 Although Habermas’s account of discourse ethics has been influential amongst those who favor some version of discursive or deliberative democracy (Bohman 1996; Chambers 1996; Dryzek 1990; Dryzek 2000), its capacity to serve as the basis for public reason is the subject of a number of criticisms. Perhaps most importantly, by grounding public reason in a broader account of truth, validity, and rational argument, public reason becomes tied to a specific and controversial philosophical doctrine. But some proponents of public reason believe its role is to serve as a mechanism of justification amongst persons who reasonably disagree about philosophical and other issues typically embedded in what Rawls calls comprehensive doctrines (Rawls 1996, 13). If one believes the idea of public reason should stand apart from any particular comprehensive doctrine or philosophical theory of truth and rationality, the appeal to the presuppositions of rational discourse will be a problematic basis for public reason (see Rawls 1996, 376–381).