A company in the US has patented what it calls a ‘brain fingerprinting technique’, which (to quote from their website) ‘can determine the truth regarding a crime, terrorist activities or terrorist training by detecting information stored in the brain’. Steven Rose cites this claim as an example of the promises and threats – and with them the possibilities, surprises and absurdities – offered by the rapidly evolving brain sciences, in which he has played a professional and distinguished part for over four decades. His aim is to survey the state of play in this domain of science, and to evaluate the promises and threats involved. The result is a lucidly comprehensive and instructive tour d’horizon, full of good sense and striking insights, not a few of them disturbing.

Thirty years ago Rose published what was a comparable book for its time, The Conscious Brain. Some contemporaries regarded its title as hubristic; others thought it paradoxical. Since then the neurosciences have made enormous strides, and indeed have become a veritable industry, in the process spawning at least the possibility,