Theory before method: The case for methodological pluralism in political science

Abstract

Political science is undergoing a pronounced methodological shift toward causal identification and design-based inference, increasingly marginalizing qualitative and observational approaches. We argue that this shift rests on the flawed premise that methods can be ranked in the abstract, independently of the research question and the theories at stake. Drawing on a Popperian understanding of scientific progress, we develop a framework of comparative theory testing in which method choice is derived from the competing theories themselves. When rival theories generate observationally non-equivalent implications—causal, correlational, or descriptive—any form of evidence capable of adjudicating between them has epistemic standing. This grounds methodological pluralism not in a normative appeal for inclusivity, but in the internal logic of rigorous theory testing. We illustrate the framework through canonical examples, propose criteria for evaluating the rigor of comparative theory tests, and show that design-based methods earn their place within—not above—this framework. The result is a unified perspective that preserves our capacity to engage big-picture questions while maintaining the standards of falsifiability and theoretical precision that scientific inquiry requires.