Primum non nocere, the Hippocratic dictum, is perhaps the cardinal rule of medicine in general and of medical ethics in particular. This principle has been honoured by most of its practitioners in the long history of medicine. Thus, a book which provides a revisionist history and bunks considerable amounts of accepted or known history needs to be noticed. Medicine has had more error than it has done things right, says the author, David Wooton, Anniversary Professor of History at the University of York, England.