Born Sigismund Schlomo Freud on this day in what is now the Czech Republic, the founder of psychoanalysis, Sigmund Freud (1856–1939) moved to Vienna at age four.

Inspired by the philosophy of Johann von Goethe, Freud studied medicine and physiology. In 1896, he first used the word “psychoanalysis,” and soon after began his own self-exploration—redefining the inner workings of the mind.

“A man should not strive to eliminate his complexes but to get into accord with them,” he believed. “They are legitimately what directs his conduct in the world.”

Freud taught the world that childhood experiences shape who we are. He believed that “anatomy is destiny.” In 1900, he published The Interpretation of Dreams, the revolutionary book he considered his greatest work.

He introduced the id, ego, and superego—and explained, “The mind is like an iceberg. It floats with one-seventh of its bulk above water.”

His ideas stirred debate. “What progress we are making,” Freud said. “In the Middle Ages they would have burned me. Now they are content with burning my books.”

Still, he believed in love and heart: “In the small matters trust the mind, in the large ones the heart.”