It is not possible for a creature to exercise complete control over another person’s (non-derivatively) free action.
If Molinism is true, it is possible for a creature to exercise complete control over another person’s (non-derivatively) free action.
So, Molinism is false.
For, if Molinism is true, there will be a possible situation where God reveals to Alice that if she were to make a request of Bob while wearing blue gloves, Bob would acquiesce to the request, but if she were to make the request while wearing red gloves, Bob would turn down the request. In such a case, by controlling which gloves she wears, Alice could exercise complete control over whether Bob acquiesces to the request.
Interestingly the same argument works against Thomism. For on Thomism, God can use primary causation to determine Bob to freely acquiesce in the request and God can use primary causation to determine Bob to freely refuse the request. God could then promise Alice that he would hear her prayers as to whether Bob agrees or refuses, and then with her prayers, Alice would have complete control over Bob's decision.
The argument doesn't work against mere foreknowledge views, open theist views or compatibilist views. On mere foreknowledge and open theism, the analogue of (2) is false, while on compatibilism, (1) is not plausible.
