Ludwig Wittgenstein

Ludwig Wittgenstein, son of one of the richest families in Vienna, gave away his fortune, fought in the Austrian army, wrote the Tractatus Logico-Philosophicus in the trenches and a prison camp, and then, believing he had solved philosophy, became a village schoolteacher and a gardener. He returned to Cambridge in 1929 to undo his own book. The Blue Book, dictated to students, and the Philosophical Investigations, published after his death in 1951, replaced the picture theory of meaning with meaning as use, language games and forms of life, and are the most influential philosophy of the century. He told his doctor to tell his friends he had had a wonderful life.