Historian and essayist. He was one of the master expositors of the related values of sense experience (using our eyes, ears, and other sense organs to take in every bit of life) and empiricism (relying on observation, including careful self-observation rather than on logic or on authority). His life and work also expressed the value of a life of contemplation rather than action (in contrast to his immediate forebears, who served as U.S. presidents, congressmen and ambassadors); of friendship and private life; of beauty and estheticism; of knowledge and discovery; and of the appreciation of complexity and paradox.