Many political and moral theorists believe conceptual arguments about the nature of liberty, authority or power cannot be resolved independently of background normative theories. When this view is combined with the assumption that normative disputes are in some sense irresolvable—because, for example, reason fails us here—we have a partial account of the significance of controversy in moral and political argument. Controversy is significant because it is a manifestation of a deeper truth about reason and value. By contrast many would deny that controversy over such matters tells us anything important—it tells us merely what we already know, that disputants are stupid, self interested, in the thrall of an ideology, or informationally deprived.