Amartya Sen (b. 1933) is an economist and philosopher whose work in social choice theory, development economics, and moral and political theory has been very influential. This entry focuses on Sen’s discussion of Rawls’s views. These are summarized in Sen’s recent book The Idea of Justice (2009). Sen endorses several key features of Rawls’s theory of justice, including its focus on fairness, its account of objectivity, its characterization of persons as rational and reasonable, its view of liberty as a separate value, its insistence on the importance of procedural fairness in addition to the achievement of certain social and economic outcomes, its particular attention to the plight of the worst off, and its effort to connect freedom with real opportunities (Sen 2009, 63–64).

However, Sen makes several criticisms. The three most important concern the metric of justice (2009, 234–235, 253–254, 261–263), the site of justice (2009, x–xi, 10, 18–27, 67–69, 85), and the aims and structure of theorizing about justice (2009, 9–18, 56–57, 97–102). First, Sen argues that Rawls’s focus on social primary goods is insufficient for measuring and comparing peoples’ quality of life. Specifically, the difference principle’s focus on income and wealth faces a deficit common in “resourcist” views of justice. This is their blindness to the “conversion problem”: given personal heterogeneities, diversities in physical environment, variations in social climate, and differences in relational (cultural) perspectives, different individuals can have quite different abilities to convert income and other primary goods into valuable forms of life.