A major goal of liberal democracy is to protect key individual rights against the potentially oppressive power of both the state and the majority of citizens. Neither of these forces can impose a particular moral, religious, or ideological doctrine as the basis for public life and must instead accord equal legal respect to all versions of what constitutes the supreme good in life. Pluralism must of course be reasonable to the extent that it cannot tolerate belief systems contrary to the basic maintenance of social order or to the principles of justice as fairness on which social order rests.

This is a concept that Rawls proposed in A Theory of Justice and continued to develop over the course of his career. Its basic premise is that the fairest origin for a society would require none of those responsible for its creation to know what their role in it would be. Otherwise, they would have an interest in making sure that institutions reflected the interests of the group to which they belonged. If a “veil of ignorance” (15) inhibited such knowledge, all would have to assume that they could end up as one of the “least advantaged,” and so everyone would ensure that the social system they designed put the least advantaged in the best possible position.