In a popular form described the rare disease of savantism, its reasons, development, the main manifestations are presented. The used literature contains data only of authoritative authors and institutions. Suggest the most acceptable name of a savantism, their characteristics, and the reasons are added treatment, and prophylaxis, further ways of a research are stated. The book contains the explanatory dictionary and the index of literature. In Russian, it is the world's second book about the savants.