I found this video from PBS Space Time, featuring Australian astrophysicist Matt O’Dowd expatiating on free will, to be singularly unenlightening. While he seems to know his physics, and tries to use it to answer the question of free will—bringing in both determinism and quantum mechanics—he winds up punting, saying that it’s a semantic issue and depends (of course!) on your definition of free will. But at the end, without having defined free will, he says that we can still say we have it because it’s an “emergent phenomenon” of our brain (“the most verifiably real phenomenon we can observe”), and, as such, is not an illusion.
But he mistakes what people like Sam Harris and me mean when we say free will is an illusion. Of course we feel we have choices, and often act as though we could have chosen otherwise—but it’s not clear if that’s what O’Dowd means by the “emergent phenomenon.” If it is, then it’s an illusion in the sense that it’s not what we think it is. Yes, we have that feeling of freedom, and that feeling is certainly real, but the illusion is that, as even compatibilists admit, we could not have done other than what we did at any moment in time. And, except for the action of any quantum events, the future is completely determined by the past.
Remember that, according to a survey of four areas by Sarkissian et al. (Hong Kong, U.S., India, and Columbia) between 65% and 85% of people believe that, at any moment, a person could have decided to do other than what she did. That is, a solid majority of people believe in a fundamentally indeterministic cosmos. Further, between 65% and 85% of the respondents say that if the Universe weren’t like that—if it were fully deterministic—people would have no moral responsibility for their actions. It is these predominant beliefs that we must address if we’re going to have a sensible public discussion of free will. It won’t do to pretend that nobody believes in an indeterministic universe and its consequent libertarian free will, for that’s not true. And, of course, libertarian free will is an underpinning of all Abrahamic religions.
But I digress. I will add only this: O’Dowd seems hung up on predictability as an important part of free will. But all of us, including hard determinists like me, realize that we will never be able to predict human behavior with 100% certainty. Not only do too many factors impact our brains and behavior, but, as O’Dowd points out, the uncertainty principle bars us from even knowing certain fundamental properties of quantum-behaving particles (although those may have a negligible effect on behavior). But whether or not we can predict behavior seems to me irrelevant about whether or not we have free will.
At any rate, O’Dowd knows his onions, but I don’t consider this 13-minute video to be any advance in the question of free will.