Ruth Chang and Joseph Raz have both drawn far-reaching consequences for agency from the phenomenon of incommensurability. After criticizing their arguments, I outline an alternative view: if incommensurability is vagueness, then there are no substantial implications for agency, except perhaps a limited form of naturalistic voluntarism if our reasons are provided by desires.

This paper argues that accepting incommensurability can be a useful step for developing attractive hybrid theories to how to distribute scarce health-related resources. If one provides opportunity for distributive options to be incommensurable with respect to substantive criteria, one can hold on to substantive criteria while also providing room for decision processes to play a significant role. The paper also argues that the strategy of accepting incommensurability is preferable to the strategy of having substantive criteria establish sets of options that (...) are equally, explains why incommensurability gives us reason to go hybrid, and argues that reasons grounded in decision processes have properties that make them appropriate as “tiebreakers” in choice situations characterized by incommensurability. (shrink)

This paper introduces incommensurability, its potential relevance to population-level bioethics, and thecontributions to the special issue. It provides an overview of recent research on incommensurability, outlines somereasons to believe in its possibility and relevance, and presents some problems and opportunities that arise onceone accepts that incommensurability is possible.