"Three Contributions to the Theory of Sex" by Sigmund Freud is a groundbreaking work published in 1905 that presents his revolutionary theory of human sexuality. Freud examines sexual development across three essays, exploring what he terms sexual aberrations, childhood sexuality, and the transformations of puberty. He argues that sexual urges exist from childhood and that perverse tendencies are universal rather than limited to the abnormal. The work connects sexuality to unconscious forces and neuroses, introducing concepts that would become central to psychoanalytic theory and fundamentally challenge Victorian assumptions about human nature. (This is an automatically generated summary.)