Sidgwick’s Critique of Deontology: Scrupulous Fairness or Serpent-Windings?

David Phillips (2011) and Thomas Hurka (2014a, 2014b) argue that Sidgwick’s critique of deontology contains three serious flaws. First, it has no force against moderate deontologies composed of prima facie duties rather than unconditional duties. Second, Sidgwick’s preferred principles fail to meet the very criteria by which he rejects deontological principles. Third, Sidgwick’s employment of his key maxim of Rational Benevolence equivocates between all-things-considered and other-things-equal formulations. I defend Sidgwick against all three criticisms. (1) While some of Sidgwick’s arguments apply only to absolute deontology, others apply to moderate versions as well. (2) Although Sidgwick’s preferred principles do not fare perfectly against his criteria, they still fare better than the deontological principles. (3) The suggestion that Sidgwick relies on an all-things-considered formulation of Rational Benevolence is based on a misunderstanding of the structure of his argument. The upshot is that Sidgwick’s overarching line of argument is stronger than recent critics suggest.