Abstract
Critics and defenders of Rawls' idea of public reason have tended to neglect the relationship between this idea and his conception of democratic legitimacy. I shall argue that Rawls' idea of public reason can be interpreted in two different ways, and that the two interpretations support two different conceptions of legitimacy. What I call the substantive interpretation of Rawls' idea of public reason demands that it applies not just to the process of democratic decision-making, but that it extends to the substantive justification of democratic decisions. I shall argue against this interpretation and suggest a procedural interpretation instead. On this view, public reason is invoked when it comes to the political justification of the principles that should govern the process of democratic decision-making, but not – at least not directly – in relation to the content of public deliberation.