# Disproving freewill

1. Sep 13, 2006

### michael879

I heard this paradox a while ago that is only a paradox if there is free will. Ill write it once I can find the exact details later.

Does a paradox that only exists if theres freewill count as a proof against free will?

2. Sep 14, 2006

### Royce

Depends on the paradox and its validity. If it is valid and true then it would logically prove free will untrue and/or invalid.

3. Sep 14, 2006

### michael879

Its a game theory thought experiment in which there are 2 players. One player predicts the choice that you will make between either choosing box B or choosing both A and B. He can predict with 100% accuracy. There is $100 in A no matter what the prediction is but if the prediction is that you will choose just B, he puts$1000 in B. You then make your choice and keep whatever is under the box(es) you chose.

If he predicts B and you choose B you get $1000. If you choose A and B you get$1100. If he predicts A and B and you choose B you get nothing. If you choose A and B you get $100. The question is, after he has made his prediction, what should you choose? One argument is that choosing A and B will always get you$100 more than just B. However the other argument is that if you choose A and B, he would have predicted you choosing A and B and you will only get $100. If you choose just B he will have predicted it and you will get$1000. Both of these arguments make sense. Also, this paradox exists as long as the predictor can predict with 55% accuracy or greater. This makes it more than a thought experiment since it would be easy to make a real experiment out of it.

This only seems to be a paradox however under the assumption of freewill. Watching someone else play the game, you will see them make whatever decision that predictor has predicted. They will either end up with $1000 or$100. The paradox only really exists when you put yourself in the game and can't imagine not having freewill yourself.

4. Sep 22, 2006

### moving finger

I don't see it as a paradox - it's simply a dilemma.

"What you should choose" depends on whether you believe the premise that the predictor can accurately see the future (and is not simply making lucky guesses).

If this premise is true, then what is in box B is determined by your choice, hence you would be foolish to take both boxes (because by definition box B will be empty if you take both boxes, and you will get just the $100 in box A). However if the predictor is simply making lucky guesses (and he cannot in fact see the future), then what is in box B is what it is and is NOT determined by your choice, and you would be foolish to NOT take both boxes (because no matter what he has put in box B, you will always get$100 extra if you take box A as well).

Thus, it's up to you - do you believe the predictor is genuine, or not?

I don't see that this has anything to do with free will - there is no inconsistency in the notion that we choose according to free will, but at the same time someone is able to know what we will choose.

Best Regards

Last edited: Sep 22, 2006
5. Sep 22, 2006

### HallsofIvy

If the paradox which can exist only if there is freewill, then the fact that it exist proves freewill!