  Increasingly, naturalism and the lyrical cry of human imagination became the focal points of Santayana’s life and thought. Pragmatism, as developed by Peirce and James, was an undercurrent in his naturalism, particularly as an approach to how we ascertain knowledge, but there are aspects of his naturalism more aligned with European and Greek thought that presage developments in the late twentieth century. His naturalism had its historical roots primarily in Aristotle and Spinoza and its contemporary background in James’s pragmatism and Royce’s idealism. His focus on and celebration of creative imagination in all human endeavors (particularly in art, philosophy, religion, literature, and science) is one of Santayana’s major contributions to American thought. This focus, along with his Spanish heritage, Catholic upbringing, and European suspicion of American industry, set him apart in the Harvard Yard.