With recent developments in psychology, behavioral economics, and even neuroeconomics, the relationship between the human mind and the economy has become a more frequent topic of research within economics. Such research can, as the fields just suggested indicate, take a number of forms. However, one fundamental philosophical issue remains how we move from the minds of distinct choosing individuals to the agreed-upon reality of the social world. How can it be that we all recognize certain social institutions and practices in the absence of explicit collective agreement on their functioning?2