"Étude Médico-Légale: Psychopathia Sexualis" by R. von Krafft-Ebing is a clinical-forensic study published in 1886. This groundbreaking text examines sexual pathology, detailing various paraphilias with particular focus on male homosexuality and bisexuality. The work coined the terms "sadism" and "masochism" and proposed that most homosexuality stems from degenerative heredity. As one of the earliest psychiatric works on sexuality, it profoundly influenced European forensic psychiatry and remains a significant text in the history of psychopathology.