This article brings together the history of the social sciences and the history of social thought in Socialist Romania. It is concerned with the development of ideas about the social beyond collectivism, especially about the relationship between individual and society under socialism, from the early 1960s to the end of the 1970s. The analysis speaks to three major themes in the current historiography of Cold War social science. First, the article investigates the role of disciplinary specialization in the advancement of new ideas about the social in the postwar period. Specifically, it asks how the debate over the relationship between sociology and Marxism-Leninism has challenged ideas about collectivism from Stalinist social science. Second, the article shows how social practice, individual and collective agency, and people's subjectivities became theoretically relevant in the 1960s, and how they were integrated, via empirical sociological research, into the reworked conceptual apparatus of post-Stalinist Marxism-Leninism. This complicates accounts about the role of quantification and theorization in postwar social science by foregrounding the intense reflection on the role of empirical research in sociology under state socialism. Third, the article shows how the relationship between individual and society became a topic of interest across social sciences in the 1960s and 1970s. The Marxist humanist approach to the social, although it never achieved the institutional status of a distinct discipline, adds an important perspective from East Central Europe to the existing historiography of the ‘thinning’ of the social in social sciences and social thought beginning in the 1950s.