  The debate over non-naturalism is difficult to resolve in part because the issues often hinge on fundamentally different methodological starting points. Advocates of non-naturalism tend to be less concerned with finding a place for value and obligation in the world as revealed by science and more interested in taking our common sense conception of morality as given and seeing what it implicitly presupposes. Non-naturalism’s opponents, by contrast, put a great deal of weight on explaining our moral practices in a way that fits well with a properly scientific view of the world and are happy to reject the presuppositions of common sense if they conflict with that conception. So non-naturalists tend to be more interested than their opponents in respecting our pre-theoretical intuitions about morality and moral judgement. Hence non-naturalists often give substantial weight to the intuitive force of the Open Question Argument. They also are less willing to revise common-sense moral beliefs about particular cases for the sake of aligning those beliefs with some ambitious naturalistic moral theory. It is no coincidence that so-called moral particularists, who deny that morality can adequately be captured by any set of principles linking natural features to moral ones, tend to favor some form of non-naturalism. Naturalists, by contrast, are more likely to emphasize the importance of rejecting beliefs that fit poorly with our best scientific account of reality; if common sense commits us to properties that do not fit well into that account then so much the worse for common sense. Given these deep methodological differences, the only apparent way avoid philosophical stalemate would be to develop an argument for one of the two positions whose plausibility does not depend on the controversial methodological assumptions associated with that position. The best candidate for such an argument considered here might well be the argument that non-naturalists cannot explain supervenience. For the supervenience of the moral on the non-moral seems to fall out of common sense rather than out of our scientific world-view. Since the methodology associated with non-naturalism itself puts great weight on common sense, the argument from supervenience seems like a promising one. At the very least, the argument from supervenience seems uniquely well situated to undermine non-naturalism without begging any central methodological questions.