The incommensurability of values thesis and its failure as a criticism of utilitarianism

The incommensurability of values thesis is widely regarded as an effective and highly detrimental line of criticism against utilitarianism. The article begins by providing some general background about the development of the incommensurability thesis, as used both in mathematics, in the philosophy of science, and, most importantly, in moral and political philosophy. It then moves on to clarify the alleged importance of the incommensurability of values argument as an objection to utilitarianism and to distinguish two different meanings of that argument. The main part of the article provides an analysis of these two alternative meanings. The claim that a particular scale is either not applicable, or irrelevant, or arbitrary, though perfectly valid, is shown to be misguided as a criticism of utilitarianism. The claim that some options cannot be translated into or associated with particular locations on the relevant scale in a way that would generate positive value relations is shown not to pose any real difficulty to utilitarianism by demonstrating that incomparability of that kind is, as a matter of fact, indistinguishable from the notion of rough equality and that, accordingly, indifference towards the choice between the incomparable competing options is justified.