Many recent attacks on consequentialism and several defenses of pluralism have relied on arguments for the incommensurability of value. Such arguments have, generally, turned on empirical appeals to aspects of our everyday experience of value conflict. My intention, largely, is to bypass these arguments and turn instead to a discussion of the conceptual apparatus needed to make the claim that values are incommensurable. After delineating what it would mean for values to be incommensurable, I give an a priori argument that (...) such is impossible. It is widely accepted that value is conceptually tied to desire. I argue that, more specifically, it is proportional to merited desire strength. This connection gives one a metric of all value if there is any such thing. This metric entails that value is a complete ordering over all states of affairs, or, in other words, that value is commensurable. (shrink)