 Sidgwick, then, faulted Spencer for deceiving himself in thinking that he had successfully made “empirical” utilitarianism more rigorous by making it deductive and therefore “rational.” Rather, Spencer was simply offering just another variety of “empirical” utilitarianism instead. Nevertheless, Spencer’s version of “empirical” utilitarianism was much closer to Sidgwick’s than Sidgwick recognized. Spencer not only shadowed Mill substantively but Sidgwick methodologically.