Returning to the United States in 1933, he taught first at Princeton University (from 1936), moved to the University of California, Berkeley, where he taught from 1945 to 1953, and then returned to Princeton until retiring in 1965. He was elected a Fellow of the American Academy of Arts and Sciences in 1961. He was appointed Bloch Professor at Berkeley (1966–67), and gave the Charles Eliot Norton Lectures at Harvard University in 1968–69. He continued to teach on a part-time basis at the Juilliard School from 1966 until 1983.