The Theological Fatalist’s Modal Fallacy

Theological fatalists posit that God’s foreknowledge of future events mean that it is not possible for anything other than what happens to happen. Since God knows every event that will happen, then aren’t those events necessary?

This mode of thinking works out like this:

1) Necessarily, if God foreknows x will happen, then x will happen
2) God foreknows x will happen
3) Therefore, necessarily x will happen

which would take the form:

□ P -> Q
P
___
□ Q

But this is a non sequitur. All that would actually follow from the premises displayed is Q. In terms of God’s foreknowledge, all that would follow is that x will happen, not that necessarily x will happen.

Theological fatalists have tried to remedy this by positing that the second premise is also necessary. So the argument would go:

1) Necessarily, if God foreknows x will happen, then x will happen
2′) Necessarily, God foreknows x will happen
3) Therefore, necessarily x will happen

which takes the valid form:

This would make the syllogism valid, but is premise 2′ true? At first glance, no. If it is necessary that God knows a specific event will happen, then God is as fatalistically determined as everyone else. It certainly seems like God’s knowledge of future events isn’t necessary, because it is possible that God could have chosen not to create the universe, meaning there would be no future events.

But the fatalist is aware of this, so they say that premise 2′ isn’t logically necessary, but chronologically necessary; meaning that since God foreknew x in the chronological past, that event (the event of God knowing x) is now necessary in the past. But, no philosopher has been able to explain how this works out and why this should be true.

In fact, we could say that since God’s knowledge of future events is contingent on those events actually happening (otherwise He would know that those events would not happen) then we could say that God’s knowledge of x, while chronologically prior to x, is actually logically subsequent to x. God knows x because x will happen. x isn’t necessitated by God knowing x.

So, in the case of free human actions, we have the ability to act in such a way that determines what God knows in the past. Take the example William Lane Craig likes to use. Jesus prophesied that Peter would deny Him. The moment before Peter denied Jesus, he had the ability to act in such a way that if he did, Jesus would not have prophesied as He did. Peter didn’t have the ability to contradict Jesus’ prophesy, because Jesus is infallible. However, Peter did have the ability to make it so Jesus would not have prophesied that Peter would deny Him.

For a really good lecture on this, and what inspired this post, listen here.