Pluralism and associative life: The groups theory of politics and its primary labels ABSTRACT: This article argues that the enduring lack of consensus on a very basic «unity of analysis » in the social sciences is highly dependent on the socio-political diversification of the associative life. In order to found this historically and theoretical notion, this essay explores the closer relationship between social policy and social sciences from his emergence in the German tradition of the « Cameralists », through its transformations in the late 19th century during the period of « methods controversy » (Methodenstreit), up to the contemporary groups theory as a crucial focus of investigation in sociology and political science. The core proposition in this article is that analytical diversification, topical specialization, and theoretical progress of existing disciplines cover different types of associative life in the field delineated by the pluralist theory « label ».