 Allan Gibbard has suggested that, for Sidgwick, in refining and systematizing common sense, we transform “unconscious utilitarianism” into “conscious utilitarianism.” We “apply scientific techniques of felicific assessment to further the achievement of the old, unconscious goal” (Gibbard in Miller and Williams, eds., 1982: 72). Spencer’s “liberal” utilitarianism was comparable moral science. Sidgwick, however, aimed simply at “progress in the direction of a closer approximation to a perfectly enlightened Utilitarianism” (Sidgwick, 1907: 455). Spencer, by contrast, had more grandiose aspirations for repairing utilitarianism. Merely moving towards “perfectly enlightened Utilitarianism” was scientifically under ambitious. Fully “enlightened” utilitarianism was conceptually accessible and perhaps even politically practicable. And Spencer had discovered its secret, namely indefeasible moral rights.