Where to Start with Robert Sapolsky: A Reading Guide
Where to start with Robert Sapolsky — how to approach Determined, his essential argument for determinism and life without free will. A complete reading guide.
By Elena Marsh
Robert Sapolsky (born 1957) is an American neuroendocrinologist and professor at Stanford who has spent his career studying the biology of human and primate behavior. His earlier book Behave: The Biology of Humans at Our Best and Worst (2017) is a comprehensive account of the biological causes of human behavior; Determined: A Science of Life Without Free Will (2023) takes the argument of that book to its logical conclusion. Both are works of synthesis that bring together neuroscience, genetics, developmental biology, and endocrinology to address fundamental questions about what we are and how we act.
Where to Start: Determined (2023)
The essential Sapolsky — and his most important and controversial book. Determined begins where Behave ends: having demonstrated that human behavior is the product of biological, developmental, cultural, and historical causes operating across multiple timescales, Sapolsky now asks the obvious question: if every decision we make is caused by prior factors we did not choose, what happens to free will?
His answer is that free will, in any sense robust enough to ground moral responsibility, does not exist. The argument is cumulative rather than dependent on any single finding. When you make a decision, your brain has already prepared for action before conscious awareness of the choice; the brain state that produces that preparation is the product of hormonal conditions in the previous hour; those hormonal conditions are shaped by your stress history and developmental experiences; those experiences were shaped by your genetic inheritance and early environment; that inheritance and environment trace back before you were born. At no point in this chain did you, as a free agent, introduce anything. The causes are prior all the way down.
The book proceeds by engaging with each of the arguments typically offered against this conclusion. Perhaps quantum indeterminacy at the neural level introduces genuine randomness — and therefore freedom? No, Sapolsky argues: random is not free. Perhaps compatibilism saves the concept — the view that free will just means acting from your own desires and reasons, without external compulsion, which is compatible with those desires and reasons being themselves caused? This might be philosophically coherent, Sapolsky concedes, but it doesn’t justify the emotional, legal, and moral weight that “responsibility” actually carries in our institutions.
The final sections are the most speculative and the most important: what would a justice system look like that took determinism seriously? It would still need to prevent harmful behavior — incapacitation is as valid a reason to imprison as punishment — but retribution, the idea that people deserve to suffer for their choices, becomes incoherent. Rehabilitation and prevention replace desert and punishment as the system’s organising concepts. Sapolsky acknowledges this is a long way from where legal and moral thinking currently sits; his argument is that it is where the evidence points.
Reading Robert Sapolsky
Determined is the essential Sapolsky starting point for the philosophical argument; Behave (2017) provides the scientific foundation and is an outstanding standalone work in its own right.
For the full Robert Sapolsky bibliography, reviews, and biography, visit the Robert Sapolsky author page on Editors Reads.
Affiliate disclosure: Links to Amazon on this page are affiliate links. We earn a small commission at no extra cost to you.
Frequently Asked Questions
Where should I start with Robert Sapolsky?
Determined: A Science of Life Without Free Will (2023) is Sapolsky's most important book — the full argument that free will is an illusion and that every decision we make is the product of biological, developmental, cultural, and environmental causes we did not choose. A comprehensive scientific case for determinism that takes the moral and legal implications seriously. His earlier Behave is the essential companion and provides the scientific foundation.
What is Determined about?
Determined argues that the neuroscience, genetics, endocrinology, developmental biology, and cultural history of human behavior leave no room for the kind of free will that could ground moral responsibility. Every choice is caused by factors — brain states, hormones, childhood experiences, genetic inheritance — that trace back before the person making the choice existed. The book then asks what justice, punishment, and moral life look like in a world that takes this seriously.
Should I read Behave before Determined?
Behave (2017) — Sapolsky's earlier book on the biology of human behavior — provides the scientific foundation that Determined builds on, and reading it first deepens the argument considerably. However, Determined recaps the core biological findings as it proceeds, so it is readable as a standalone. Readers primarily interested in the philosophical and moral argument (rather than the science) can start with Determined; those interested in the underlying biology will get more from reading Behave first.
What should I read after Determined?
After Determined, Daniel Dennett's Freedom Evolves is the leading compatibilist counter-argument — Dennett argues that free will properly understood is compatible with determinism and that Sapolsky is attacking a straw man. Sam Harris's Free Will covers similar ground more briefly from the same general direction as Sapolsky. For the legal implications, Elyn Saks's The Center Cannot Hold addresses the justice system's treatment of mental illness with personal depth.
