Rawls argues that distributive justice is not about rewarding virtue or moral desert. Instead, it’s about meeting the legitimate expectations that arise once the rules of the game are in place. Once the principles of justice set the terms of social cooperation, people are entitled to the benefits they earn under the rules. But if the tax system requires them to hand over some portion of their income to help the disadvantaged, they can’t complain that this deprives them of something they morally deserve.