All fields of modern social science, including international political economy (IPE), employ ideal types in the development and evaluation of theory. First identified by MAX WEBER as a heuristic and expository method of special importance to the historical-cultural sciences, ideal types have been variously defined and employed since that initial formulation. Accordingly, there is sharp disagreement about the meaning and use of ideal types, most pronounced between those who follow Weber's lead and the logical empiricists, such as Carl Hempel.