakfast, and that he does not in fact have one (From 2)
7. Therefore, it is not in Clarence's power to refrain from having a cheese omelet for breakfast tomorrow. (From 5,6). So Clarence's eating the omelet tomorrow is not an act of free choice (From the definition of [libertarian] free will)
What this argument shows is that it is logically impossible that God should have foreknowledge of a genuinely free action. It follows from this that if there are actions that are free in the libertarian sense, it is logically impossible for God to know in advance how such actions will turn out.
Hasker then continues by stating that the best evasion from this argument that he has seen so far states that God's knowledge of what Clarence will do does not cause Clarence to eat the omelet (Openness, p. 149). However, he similarly states that althought this may be true, it is irrelevant to the argument as presented, which does not make any claim to the effect that God's beliefs are the cause of human actions, which I concur. The main point of this argument is to show that human actions according to the simple foreknowledge scheme cannot be made by libertarian free will, which undercuts the entire focus of the Arminian belief system. This logical refutal of Arminian simple foreknowledge is thus valid and sound, and thus Arminianism is rendered philosophically incoherent.