 The idea of public reason appears to inhabit a middle ground between two more familiar standards of evaluation in moral and political philosophy. On the one hand, there is consent. Some political philosophers, for example, argue that political legitimacy requires the actual or implied consent of the governed (Otsuka 2003, 89–113; Simmons 1999). On the other hand, there is truth: we can simply ask whether any alleged moral or political principle is true. Public reason does not aim either at consent or truth. Public reason instead requires that our moral or political principles be justifiable to, or reasonably acceptable to, all those persons to whom the principles are meant to apply. An account of public reason must find some way of giving the perspective of individual persons a significant role, without allowing this to collapse into consent: public reason is not simply a way of identifying those principles to which people already consent. But equally, public reason must not define those principles that could be justified to, or be acceptable to, each person as simply those principles that are true. In either case, the idea of public reason would do no independent work.