Optical illusions, free will, and omniscience

Here is a link to a picture of the 'leaning tower illusion'. The two towers are really identical, but the brain expects that the second tower will lean more because of the way the brain processes perspective. Because of this expectation, we actually do see the second tower lean more.

It's arguable that we're making a similar kind of mistake when we think that free will is contradicted by God's foreknowledge of how we will choose - we're being misled by the tools we use to predict the future.

How do we predict the future? We can categorise any of our predictions into one of three categories:

1. Pure chance. We can't figure out a pattern. E.g. a coin flip.
2. Probability. You're trying to predict something that's somewhat chaotic but you can still see a pattern. E.g. what teams have the greatest chance of winning a championship.
3. Determinism. Because nothing else is possible. E.g. whether gravity will pull a rock to the ground.

These are the only three categories we know about when it comes to prediction.

For us to know the future with certainty means using category 3 thinking, which is determinism. The way it works is that you narrow down all possibilities so there's only one possibility left, and that's how you know.

So when we think about God predicting our choices we imagine God using category 3, and narrowing down (to one) all possibilities for how we will choose, because it's the only way of predicting something that we know. And it's true, such a thing would take away free will.

But why must God's foreknowledge use category 3? Couldn't God have some other way of knowing stuff, because He's an all powerful God? One that doesn't narrow possibilities down to one?

One idea of how God's foreknowledge isn't in category 3 is that when God predicts our choices He has an 'intuitive' understanding of how people will choose, that's right, but which is never explained 'intellectually'. So God may not know 'because of reason A, B, and C, Sally must go for a walk', only 'in this situation, Sally will go for a walk'. Because God doesn't account for Sally's choice any further, God can know that Sally might have acted differently, because God hasn't explained Sally's choice completely. This is an attempt at a 'non category 3' type of prediction.

So it's fair to say we could be tricked into thinking that God's foreknowledge takes away free will because of how we predict the future. But our techniques for knowing the future aren't necessarily God's techniques.

Another interesting thought on this is that the 3 categories don't apply to free will itself, assuming free will totally contradicts determinism. So it wouldn't be surprising if there's a fourth category of predicting, because (incompatibilist) free will requires another category (of something) to 'work'. This opens up the idea of a fourth category of predicting, as well.