Published in 1909, Über psychopathische Minderwertigkeiten is one of Otto Gross’s major psychiatric works and an important document of early psychoanalysis before the field had hardened into later schools. Gross examines the unstable borderland between normal psychology, neurosis, psychopathy, and psychosis, seeking a theory of the intermediate forms then called “psychopathic inferiorities.” Drawing on Freud’s theory of repression and unconscious complexes, Wernicke’s theory of sejunction, Anton’s theory of compensation, and contemporary degeneration theory, Gross develops an account of heredity, acquired psychic disturbance, affective lack of criticism, flattened and narrowed consciousness, disequilibrium, combined psychopathies, periodicity, intolerance, and the social-biological position of abnormal individuals. The book is historically important because it shows Gross still writing as a physician and psychiatrist while already bringing Freudian mechanisms into the heart of clinical psychopathology. It is a dense, strange, and revealing work from the early history of psychiatry, psychoanalysis, criminology, and abnormal psychology.