Recognized as the head of both the UCLA and Harvard philosophy departments during his career.
He obtained his Bachelor's from St. John's College, Annapolis, in 1948.
He was elected as a Fellow of the American Academy of Arts and Sciences in 1968.
His parents were residing in Columbus, Ohio, when he was born.
He was a noted expert on ancient philosophy, philosophy of mind, free will, skepticism, metaphysics, and Ludwig Wittgenstein's work.