The prevailing orthodoxy in brain science is that since physical laws govern our physical brains, physical laws therefore govern our behaviour and even our conscious selves. Free will is meaningless, goes the mantra; we live in a ''determined'' world. Not so, argues the renowned neuroscientist Michael S. Gazzaniga as he explains how the mind, ''constrains'' the brain just as cars are constrained by the traffic they create. Writing with what Steven Pinker has called ''his trademark wit and lack of pretension'', Gazzaniga ranges across neuroscience, psychology and ethics to show how incorrect it is to blame our brains for our behaviour. Even given the latest insights into the physical mechanisms of the mind, he explains, we are responsible agents who should be held accountable for our actions, because responsibility is found in how people interact, not in brains. An extraordinary book, combining a light touch with profound implications, ''Who's in Charge?'' is a lasting contribution from one of the leading thinkers of our time.