What Is Methodological Individualism? Anatomy of a Controversy

A constitutive version of methodological individualism (MI) derives from the approaches of Menger, Simmel, and Weber. It encompasses two key ideas: causal individualism and interpretive causation rooted in socially constructed meanings, which imply epistemological anti-reductionism. Early proponents such as Mises, Hayek, Popper, and Watkins advanced these principles, though Watkins departed from the constitutive version. Their contributions ignited a decades-long controversy over MI. This analysis explores the MI controversy by examining its foundational premises, proposing a thesis on the factors driving it—mainly involving divergent epistemologies—and testing this thesis through MI definitions in key texts from the 1950s–2010s.