Wednesday, June 6, 2012

Free will theorem

There have been some recent books on free will, such as Free Will by Sam Harris and Who's in Charge?: Free Will and the Science of the Brain by Michael S. Gazzaniga. These books give anecdotes and opinions about the neuroscience of free will. These books do not live up to their promise, and do not give us any scientific evidence for who is in charge. There are also atheists and others who argue that we do not have free will because we are controlled by the unconscious mind. I believe that these views have no merit.

I say that free will is not a scientific issue.

I have criticized Free will in the multiverse.

On the physics side, the Free will theorem claims that human free will is linked to quantum indeterminism.
The theorem states that, given the axioms, if the two experimenters in question are free to make choices about what measurements to take, then the results of the measurements cannot be determined by anything previous to the experiments.
I don't see how this theorem says anything about free will. The theorem has three plausible sounding axioms, but it also assumes a deterministic model for producing photon pairs. According to the model, the photon seem to have some random aspects that observers can see if they are allowed to make their own random choices. So the theorem shows that the models are really indeterministic.

This is all just a fancy way of saying that there are quantum experiments that look random. This doesn't mean much as coin tosses look random also, but could be deterministic if you knew more about the coin.


  1. Those who deny free will don’t seem to believe their own denials in that they make decisions every day of their lives. It feels more like an intellectual game where the object is to pose conundrums to the other side and to be cheered on by your supporters when you do.

    To me, free will is linked to understanding, in that we obviously change outcomes merely by understanding what is going on around us.

    I find it's best not to see such ideas as scientific though. They are best treated as metaphysical questions. Interesting maybe, but not resolvable scientifically.

  2. I agree that the issue is metaphysical.