The author of the book is a psychiatrist-psychotherapist and practical psychologist. His book is fully a guide to the prevention of mental illness. The knowledge contained in it helps to find ways to understand oneself and others and, therefore, helps prevent mental breakdowns and nervous crises. The book provides a wealth of knowledge on characterology. It is written in a lively, accessible language, so it will be of interest not only to psychiatrists, psychologists and psychotherapists, for whom it is primarily intended, but also to everyone who would like to learn to understand themselves and others. The book can be recommended as a textbook for universities.