The rhetoric of Principia Ethica, as of not a few philosophy books, is that of the clean break. Moore claims that the vast majority of previous writing on ethics has been misguided and that an entirely new start is needed. In its time, however, the book’s claims to novelty were widely disputed. Reviews in Mind, Ethics, and The Journal of Philosophy applauded the clarity of Moore’s criticisms of Mill, Spencer, and others, but said they were “not altogether original,” had for the most part “already been brought out by other critics,” and were even “the standard criticisms.”1 To the Mind reviewer, “The book indicates throughout how strongly the author has been affected by Sidgwick’s views.”2 Hastings Rashdall rejected as historically inaccurate Moore’s claim that only Sidgwick before him had recognized that “good” is indefinable: “To say nothing of writers who (like Mr. Moore and myself) learned the doctrine largely from Sidgwick, I should contend that it was taught with sufficient distinctness by Plato ..., Aristotle, and a host of other writers who have studied in their school.”3 Rashdall also described Moore’s principle of organic unities as just “a new and striking way of stating a very old truth.”4 Some recent commentators have taken a similar line. Bernard Williams has said that much of Principia Ethica comes from Sidgwick,5 while Thomas Baldwin, discussing the book’s substantive values, has said the principle of organic unities “was expressly stated by Bradley,” while “McTaggart had for some years extolled the value of love, and the value of art is a central theme of romanticism.”6 Nonetheless, for most of the 20th century Principia Ethica was seen as a revolutionary 1 work, which set a new agenda for philosophical ethics. This view was reflected in a series of books published in the 1960s and 1970s, all of which gave histories of recent moral philosophy that began with Moore and saw later developments as a series of reactions to his work.7 And an influential recent article has reiterated the view, saying Principia Ethica “initiated” a controversy in ethics that persists to the present day.8 Like Moore’s contemporaries, I do not find this view persuasive...