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 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.

A notorious problem that has recently received increased attention in axiology, normative theory and population ethics is the apparent ubiquity of what can be generally called nondeterminacy. This paper illustrates how nondeterminacy can spawn cyclical rankings. So, accepting that practical reasons can admit of nondeterminacy challenges the widely held idea that ‘better than’ is transitive. As a result, standard approaches to rational choice under nondeterminacy fail to be action-guiding, since in some situations all options are dominated, that is, impermissible according (...) to standard rational choice criteria. (shrink)

This article shows that introducing the positive comparative relation parity only helps one block so‐called “Spectrum Arguments” in order to avoid their unsavoury implications if one specifies parity in a specific way with respect to its persistence. The article illustrates how parity must both admit of persistency and be weakly non‐persistent for parity to block Spectrum Arguments, and identifies some consequences of that discovery for the general debate on Spectrum Arguments, value theory and comparability problems.