'Populated by a cast as strange as that of the most fantastic fiction ... Dr Sacks shows the awesome powers of our mind and just how delicately balanced they have to be.' -- The Sunday Times 'This book is for everybody who has felt from time to time that certain twinge of self-identity and sensed how easily, at any moment, one might lose it.' -- The Times '... insightful, compassionate and moving ... a masterpiece of clinical writing.' -- The New York Times