This chapter outlines the theoretical underpinnings for crime prevention programs, to compare and contrast various approaches, and shows the relationship of crime prevention to criminological theory in general and to political policy as it relates to crime control. The classical school was based on the idea of pain and pleasure as basic to human behavior, which is also true of Freudian psychology, behaviorism as found in Pavlov and Skinner, and modern physiological psychology. Such a model is also basic to the crime prevention through environmental design, routine activities, and rational choice models of crime prevention. A theoretical model developed primarily by economists or by sociologists using an economic model has emerged in some years under such titles as an "opportunity model," or a "routine activities model" for crime control. The rational choice model emphasizes the cognitive processes of evaluation, thought, and decision making as they occur at the individual level.