This chapter gives an introduction to the debate between resourcists and capabilitarians on the best metric for interpersonal comparisons of ‘advantage’. It starts by identifying a number of factors that complicate the debate and should be kept in mind while reading this body of literature. The remainder of the chapter zooms in on the philosophical literature about justice, addressing two main topics. The first is the existence of immense human diversity, which resourcists like Rawls and Pogge insufficiently acknowledge and address according to capabilitarians. The second topic is neutrality towards the good life, a value which capabilitarians like Nussbaum fail to respect according to resourcists. In the course of the chapter, several theoretical distinctions are identified that underlie the debate: chance versus choice, natural versus social causes, ideal versus non-ideal theories of justice and distributive justice versus justice as recognition. The difference between resourcists and capabilitarians, so it is concluded, is as much a difference in how they frame the debate about justice as a difference in the evaluative space that they defend.