One of the world's greatest scientists of human behaviour shows that free will does not exist - and challenges us to rethink the very notion of choice, identity, responsibility, justice, morality and how we live together.

'A bravura performance, well worth reading for the pleasure of Sapolsky's deeply informed company' OLIVER BURKEMAN, Observer

'One of the best scientist-writers of our time' OLIVER SACKS

Behind every thought, action and experience there lies a chain of biological and environmental causes, stretching back from the moment a neuron fires to the dawn of our species and beyond. Nowhere in this infinite sequence is there a place where free will could play a role.

Without free will, it makes no more sense to punish people for antisocial behaviour than it does to scold a car for breaking down. It is no one's fault they are poor or overweight or unsuccessful, nor do people deserve praise for their talent or hard work; 'grit' is a myth. This mechanistic view of human behaviour challenges our most powerful instincts, but history suggests that we have already made great strides toward it: where once we saw demonic possession or cowardice, for example, now we diagnose illness or trauma and offer help.

Determined confronts us with our true nature: who and what we are is biology and nothing more. Disturbing and liberating in equal measure, it explores the far-reaching implications for society of accepting this reality. Monumentally difficult as it may be, the reward will be a far more just and humane world.