Do we have free will? No

Jerry Coyne ran an article the other day on the question of free will. The occasion was the publication of Robert Sapolsky’s book, Determined: A Science of Life without Free Will. Sapolsky, in turn, was interviewed by Hope Reese in The New York Times. The online title, incidentally, was “Robert Sapolsky doesn’t believe in free will. (But feel free to disagree.)”

Coyne, Sapolsky, and I are what are called “hard determinists”: we think that “all our actions are determined by the laws of physics.”

I do not know what all the fuss is about; any physicist could have told them that. Indeed, I said it myself in a 2001 book on science and religion.

The book was No Sense of Obligation: Science and Religion in an Impersonal Universe. It suffered from two main problems: (1) It was 5 or 10 years ahead of its time, and (2) it was not shrill enough and too sympathetic to religion. I have long ago given up the idea of becoming rich on it, and you may read it here, free.

Back to the point: In that book, I argued that humans were biological creatures and therefore governed by the laws of physics. Those laws are deterministic (we will get back to that in a minute), so everything we do, think, or decide is determined by those laws. We may think we have free will; we certainly have to act as if we have free will; but in fact we have no such thing.

Now before you get your knickers in a twist, none of the foregoing implies, for example, that we should not punish criminals. The pain they may inflict is real, and we may have to separate them from society until (or unless) they reform. I suggest, however, that their lack of free will suggests that we should be rehabilitating rather than punishing criminals. But that discussion is a little off-task here.

When I wrote NSO, I assumed that quantum mechanics was itself purely deterministic and that some day we would discover an underlying, deterministic theory. It simply seemed unreasonable that, for example, an atomic nucleus would decide all on its own to emit an alpha particle, rather than being caused to do so by some external agency. It still seems unreasonable to me, but it may not be right.

Does quantum mechanics then come to our rescue and somehow grant free will? No. First, so many molecules are involved in, say, neurotransmission that their action may be considered completely classical and therefore completely deterministic. Even so, the occasional quantum fluctuation would not so much grant free will as it would make our decisions somewhat random, a condition that I think proponents of free will would not particularly care for.

Quantum randomness may have been critically important to the evolution of the early universe. If we ran the “experiment” again, we might, for all I know, end up with a very different universe, one that does not even include us. That said, quantum randomness has very little effect on our daily lives, unless you count, for example, cancers induced by radioactive decay or cosmic radiation. Thus, as Sapolsky would argue, everything we think, say, and do is wholly and unequivocally determined by our detailed histories (except, as I have noted, for the occasional quantum fluctuation).

I conclude, then, that we have no free will in any sense. I do not understand why some people consider that threatening; it simply is the way it is. We feel as if we have free will, we act as if we have free will, and we are treated as if we have free will. Free will is thus a useful fiction, but in reality it is only a fiction.

I will undoubtedly read Sapolsky’s book when I get a chance. I think, though, that I will end with a complaint, one that I have made before: The Kindle edition of this book, which I may lease but not own, costs $18.99. The hardcover costs $23.28, and the paperback $12.95. Thus, I am expected to spend $6.04 for the convenience of leasing the Kindle edition, rather than owning the paperback edition. I was not going to write this paragraph, but I had no choice.