Philosopher, writer; born in Madrid, Spain. Immigrating to Boston as a boy, he studied with William James and Josiah Royce at Harvard, where he himself taught philosophy (1889--1912); among his students were T. S. Eliot, Gertrude Stein, and Felix Frankfurter. Hating academic life and American commercialism and Puritanism, he took advantage of a modest inheritance to retire in 1912; he left the U.S.A. to live a solitary life in Oxford, Paris, and after 1925 in Rome. He wrote 18 volumes of philosophy, chief among them The Life of Reason (5 vols. 1905--06) and The Realms of Being (4 vols. 1927--40); his philosophical works are distinguished by their lucid, literary style. In addition he published poetry, literary, and cultural criticism; a novel, The Last Puritan (1935), an unexpected best-seller about Cambridge (Mass.) society; and a three-volume autobiography.