Several readers, knowing of my interest in free will, sent me the link to the video at the bottom by physicist Sabine Hossenfelder. Thanks to all, and to Adrian, who sent the link first. My summary and analysis precede the video.

In October of 2020, Hossenfelder declared that libertarian free will—i.e., the “I-could-have-done-otherwise-using-my-volition” form—didn’t exist. I agree with her, of course, for we’re both “naturalists” and “hard determinists.” If you think matter obeys the laws of physics, which is universally accepted in science,  then there’s no room for mental lucubrations that could somehow tweak the laws of physics (Mental lucubrations are instantiations of physical law!) That’s why she (and I) think that, as far as libertarian free will is concerned, “it’s obvious that we don’t have it.”

Hossenfelder notes that some find the “freedom” in “free will” via occasional quantum jumps of particles on top of deterministic physical determinism. It’s possible that these jumps could, at any given moment, produce different outcomes in the next moment, but that of course depends on whether our behavior or thoughts are affected by quantum phenomena. (We have no idea.) But even were that true, those quantum jumps can’t come from “will”, so there is no “freedom” from physical determination of behavior. Volition is an illusion.

However, Hossenfelder is dubious about whether quantum jumps are really random phenomena: she appears to be a full-on determinist who thinks that the wave function, which includes quantum behavior, itself behaves deterministically. (This bit is way above my pay grade, but still leaves no room for some numinous “will”. I’ll let physicists argue about the “randomness” of quantum mechanics.)

Hossenfelder goes on to describe “emergent properties” like conductivity, which makes no sense unless you talk about a collection of electrons. This, however, doesn’t do away with determinism, for it is the laws of physics that produces emergent properties as the consequence of underlying laws. Emergent properties may not yet be predictable from the laws of physics, but they are all absolutely consistent with the laws of physics.

Finally, she goes on to discuss compatibilism: the view that free will and determinist can coexist happily and without contradiction. Like me, she regards this view as simply an exercise in philosophical semantics that does noting to dispel the fact that we lack libertarian free will in the classical sense. (Remember, that brand of free will is the one most accepted by people in several countries, and is of course a mainstay of Abrahamic religion as well as other forms of religion.)  Compatibilism, to me, is like religion: a “little people’s” view confected with the idea that unless people believe certain creeds, society will fall apart.

Here are the forms of compatibilism Hossenfelder presents (I note with some amusement that different philosophers find many different ways to make free will compatible with the laws of physics, and some of the forms of compatibilism are incompatible with each other).

a. ) Some philosophers say that “Human decisions are to a large extent independent from external factors and are dominantly determined by internal deliberation.” This seems confusing to me because “internal deliberations” are simply examples of “external factors,” i.e. the laws of physics acting on our bodies and brains. If you say that they aren’t, then you are a dualist who accepts libertarian free will.

b.) Hossenfelder’s chracterization of Dan Dennett’s compatibilism:  “Our ability to see probable futures–futures that seem like they’re going to happen, and then to take steps to make something else happens instead.” Those steps, of course, are also determined by the laws of physics.

c.) Another brand of free will is due to “The large degree of autonomy that our brain has from environmental factors.” This has the same problems as (a) above.

d.) Free will occurs because “our decisions follow from what we want”. And yes, we do make decisions according to what we want, because what we want is simply the result of our genes and environment and is and thus coded in our brain.  People generally act consistently with their character, because their character is consistent with their evolved and structured brains.

Hossenfelder presents the results of a 2020 survey about philosophers’ acceptance of libertarian free will vs. compatibilism vs. determinism (what I call “naturalism”). The results of the survey are given in the screenshot below, which I lifted from her video.

Most philosophers are compatibilists, which is a view that, I think, people hold because although these philosophers really do accept Hossenfelder’s claim that there is no libertarian free will, they think that some notion of free will is essential for people to be able to function without drowning in nihilism. (That’s not true.) But at least more philosophers are compatibilists than are “regular people”.  What is disturbs me is that nearly 1 in 5 philosophers (probably the religious ones) are free-will libertarians: more than are “hard determinists” like Hossenfelder and me.

She does take up the question (one I’m often asked when I lecture on why we lack free will), “Why don’t you just kill yourself since everything is more or less determined?” Her answer is a good one: those people should see a psychologist. I manage to hang onto being a hard determinist, though of course I act as if I can make free decisions. We can’t live without feeling that way because that’s just the way our brains are constructed. Perhaps the illusion of libertarian free will is an evolved trait. I can think of several reasons why natural selection, for instance, would drive us to think we make free choices, or perhaps it’s just an epiphenomenon. But I won’t wade into those waters here.

In the end Hossenfelder adds two points:

1.) The free-will problem arises because “the way we think our brain works is not compatible with the facts of science”. But the way we think our brain works is an illusion.

2.) Why does this issue matter? Because, says Hossenfelder, “free will is an inaccurate description of reality” and “makes people believe that they have more control over what goes on in their head than is really the case.”  Example: “Our brains will process input whether we want to our not; once it’s in and we can’t get it out. That’s why trauma is so hard to cope with and misinformation so hard to combat”. This, she says, is a result of our physically-mandated and evolved neuronal processing of inputs. I would add that perhaps it’s possible, through therapy, to mitigate trauma. That, of course, would be the deterministic result of a traumatized person going to a therapist skilled in this art. But no determinist claims that such external influences cannot have an effect.

Sabine closes by declaring that she’s a hard determinist and that we have no free will in the commonly-accepted sense of “libertarian” free will. It’s good to hear from a kindred spirit, though this video is fairly similar to the one she put up several years ago. Still, determinism is like atheism: you have to keep emphasizing it to get the truth before new generations of people.

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.

h/t: Barry