One argument for the incompatibility of divine foreknowledge and human freedom runs as follows:

In other words it is argued that if an essentially omniscient being (God) believes prior to the actual performance of a certain action that that action will be performed at a particular time the action in question cannot be a voluntary action. The crucial premise in the argument, it seems to me, is (b) the assumption that an essentially omniscient being can know the outcome of human actions in advance of their performance, or more simply put, that essential omniscience implies knowledge of future free acts. My purpose here is to argue that this assumption is self-contradictory.