Beyond the Expanding Circle: Towards a Pluralist Account of Moral Progress

Abstract This article criticizes the expanding circle theory of moral progress, the view, associated with Peter Singer and others, that moral progress consists primarily in the gradual extension of moral concern to a wider range of beings. While moral inclusion captures an important dimension of progressive moral change, I argue that the expanding circle framework cannot serve as the dominant theory of moral progress, since it is both internally too coarse and externally too narrow . It is internally too coarse because it conflates the width of the moral circle (which beings receive any moral standing) with its depth (how much weight their interests receive). This distinction, captured by contrasting a Moral Cylinder with a Moral Cone , matters when assessing the standing of beings such as invertebrates or digital minds. And it is externally too narrow because moral circle expansion is, at best, one subtype of moral progress among many. I identify several neglected dimensions: justified circle contraction , proper moralization and demoralization , conceptual refinement , value reprioritization , institutional scaffolding of moral behavior , and anticipatory governance under moral uncertainty. A satisfactory theory of moral progress should integrate all of these.