One of our great behavioral scientists, the bestselling author of Behave, mounts a devastating scientific and philosophical case against free will—an argument with profound consequences

Robert Sapolsky’s Behave, his now classic account of why humans do good and why they do bad, pointed toward an unsettling conclusion: we may not grasp exactly how nature and nurture create the physics and chemistry that cause all human behavior, but that doesn’t mean they don’t exist. In Determined, Sapolsky takes his argument all the way, mounting a brilliant (and in his inimitable way, delightful) full-frontal assault on the pleasant fantasy that there is some separate self who tells our biology what to do.

Determined offers a marvelous synthesis of what we know about consciousness—the tight weave between reason and emotion and between stimulus and response in the moment and over a life. One by one, Sapolsky takes out all the major arguments for free will, cutting a path through the thickets of chaos theory and quantum physics. But as Sapolsky acknowledges, it’s sometimes impossible to uncouple from our zeal to judge people, including ourselves. Determined applies this new understanding to some of our most essential questions around punishment, morality, and living well together. Most of all, Sapolsky argues that while accepting the reality about free will is monumentally difficult, it will make for a much more humane world.