Rethinking the Dualism of Practical Reason and Impartiality in Ethics

Abstract

Is Sidgwick right in claiming that both egoism and utilitarianism are rational, and that the conflict between them—known as the Dualism of Practical Reason—cannot be resolved at all? I shall advance three interconnected arguments to weaken the reasons in support of egoism, thereby attempting to dissolve the Dualism of Practical Reason in favor of its impartial side. Part I presents the first argument, which concerns the underlying structure of the two conflicting theories. I believe that there is a distinction to be made in understanding precisely what the Dualism is about, but in the common understanding of the Dualism among scholars of Sidgwick, the importance of this distinction has been overlooked. With this distinction in mind, I shall argue that while the impartial theory is supported by an abstract and self-evident intuition, rational egoism is not, which casts doubts on its reliability. Part II is largely a response to a persisting challenge from the rational egoist—the claim that I have a reason to favor my interests just because they are mine; I shall provide what I think of as the most plausible and compelling reading of this claim, informed by Caspar Hare’s egocentric presentism; and I shall confront this challenge by trying to ground genuine normative reasons in values, but I concede that my attempt does not succeed. Part III is built on Katarzyna de Lazari-Radek and Peter Singer’s recent attempt to dissolve the Dualism using evolutionary debunking arguments. I show that my first argument about the structure of the Dualism can strengthen their argument against a line of objection in the literature, making it another set of reasons against egoism. All things considered, I believe that reasons against rational egoism are weighty (though not decisive) and that the Dualism of Practical Reason, though not fully dissolvable, need not lead one to total pessimism about the role of reason in ethics. Despite persisting issues, practical reason nevertheless shows promising signs of finding its unity in an impartial theory.