 Facing mandatory retirement in London, and upon being offered an appointment at Harvard, Whitehead moved to the United States in 1924. Given his prior training in mathematics, it was sometimes joked that the first philosophy lectures he ever attended were those he himself delivered in his new role as Professor of Philosophy. As Russell comments, “In England, Whitehead was regarded only as a mathematician, and it was left to America to discover him as a philosopher” (1956: 100).