Abstract

Classic game theory assumed that agents could only reason at the individual level. This is an assumption not only of ontological individualism but also of methodological individualism. But this assumption was unnecessary, a heritage from the previous generations of economists and the strong fear of the communist menace at the time. I will explain the roots of this assumption and its limitations, most specifically, how it faces problems when explaining cooperation. Next, I will show how this assumption slipped into evolutionary theory, through the works of John M. Smith (1982) and Richard Dawkins (2017). Yet, as Peter Kropotkin’s (2009 [1902]) work on mutual aid illustrates, evolutionary theory need not assume individualism. To develop this, I will present a contemporary version of game theory that allows the possibility of collective reasoning. This will allow me to explain why altruism is a form of individual reasoning and why solidarity is a form of collective reasoning. On this reading, solidarity is not reducible to the radical individualism present in neoclassical economics and Dawkins’s evolutionary theory, that is, it is not reducible to reciprocal altruism. As long as we do not maintain the assumption of individualism, game theory and evolutionary theory can provide an account of solidarity.