Rawlsians argue for principles of justice that apply exclusively to the basic structure of society, but it can seem strange that those who accept these principles should not also regulate their choices by them. Valid moral principles should seemingly identify ideals for both institutions and individuals. What justifies this nonintuitive distinction between institutional and individual principles is not a moral division of labor but Rawls’s dual commitments to conventionalism and constructivism. Conventionalism distinguishes the relevant ideals for evaluating institutions from those (...) for evaluating actions, while constructivism explains why this distinction is morally fundamental. (shrink)