Do We Have Free Will? Part 3: Divine Foreknowledge

So far, I’ve written about two arguments for determinism which, though not completely conclusive, present serious challenges to belief in free will. The same cannot be said of this next type of determinism. There actually is no reason for accepting it, since there is no reason for believing its premises. Nevertheless, it is a serious internal problem for Christianity. It shows that the beliefs of most Christians aren’t — as shocking as this may seem — entirely coherent.

The basic idea is simple enough: If God already knows the future, he already knows everything you are going to do. The only thing you can do, then, is what God knows you will do. And that means you aren’t free.

There are, however, certain complications here which most people are unaware of. In particular, there is the fact that knowledge does not normally imply infallibility. If one knows something (genuinely knows it, that is), then it follows that it’s true; one cannot know a falsehood. But it doesn’t follow that it had to be true.

How this relates to the foreknowledge argument can best be seen by means of an example:

Suppose that I know you well enough to be sure that you will not vote for Trump in the next election. Does that mean your not voting for Trump isn’t free? That you can’t choose otherwise? That doesn’t seem right. The believer in free will can admit that there are things one would never do, for one can freely choose to never do them. And if I know you well enough, I can know what you will do even if you are free — have the power — to do otherwise.

If you disagree with the above, it’s probably because you are interpreting the concept of knowledge in a stronger sense than normal. You may be thinking that if there is even the slightest possibility that someone does otherwise, then you can’t know what they will do. But if so, then you can’t claim to know almost anything, for there is a possibility of being wrong for most of the things we claim to know. If, on the other hand, you mean roughly what most of us mean by “knowledge,” then you must admit that one person can know the way another will act even if the other is acting freely and could, if they wanted to, act differently.

It’s helpful to know all this because there are theists who will appeal to it in order to reject the argument from divine foreknowledge. They will maintain that, just as you can know how someone will freely act, God always knows how we will freely act. This, however, ignores a crucial difference. God is supposedly infallible. Unlike human knowledge, God’s knowledge does not admit the possibility of error. And it is that which creates a problem for the theist who believes in free will.

This difference can best be understood if we think of it in terms of “possible worlds” (that is, in terms of ways things could have been). So, for example, suppose Mario believed yesterday that Luigi would do x today, that he had very strong reasons for believing it (the kind that we normally associate with knowing), and that Luigi in fact did x today. Then we would say that Mario knew Luigi would do x. However, if Luigi was nevertheless free to do something else — if he could have refrained from doing x — then that means there is a possible world in which Mario believed Luigi would do x and yet he did not do it. In other words, that’s the way things could have turned out, and this shows Luigi was in fact acting freely.

But now suppose instead that it is God who infallibly knew yesterday that Luigi would do x. To say that Luigi was nevertheless free to choose to do something else, then, is to say that there is a possible world in which God believed he would do x, yet he did not do it. But of course, that can’t be! If God is infallible, then it is not even logically possible for him to be mistaken — and thus there is no possible world in which he is mistaken. It follows that if God already knows what you are going to do in the future, you don’t have the power to do anything else. To actually be free in that case is to have the power of making God wrong.

It is God’s supposed infallibility that creates a problem for free will. And the only way to avoid it, it seems, is to deny either that there is an infallible being with foreknowledge (or more precisely, that there could even be such a being), or to deny that we have freedom of choice. Most true believers refuse to accept either of these ways out. They therefore continue to have an internally inconsistent worldview.