Many moral error theorists reject moral realism on the grounds that moral realism implies the existence of categorical normativity, yet categorical normativity does not exist. Call this the Metaphysical Argument. In response, some moral realists have emphasized a parity between moral normativity and epistemic normativity. They argue that if one kind of normativity is rejected, then both must be rejected. Therefore, one cannot be a moral error theorist without also being an epistemic error theorist. Call this the Parity Argument. In this paper, we address three possible responses to the Parity Argument from moral error theorists: (1) accept the parity but still reject epistemic error theory, (2) reject the parity, (3) accept the parity and defend epistemic error theory. We argue that there are problems with each of these responses, so the Parity Argument stands as a strong counterargument to the Metaphysical Argument. We conclude by drawing some lessons for any future challenges to the Parity Argument.

中文翻译：

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拒绝平价论证的危险

许多道德错误理论家拒绝道德现实主义，理由是道德现实主义意味着绝对规范性的存在，但绝对规范性并不存在。称之为形而上学论证。作为回应，一些道德现实主义者强调了道德规范性和认知规范性之间的对等。他们争辩说，如果一种规范性被拒绝，那么两种规范性都必须被拒绝。因此，一个人如果不是一个认知错误理论家，就不可能是一个道德错误理论家。称此为奇偶性论证。在本文中，我们讨论了道德错误理论家对奇偶论证的三种可能回应：(1) 接受奇偶性但仍然拒绝认知错误理论，(2) 拒绝奇偶性，(3) 接受奇偶性并捍卫认知错误理论。我们认为这些反应中的每一个都存在问题，因此，平价论证是对形而上学论证的有力反驳。最后，我们总结了一些教训，以应对未来对平等论证的任何挑战。