"In the Rawlsian paradigm, such a person is likely to be a northwest European or North American with a certain way of asking and answering questions of this sort, even if deprived of self-knowledge of the more circumstantial kind. The liberalism that predictably results from such a mental experiment has always been vulnerable to the charge that it lacks purchase upon real-world challenges: it neither derives from present circumstances nor responds to past experience. Perhaps this would not matter if the Rawlsian approach to grounding liberal thought were primarily addressed to persons of a liberal predisposition. But that would be pointless. The test of such a theorem is how effective it is at convincing persons not already so disposed. And even then, the question remains of exactly how such liberals should act when dealing with persons and societies that do not correspond to their preferences. On this Rawls is by no means silent, but he is forced to introduce external considerations that cannot be derived from the model itself."