Iván Szelényi's Yale course Foundations of Modern Social Theory turns to Émile Durkheim's methodology in The Rules of Sociological Method. Szelényi lays out Durkheim's division of the life sciences into biology, psychology, and sociology, the last concerned with collective representations rather than individual minds. He works through Durkheim's criteria for when a phenomenon counts as a social fact, the discipline required to observe such facts rigorously, and the distinction Durkheim drew between normal and pathological social conditions. The lecture spends real time on causality, showing how Durkheim's early wrestling with correlation and causation still shapes debates in social science about studying society objectively without smuggling in moral judgment. The session opens with a review of final exam questions before moving into the main material, recorded as part of the Open Yale Courses series.