Abstract

Raimo Tuomela has observed that collective and joint activities typically require ‘mutual belief,’ that is, beliefs about others’ beliefs. For example, in order to lift a heavy table together, you and I must believe that the other has the belief that we are to lift the table in a certain way. Different types of collective and joint activities (e.g. actions performed by small ad-hoc groups and actions performed by large, complex hierarchical organizations) seem to require different kinds of ‘mutual belief,’ and thus get different analyses. In this chapter, I argue that we can bring these analyses under one explanatory strategy. This provides a level of unity that is unusual in theories of collective and joint activity.