I explore the problem of using primary goods as the index for determining the least-advantaged members in a society in Rawls's theory of justice. I look at the problems presented to Rawls by Amartya Sen and his capabilities approach. I discuss the solutions to Sen's problems given by Norman Daniels, who argues that primary goods are able to take capabilities into account. Finally, I supplement Daniels, arguing that the parameters Rawls uses to define his theory limit Sen's objection and that primary goods are the appropriate metric of justice in Rawls's theory.