William Isaac Thomas was a main contributor to the Chicago School of sociological thought, which is at the root of American sociology. He is recognized, along with Talcott Parsons and George Mead, as a founder of symbolic interactionism. Thomas, along with co-author Florian Znaniecki, published The Polish Peasant in Europe and America in 1918, a five-volume tome that was probably his most famous work. The Polish Peasant examines how immigrants adjusted to a new culture and what social factors affected the process. Thomas refused to see people as completely controlled by external social forces. While external controls provided the actor with a range of socially structured choices, the influence of these was important only to the extent that they were subjectively experienced. His concept of attitude as a predisposition of an individual to act in relation to social values, rather than as a purely psychical state, formed the rudiments...