This accessible book identifies and evaluates the major competing theories used to guide the goals, policies, and practices of the correctional system. The authors demonstrate that changes in theories can legitimize changing ways of treating and punishing offenders, and they help readers understand how changes in the social and political context of U.S. society influence correctional theory and policy. Designed to motivate readers to become sophisticated consumers of correctional information, the book emphasizes the importance of using evidence-based information to guide decisions rather than relying on nonscientific commonsense or ideology-based beliefs.