The case against free will is easily stated. Actions, we remind ourselves, are material events. All such events seem subject to the laws of nature, wired into causally connected sequences that emerged long before we were born or even thought of. Besides, we rely on a stitched-up physical reality to perform actions and to be confident that they will have their intended consequences. If, say, the laws of mechanics did not govern the interactions between my body and the material world, then I could not have walked upstairs to my study to start writing this review.

The biologist Robert Sapolsky’s witty, erudite, imaginative and deeply humane new book is a comprehensive rehearsal of the argument that free will is an illusion. Sapolsky assembles a vast body of evidence to make the case that ‘all we are is the history of our biology, over which we had no control, and of its interactions with environments, over which we also had no control, creating who we are in the moment’. Our actions are the product of a causal chain reaching back through our adolescence, childhood and foetal experiences to culture and evolution.

For Sapolsky, the brain is the key mediator of our behaviour. He draws widely and authoritatively on research showing how lasting changes in brain structure and function result from experiences and circumstances we have not chosen. But he is careful, indeed scrupulous, in his use of neuroscience. He takes great trouble to expose the irrelevance of the famous experiments, endlessly cited by determinists, of Benjamin Libet, John Dylan-Haynes and others showing that the brain commits to an action before people believe they have taken a decision to act. To focus on what he calls ‘the final three minutes of a movie’ – what happens immediately before we act – is to miss the true sources of our imprisonment, Sapolsky argues. Nevertheless, he believes that brain science explains why some people consistently make wrong decisions. 

Some defenders of free will believe that recently science has created a new space for agency. According to quantum theory, the universe is indeterminate at the level of elementary particles. This, however, should offer little comfort, given that human beings are rather bigger than atoms. Attempts to scale up quantum