Why did Economics, in its formative phase, have so much input from medically educated writers? The innovations that physicians brought to their economic discourse played a key role in shaping the future of the discipline, and this volume draws together the work of leading international academics to address this fascinating topic. Six doctor-economists are discussed in detail: Petty, Locke, Barbon, Mandeville, Quesnay and Juglar. The central chapters each examine an individual writer, discussing the available details of medical education and practice, economic contributions and possible links between the two. Peter Groenwegen himself provides a contextual introduction and concluding overview, drawing together the disparate findings to suggest which medical topics were the most inspirational for subsequent economies. This ground-breaking study will prove essential reading for historians of economic thought, and will also interest medical historians, general historians and philosophers.