Although his own origins were middle-class, Willard Motley became a naturalistic novelist who specialized in depicting the lives and concerns of proletarian America. In four massive documentary novels Motley explored problems as diverse as the American penal system, corruption in politics, narcotics addiction, and the American exploitation of Mexico. By the time he began his career in the 1940s, naturalism, with its emphasis on the methodical accretion of factual detail and a deterministic philosophy, was out of fashion. Nevertheless, Motley became famous on the strength of his first naturalistic novel, Knock on Any Door (1947), in which he traces the downfall of an Italian-American altar boy who is led by circumstances to become a murderer. Because he dealt with a variety of ethnic groups in addition to blacks, Motley is frequently grouped with other members of what Robert A. Bone has called the "raceless novel" movement of the late...