The book by the famous French philosopher Michel Foucault (1926–1984) is devoted to the perception of the phenomenon of madness in European culture of the 17th–19th centuries. Analyzing various forms of experience of madness - the institution of isolation of the insane, legal acts and medical treatises, literary images and folk superstitions, the author examines the formation of modern concepts of "madness" and "mental illness", which stand out from the general idea of "unreason" characteristic of the classical era as violation of social and ethical norms. The book, in a new way, illuminates the origins of the psychological experience of madness in the 20th century: 19th-century positivism, Freudian psychoanalysis, Nietzsche’s philosophy, etc. Of additional interest is the extensive material of art and literature attracted by Foucault (from Erasmus of Rotterdam and Sebastian Brant to the Marquis de Sade, from Bosch to Van Gogh).