A bit of an eye-catcher, that title, isn't it? Hear me out; it's actually not much of a stretch.
One of the more common objections I hear to Arminianism/Wesleyanism/Molinism (I don't want to keep typing that; let's shorten that to "Arminianism", shall we?) is that "the only logically consistent Arminian is an Open Theist".
Why? Why is the only consistent Arminian an Open Theist, according to them? They contend that since God "peers into the corridors of time" and does not in fact predestine every act (by the way, that is not an entirely accurate understanding of any of the three traditions, at least as classically understood), there is no way that He can know the "unpredestined" future without certainty.
Before you accuse me of creating a straw man of Calvinism, understand that I have heard this argument not only from many Reformed friends of mine, but from Reformed theologians and apologists like Dr. James White.
What this says is actually far more revealing of Calvinist understandings of God's foreknowledge than of Arminian understandings. First, a few points to clarify on the other three positions:
In the three non-Calvinist traditions, classically understood, God in fact DOES predestine everything. God's predestination, however, is based upon His foreknowledge (Romans 8:29). There is, then, active predestination: where God actively brings things about (this is not necessarily based upon foreknowledge, although many times is or at least could be). The other type of predestination is passive: predestination that is ONLY based upon God's foreknowledge, wherein He does not actively move to alter the situation, in His Providence. The major example would be sin itself. Unlike in monergistic Reformed theology (see Westminster Confession/London Baptist Confession chapter 3, line 2), Arminianism is able to claim that God foreknew sin and therefore predestined in light of the fact of sin, rather than predestined sin without foreknowledge (which is my central contention with Calvinism; but that is perhaps another article for another time).
If the contention made by these Calvinists--the contention that God can't know anything exhaustively unless He predestines it--is true, then...well, that's what Open Theists say, too. The Open Theist simply says that God doesn't predestine everything, while the Calvinist claims that He does.
Think about that.
Both the Calvinist (at least the ones who argue similarly to Dr. White) and Open Theist claim that God can't foreknow something with 100% certainty unless God predestines it. They both agree on the NATURE of God's foreknowledge; in fact, they both agree on the Nature of God's Omniscience! Their point of contention is in the ACTIONS of God (God predestines everything, and therefore knows the future exhaustively, for Calvinism; God doesn't predestine everything, and therefore does not know the future exhaustively, for Open Theism), not the Nature of God; at least not necessarily.
What does the Arminian say?
The Classical Arminian, Molinist, and Wesleyan says that God's knowledge of the future is natural. God does not need to commit an act of predestination in order to foreknow future acts. It is simply part of God's foreknowledge, that knowledge.
Now, if Calvinists do not make the claim that "the only logically consistent Arminian is an Open Theist", it is far more possible for them to claim that they are fundamentally different from Open Theists in their understanding of the Nature (as opposed to Actions) of God.
So, respectfully, I suggest that this argument against Arminians, Molinists, and Wesleyans no longer be used.