Best known for his encyclopedic book Folkways (1906), William Graham Sumner was a founding father of American sociology. He explored the foundations of social history and laws of social change from the perspectives of social Darwinism, classical economics, and scientific positivism. Trained for the ministry at Yale, Sumner gravitated to economics and social science through graduate study in Germany and England. As a sociologist, his teaching and writing pushed American social science to abandon philosophical pursuits and embrace investigation of empirical facts. According to his contemporary, Robert E. Park, "the effect of his researches was to lay a foundation for more realistic, more objective, and more systemic studies in the field of human nature and society than had existed up until that time."

William's parents emphasized the value of sobriety, self-reliance, and personal responsibility. This childhood emphasis later led him to embrace classical economic doctrine, including laissez-fare policies of...