The aim of this article is to highlight the baleful consequences of positivism in contemporary political science. The author focuses on Gary King, Robert Keohane, and Sidney Verba's Designing Social Inquirybecause it clearly and consistently articulates positivist commitments that tacitly and so often inconsistently, animate much work in the discipline. The author first establishes the positivist commitments that animate King, Keohane, and Verba's argument and then shows that precisely because of those commitments, their theory of inquiry generates two highly regrettable consequences: It hinders our ability to make sense of successful quantitative analysis generally and of causal explanation in particular. More diffusely, but no less important given King, Keohane, andVerba's practical aims, their theory of inquiry is self-defeating in its efforts to impart intellectual unity to the discipline of political science.