A science of politics? Theorizing equilibrium in political science, 1920s-1990s

This paper traces the evolution of the concept of equilibrium in political science from the 1920s to the 1990s, arguing that despite apparent methodological ruptures-from behavioralism to rational choice theory-the search for equilibrium represents a consistent theoretical pursuit within the discipline. It identifies three major conceptions of equilibrium: as a balance of power in group theory, as a systemic relationship between variables in systems theory, and as a solution concept in positive political theory and new institutionalism. Through critical engagement with figures such as Bentley, Easton, Riker, Arrow, Downs, and Shepsle, the paper illustrates how equilibrium served not only as an analytical tool but also as a rhetorical device bolstering political science's claim to scientific status. Ultimately, it contends that the persistent invocation of equilibrium-despite challenges like the chaos theorem-reflects both a commitment to model-building and the disciplinary aspiration to mirror the explanatory rigor of economics. This historiographical account contributes to a more nuanced understanding of theoretical continuity within the discipline's evolution.