A classic work by the founder of Russia’s psychiatric school explores the complex pathways of the human mind. Pyotr Borisovich Gannushkin, a Soviet psychiatrist and founder of his own school, developed the concept of “small psychiatry” and helped advance psychiatric care beyond hospitals. Relying on the “doctrine of resonant insanity,” he studies forms of thinking and will through clinical cases, analyzes the differences between delusion and “resonering,” classifies psychopathy, describing the imagination of pathological liars, the vulnerability of dreamers, the agonizing doubts of psychasthenics, the theatricality of hysterics, the certainty of paranoiacs, and the cruelty of asocial individuals. This book will be useful not only to specialists such as psychiatrists, clinical psychologists, criminologists, students, and scholars, but also to everyone interested in questions of personality, psychopathy, and pathologies. AST Publishing House, 2021.