Over the last 50 years, the community of heterodox economists has expanded, and its publications have proliferated. But its power in departments of economics has waned. Addressing this paradox, this book argues that heterodox economists are defined more by left ideology than by a shared understanding of the nature of orthodox economics and of what should replace it. Heterodox economists cannot agree on what heterodoxy means. This volume applies work on the social nature and institutions of science to help explain the failure of heterodox economics to gain ground. It assesses some strategic options for its future.