Moral error theory is the doctrine that our first-order moral commitments are pervaded by systematic error. It has been objected that this makes the error theory itself a position in first-order moral theory that should be judged by the standards of competing first-order moral theories (Here we are thinking, for example, of Dworkin (Philos Public Aff 25(2):87–139, 1996) and Kramer (Moral realism as a moral doctrine. New York: Wiley-Blackwell, 2009). Kramer: “the objectivity of ethics is itself an ethical matter that rests primarily on ethical considerations. It is not something that can adequately be contested or confirmed through non-ethical reasoning” [2009, 1]). This paper shows that error theorists can resist this charge if they adopt a...