Sigmund Freud

Born in Freiberg, Moravia, in 1856 and later working in Vienna, Sigmund Freud trained as a neurologist before developing the method and theory that became psychoanalysis. He explored how unconscious conflict, childhood experience, and repression might shape behavior, and he became one of the most widely discussed thinkers of the modern era.

Freud wrote books that reached far beyond medicine and psychology, including The Interpretation of Dreams, Three Essays on the Theory of Sexuality, Beyond the Pleasure Principle, and Civilization and Its Discontents. Even readers who disagree with him often recognize how deeply his ideas influenced literature, criticism, therapy, and the everyday language people use to describe inner life.

After the Nazi annexation of Austria, Freud left Vienna for London, where he died in 1939. His work has been challenged on scientific grounds and fiercely debated for decades, but his impact on 20th-century thought is still hard to overstate.