During the neurologist Harold Klawan's lifetime, patients came to him from all over America, exhibiting a huge array of troubles, all of which boiled down to one complaint: something was wrong with their brains. As a sympathetic brain detective, Klawans deduced a great deal from his patients, not only about the immediate causes of their ailments but also about the evolutionary underpinnings of their behaviour. This book contains the richest of his clinical tails. He examines a woman suffering from painful foot and moving toe syndrome, whose case remined him that we were once reptiles with brains at the bases of our spines. He discusses with his friend Oliver Sacks his own experience of knocking a recently broken toe with allowed him to see that, while the brain dulls pain, it also block position sense, so that an accident is likely to occur again to the part of the body that was previously hurt.