A student of the philosophy of social science (a topic he investigated through case studies in "Explaining Technical Change"), Elster strongly argued that social scientific explanations had to be built on top of methodological individualism (the belief that only individuals, not larger entities like "organizations" or "societies", can actually do things) and microfoundations (explaining big societal changes in terms of individual actions). He criticized Marxists and other social scientists for believing in functionalism (the belief that institutions exist because of their effect on society) and instead tried to give Marxism a foundation in game theory (the economic notion that people make choices based on the expected benefits and the choices others are likely to make).