One of the more unsatisfying features of the exchange between Jürgen Habermas and John Rawls was the relatively low level of philosophical engagement between the two thinkers. Most striking of all was the lack of interest that Rawls showed for Habermas’s general theoretical project. Some of the reasons for this are biographical and cultural, but there is an important philosophical reason as well. At the very beginning of his response, Rawls classifi ed Habermas’s philosophical project as a comprehensive doctrine. As a result, he did not regard it as a rival theory to his own, or as a construction intended to occupy the same conceptual space; he treated it instead as just another fl avor of Kantianism. “Of the two main differences between Habermas’s position and mine,” he wrote, “the fi rst is that his is comprehensive while mine is an account of the political and it is limited to that.”1 Thus he did not feel the need to address the details of Habermas’s philosophical project, any more than he would any other private comprehensive doctrine.