One of the most influential thinkers of the 20th century, philosopher Ludwig Josef Johann Wittgenstein (1889-1951) was born on this day to a wealthy Viennese family.

"The limits of your language are the limits of your world," he said.

A headstrong perfectionist, Wittgenstein gave away his inheritance and chose to live an austere life of intense academic work. In 1912, he studied mathematical logic at Cambridge with his mentor Bertrand Russell who compared his "passionate, profound, intense, and dominating" student to Pascal and Tolstoy.

"The truth can be spoken only by someone who already lives inside it," Wittgenstein believed.

He wrote his masterpiece Tractatus Logico-Philosophicus (1922) while serving in World War I. The only philosophical work published during his lifetime, Tractatus was written in German and English with short, numbered paragraphs. The book searched for how language expressed meaning and began: "1. The world is everything that is the case..."

In trying to explain the dance between mind and consciousness, his logical theories and philosophy of language shook the world. He wrote, "Whereof one cannot speak, thereof one must be silent."

He further explored the mysteries of the mind with Philosophical Investigations (1953), which linked language to actions and reactions.

"The world of those who are happy is different from the world of those who are not," he said.

More Wittgenstein Quotations

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