One recently central topic of discussion in political philosophy has been concerned with justice at the global level, the level of all humanity; one increasingly popular - and now quite mainstream - approach to this topic has emphasised the concept of human capability. There are many questions that might be asked in a philosophy Thesis, against this backdrop: about the prescriptions the approach would generate when applied to real-world controversies; about its precise relationship to the social sciences; about precisely which capabilities are of normative significance, and for which purposes1 . This Thesis, however, seeks to re-examine the concepts and proposals that are often in the background when academics or practitioners talk about the capabilities and their relevance to global justice, and so aims to set out a renewed framework within which more fine-grained questions might be pursued. As a result, while I shall occasionally touch directly on clearly first-order questions - as when I discuss the appropriate definition of capability in Chapter 2 - most of my work will relate to more abstract issues in methodology and epistemology, defending a capability approach indirectly by placing it as a coherent element within a broader philosophical context.
