Stanford, born 1957
Robert Sapolsky
Ask why someone did something, and the answer reaches back a second, an hour, a year, a childhood, a womb, a set of genes, a culture and an evolutionary history. At no point in the regress is there room for free will. There is none.
The view
Sapolsky is a neuroendocrinologist and primatologist at Stanford, who spent decades studying stress in wild baboons in Kenya. His book Behave (2017) asked why a person does something by working backwards in time: what happened in the brain a second before; what hormones were doing hours before; how experience shaped the brain over months and years; adolescence, childhood, the womb, genes, culture and evolution.
In Determined: A Science of Life Without Free Will (2023) he drew the conclusion he says follows. We are the sum of biological and environmental luck over which we had no control, and that luck goes all the way down. There is no free will, not even a little. Moral responsibility, in the sense in which people deserve blame and punishment, is unjustified and should be given up.
The argument
Show me a neuron that started a behaviour without being influenced by any prior event, and I will grant you free will. After Sapolsky, Determined (2023)
Sapolsky's challenge is aimed at anyone who says free will exists. Point to the place in the chain where the person stepped in as an independent cause. Every candidate, he argues, turns out to have its own causes, from the neuron's last few milliseconds to the culture its owner was raised in. Step back through the causes of a single act below.
He is not a fatalist about the future. People change, he insists, but they change because something changed them, an experience, an argument, a book, not because they freely chose to. And he thinks that seeing this clearly should make us kinder. Epilepsy was once blamed on witchcraft or sin; now it is treated as an illness. Sapolsky expects that more and more of what we now blame people for will go the same way, and he welcomes it.
Where he meets Dennett
On the science, almost entirely. Dennett had no quarrel with any of the causes in Sapolsky's regress, and agreed that people are products of their genes, upbringing and culture. Both reject any free will that requires an uncaused cause in the brain. Both also want a more humane justice system, with less vengeance and more attention to what works.
Where they part
On what follows. Sapolsky's challenge, find the uncaused neuron, assumes that free will would have to be an uncaused cause. Dennett denied exactly that. Free will is not an event without causes; it is a capacity that some causal systems have and others lack, the capacity to respond to reasons, foresee consequences and change course. A person who can be talked out of a crime is different from one who cannot, and that difference is real however far back you trace the causes. Dennett died in April 2024, a few months after Determined appeared, so he never answered it at length. But his earlier work had addressed its argument: tracing causes back to the Big Bang does not show that nobody is in control now. See also Do we deserve blame?
| Sapolsky | Dennett | |
|---|---|---|
| Is everything fixed by prior causes? | Yes, all the way down; randomness would not help. | Perhaps. Freedom does not depend on the answer. |
| Is free will compatible with determinism? | No. Compatibilism changes the subject. | Yes. Every kind of freedom worth wanting survives determinism. |
| Do we have free will? | No, not even a little. | Yes: an evolved capacity to act for reasons, which comes in degrees. |
| Does anyone deserve blame? | No. Blame and retributive punishment are unjustified. | Yes, within a fair system of rules that free agents have reason to accept. |
Further reading
- Robert M. Sapolsky, Determined: A Science of Life Without Free Will (Penguin Press, 2023).
- Robert M. Sapolsky, Behave: The Biology of Humans at Our Best and Worst (Penguin Press, 2017).
- Robert M. Sapolsky, A Primate's Memoir (Scribner, 2001): his years with the baboons.