Development economics, political theory, and ethics long carried on their own scholarly dialogues and investigations with almost no interaction among them. Only in the mid-1990s did this situation begin to change, primarily as a result of the pioneering work of an economist, Amartya Sen, and a philosopher who doubled as a classicist and legal scholar, Martha Nussbaum. Sen's Development as Freedom (1999) and Nussbaum's Women and Human Development (2000) together signaled the emergence of a powerful new paradigm that is commonly known as the "capabilities approach" to development ethics. Key to this approach is the recognition that citizens must have basic "capabilities" provided most crucially through health care and education if they are to function effectively as agents of economic development. Capabilities can be measured in terms of skills and abilities, opportunities and control over resources, and even moral virtues like the virtue of care and concern for others. The essays in this collection extend, criticize, and reformulate the capabilities approach to better understand the importance of power, especially institutional power. In addition to the editors, the contributors are Sabina Alkire, David Barkin, Nigel Dower, Shelley Feldman, Des Gasper, Daniel Little, Asunción Lera St. Clair, A. Allan Schmid, Paul B. Thompson, and Thanh-Dam Truong.