The brunt of my claim in this paper is that the notion expressed in the slogan, “incommensurability of values” is misleading at best, pernicious at worst, and that its implications for practical rhetoric—which is to say, arguments when they go to work— are especially unfortunate. The case is straightforward. There is nothing in the original mathematical metaphor or in the developments in philosophy of science that warrants the use of incommensurability as a technical term in ethics. Values are bigger, lumpier (...) things than the term incommensurability prototypically references, and the deployment of the word in philosophy of science also references markedly different issues than it does in the domain of values. Moreover, that domain flat-footedly misappropriates the term for duties it doesn’t serve elsewhere, comparison. Worst of all, the implications of the use of incommensurability as a technical term are to draw attention away from the valueholders, who might well reconcile discrepant values if given the chance, and to direct that attention generally towards reified values, and specifically towards some putative relationship between reified values that precludes reconciliation. (shrink)