Below is a fairly new and short (7 minute) video by the Official Website Physicist® Sean Carroll on free will. As ever, he argues that we do have free will, but it’s a compatibilist form of free will. That is, he accept “physical determinism” as totally underlying our behavior (he means “the laws of physics, which can include purely indeterminate quantum mechanics”), but says that because we cannot predict the future or what we are going to do, the laws of physics aren’t useful in helping us understand or predict our behaviors. The word “determinism” seems to be playing a big role here, conflating prediction with reality, which is why I prefer to use the word “naturalism” now.
As Sean’s said before, his view of “free will” invokes a level different from that involving the laws physics: it’s the fact, as he says, that “We can talk about human beings as agents making choices, while also agreeing that we don’t violate the laws of physics.” That is, we can’t use those laws to decide what we’ll choose in a restaurant. He argues that each human is a collection of desires, preferences, and values, which are useful in both discussing our behaviors and predicting them, but we’re also “a collections of neurons and obey laws of physics.” Thus we get the compatibility between physics and “free will”, which of course is not “libertarian” I-could-have-chosen-differently free will.
In that sense, every organism also has free will, although some lack values.
Sean, then, sees his form of free will as an emergent property of neuronal organization and evolution that has given us brains that secrete our behaviors. But he also admits that if we were able to predict perfectly what we would do, then “free will would go away.”
It is that last sentence that lays bare what I see as the problems with Sean’s argument. That’s because one thing is for sure: over the coming decades and centuries, as we learn more about the brain, we will be able to use measures of physics independent of “values and desires” to predict more and more of what we do. Already brain-scan experiments using MRI and similar crude techniques can predict what we will choose (in very simple binary-choice experiments) seven to ten seconds in advance. Does this mean that some of our free will has been taken away? This is a kind of free will destined to disappear when we learn more about science.
I do agree with Sean that we talk as if we have free will, and that we act as if we could have done things differently from what we did. As he says, this is because, “given the actual information you have about yourself, you could have acted differently, because the information you have yourself is wildly incomplete”. And that is true as well. But what is also true is that, at bottom, what we do does depends completely on the laws of physics, and our actions are “emergent” only in the sense that at bottom they rest on those laws. Any “emergence” of behavior isn’t based on some non-physical phenomenon like “will”; it is simply our inability to presently extrapolate from lower to higher levels. But there’s nothing new happening at those higher levels.
So if we’re talking about everyday paralance, I have no real problem with Sean’s conception of compatibilist free will. But I think he avoids the question that obsesses me, which I’d pose to Sean like this:
“Yes, Sean, we don’t know enough about our constituent particles and cells to make complete predictions about our behavior. But, on the physical level, isn’t it true that we could not have done other than what we did?”
I think he’d have to agree with me, because he sees no form of non-physical “will” that, given an exact rerun of physical circumstances, could somehow change the resulting behavior. Ergo I think Sean overly neglects libertarian free will, which, after all, is the form of free will that most people envision. Indeed, when I debate the issue with friends and acquaintances, they are astounded to hear that they could not have done otherwise, even if we feel we could have. Most people do seem to adhere to a form of nebulous, un-physical “will”. And if you tell them “well, given what you know you could have made a choice but you really couldn’t have,” that wouldn’t satisfy them.
Nor would it satisfy the many religionists who absolutely believe in libertarian free will. If you accept Jesus as your savior because that’s compatible with your feelings and desires, but your choice could actually be predicted if you had perfect knowledge about your body and the universe, I don’t think that Christians would say that this alone will bring you to God! For that turns every Christian into a Calvinist!
I also agree with Sean that “we have a responsibility for what’s going to happen next.” It’s a mistake to think that hard determinists like me don’t agree with the notion of responsibility. I just don’t agree with the concept of moral responsibility, for that form of responsibility rests on whether someone could actually have done otherwise, not on whether someone feels they could have done otherwise.
In the end, I think Sean is evading an important question—the one I raised above. Sure, we feel as if we could have chosen differently because we don’t have enough information to make an accurate prediction, but he doesn’t come to grips at all with the idea that given the laws of physics that underlie our behavior, there is no way we could have chosen differently. With complete information, everything is either predictable, or, if unpredictable, rests on quantum indeterminacy that has nothing to do with our will.
And that makes a ton of difference when you think about crime and punishment and when you take people to task for saying “they could have chosen otherwise”. Much of our legal system depends on an assumption of libertarian free will, not compatibilist free will. Certainly all retributive punishment does. And recognizing this fact can and should create big changes in both our judicial system and how harshly we judge other people. Under hard determinism, people can be viewed as broken cars. When our car is broken, we don’t think it had a choice, but we do things like repairing it or, if it’s dangerous, taking it off the road. You don’t beat it with a sledgehammer for acting badly in line because its nature was to have a wonky carburetor and and broken transmission.
Recognizing the falsity of libertarian free will also leads to a lessening of self-rebuke. Telling yourself “If I had done X, Y wouldn’t have happened” is useful only in rewiring your brain so you wouldn’t do X again. It is not useful in beating yourself up for behaving in a way that you couldn’t have helped.
I wish Sean would take on the issue in all its fullness. Compatibilist free will is different in important ways from libertarian free will, and those differences have huge consequences. (For those who think that there’s no material difference, remember the surveys in which people who are asked whether we have moral responsibility in a deterministic universe mostly answer “no”.) Well, it’s time that they know that we do live in a deterministic universe. I wish Sean would tell people that we could not have behaved differently, even if we feel we could have!
Again, he’s right when he’s talking about everyday notions, but if at bottom libertarian free will is a total illusion, I wish Sean would say it straight out.
I’m not psychologizing Sean here, but I think the big love of compatibilist free will among philosophers comes from a fear of naturalism and a fear (expressed by Dan Dennett, among others), that if we abandon libertarian free will, as we should do explicitly, society will become totally immoral. In other words, the notion of compatibilism is there to keep us in line.