Economics should include physical aspects of human ecology, as well as the study of cultural, social, and ethical influences on production and consumption. Ecological political economy must be integrative, bridging some of the gaps between the natural and the human sciences; economic propositions should not be made without consideration of the physical, sociological and psychological factors affecting economic activity. For example, analysis of the market for automobiles must include consideration of many issues, including the efficiency of the internal combustion engine, petroleum geology, the social forces leading to urbanization, moral issues such as global inequity and the increase in mortality associated with auto accidents, environmental impacts, the contribution to global warming, and so forth. Several of these issues involve intertemporal and intergenerational issues that are especially hard to fit into a reductionist, chrematistic framework. Otto Neurath realized already in the 1920s (in the context of the debate on the rationality of a socialist economy) that elements of the economy were incommensurable. Neurath’s proposal for a “unified science” that would attempt to clarify relationships such as these, based on contributions from the individual sciences involved, might also be viewed as a form of “universal history.”