Deep disagreement across moral revolutions

Abstract

Moral revolutions are rightly coming to be recognised as a philosophically interesting and historically important mode of moral change. What is less often acknowledged is that the very characteristics that make a moral change revolutionary pose a fundamental challenge to the possibility of moral progress. This is because moral revolutions are characterised by a diachronic form of deep moral disagreement: moral agents on either side of a moral revolution adopt different standards for assessing the merits of a moral argument, and according to the standards they adopt, agents on neither side of the revolution ought to accept the arguments being put forward by those on the other. This threatens to undermine the progressive status of many of our most celebrated historical examples of moral revolutions: if a moral revolution only looks progressive in light of a change in evaluative standards it itself brought about, then moral progress seems relative to a particular historical perspective; if prior to a moral revolution taking place the moral arguments in its favour fall short of the relevant standards, moral revolutions can never be the outcome of rational argumentation. This apparent relativism and irrationality sits uncomfortably alongside our common-sense intuition that the moral revolutions upon which our contemporary moral worldview rests count as genuine moral progress. In this paper, I deepen currently popular Kuhnian-inspired accounts of moral revolution by incorporating Wittgensteinian ideas from Philosophical Investigations and On Certainty. The result is an original way of thinking about deep moral disagreements, moral revolutions, and moral progress.