Abstract

Around 750 a.d., new settlements in Chaco Canyon in the Southwest United States began moving toward intensified urban form, monumental architecture, and increased hierarchical social organization that bordered on nation-state authority. But around 1140 a.d., the relatively concentrated populations in Chaco Canyon dispersed over just a few generations. At new destinations emigrants from the canyon did not reinstate the urban intensities and political hierarchies that had dominated there. Four lessons from this history can be drawn. First, the model of social and political coordination that best fits the history of Chaco Canyon is one of escalating and deescalating gift-giving. Models that instead appeal to purely transactional relations, such as contracts, are historically and philosophically inadequate. Second, and more broadly, the real power of any well-functioning, complex, and urbanized society must be a reserve of generalized social trust. This was true then, and remains true today. Third, while environmental pressures play important roles in the formation of foundational urban settlements such as those in Chaco Canyon, we should be careful not to explain too much by them. As then, our own environmental challenges call upon us to nurture political arrangements, especially in our cities, that can address environmental constraints and challenges. Except perhaps when circumstances become impossibly dire, we should treat environmental constraints as the boundaries into which we must fit ourselves through political means. Finally, philosophers should investigate developments in historical urban settlements. Such cases are indispensable for understanding human cooperation, forms of social authority, and environmental decision making.