This dissertation examines the changing relationship between social science, economic governance, and political imagination over the past century. It specifically focuses on neoliberal, ordoliberal and neo-Marxist visions of politics and rationality from the interwar period to the recent Eurocrisis. Beginning with the Methodenstreit (or “methodological dispute”) between Gustav von Schmoller and Carl Menger and the subsequent “socialist calculation debate” about markets and planning, the dissertation charts the political and epistemological formation of the Austrian School (e.g., Ludwig von Mises, Friedrich A. von Hayek), the Freiburg School (e.g., Walter Eucken, Wilhelm Röpke, Alexander Rüstow), the Chicago School (e.g., Henry Simons, Milton Friedman, Gary Becker), and the Frankfurt School (e.g., Max Horkheimer, Theodor W. Adorno, Jürgen Habermas). Combining archival research, textual interpretation, and theoretical reflection on these schools, it shows how critical theorists and political economists battled over the future of capitalism and socialism by redefining state, economy, and subjectivity in terms of their (ir)rationality. It also demonstrates the significance of the Austrian, Freiburg, Chicago and Frankfurt Schools’ free appropriation of Max Weber’s binary typologies, including markets vs. planning, formal calculation vs. substantive values, and rationality vs. irrationality. In turn, the dissertation argues that these and related approaches to political and economic rationalization displaced more radical visions of the political as collective struggle and self-rule—with profound implications for the “anti-political” crises of democracy today.