  Thus one of the most important consequences of Weber’s methodological individualism is that it puts rational action theory at the core of social-scientific inquiry. This is why subsequent generations of social theorists, under Weber’s influence, sought to bring about the methodological unification of the social sciences by producing what came to be known as a “general theory of action” – one that would broaden the economic model of action in such a way as to incorporate the central action-theoretic insights of (primarily) sociologists, anthropologists, and psychologists. The work of Talcott Parsons in the first half of the century was the most important in this regard, with the unification movement reaching its apogee in the collaborative publication in 1951 of Toward a General Theory of Action, co-edited by Parsons and Edward Shils. Yet shortly thereafter, partly due to problems with the unification program, Parsons abandoned his commitment to both methodological individualism and action theory, adopting a purely systems-theoretic view. This led to an overall lapse in the project of producing a general theory of action, until it was revitalized in 1981 by the publication of Jürgen Habermas’s The Theory of Communicative Action.