The major drawback of rational choice theory is not its individualistic approach, which is in fact well suited to explain aggregate outcomes; it is its essentially static, or at best cyclical, character that prevents it from coming to terms with social processes in which not only variables, but in the course of time also parameters and even 'constants' must be considered as changing entities. But this is incompatible with the requirements of formal conceptualization and statistical testing procedures. Nevertheless, in decisive episodes, human beings tend to be 'alert' and 'scheming'; the key notions of rational choice theory are too productive to be ignored by historical sociologists, who do well to incorporate them as intellectual concepts in a pragmatic manner.