He started Princeton graduate school in philosophy, a year after I started in physics, but he, too, soon switched to math. He was a bit younger than I and had served a year and a half in the U.S. Army in Europe after the war, where he had a clerical position in which he learned to type at incredible speed, an ability which served him well in his later book writing. He had many interests and talents. I think his undergraduate degree from Caltech was in physics. He knew a lot of history and he played the piano brilliantly.