1863-1952. Spanish-born US philosopher and critic. He developed his philosophy based on naturalism and taught that everything has a natural basis. Born in Madrid, Santayana grew up in Spain and the US and graduated from Harvard University. He taught at Harvard 1889-1912. His books include The Life of Reason 1905-06, Skepticism and Animal Faith 1923, The Realm of Truth 1937, Background of My Life 1945; volumes of poetry; and the best-selling novel The Last Puritan 1935.