A commitment to corrections must not lead us to repudiate the notion of deterrence as a legitimate and often obtainable goal of criminal sanctions. Knowledge about de terrence can provide us with more rational means of crime control, and may well liberate corrections from the heavy burdens of unitary assumptions about deterrence and penal sanctions. The necessary beginning of a sustained explora tion of deterrence is the development of sensitivity to the differences in situation, audience, and goal which account for the great differences noted in the effects of threats on human behavior. A few distinctions basic to deterrence research are suggested by the authors.