Moral philosopher and professor at New York University. He was the editor-in-chief of MacMillan's Encyclopedia of Philosophy from 1967.
He attended Akademisches Gymnasium and later obtained his B.A. and M.A. at the University of Melbourne.
He signed the Humanist Manifesto.
He had many girlfriends and affairs, but never married or had any children.
He was good friends with the renowned Philosopher Bertrand Russell.