After the publication of his Tractatus Logico-Philosophicus in 1921, Wittgenstein abandoned philosophy. He taught elementary school in a small village in Austria and helped design a house in Vienna for his sister, preserving the philosophical “silence” he thought appropriate both to ethics and to a work of philosophy offering “the final solution of the problems” (TLP, 5). By the mid-1920s, however, he was working on philosophy again, convinced that the Tractatus contained major mistakes. He returned to Cambridge in 1929, where he composed a paper on logical form that he soon repudiated, and, toward year's end, a “Lecture on Ethics.”

In that first year back in Cambridge, Wittgenstein met a young student of philosophy, Maurice O'Connor Drury, who was to become a lifelong friend. Drury was one of those serious, unpretentious people whom Wittgenstein tolerated, sought out, and opened up to. Originally planning on the priesthood, Drury became a physician and a psychiatrist at St. Patrick's Hospital in Dublin. It was to Drury's flat in Dublin that Wittgenstein came when he left Austria in 1938; and again in 1948 after he resigned his Cambridge professorship. Drury was with Wittgenstein when he died in 1951.