The Moral Twin Earth challenge to ethical naturalism threatens to undermine an otherwise promising metaethical view by showing that typical, naturalist‐friendly theories of reference determination predict diverging reference in Twin Earth scenarios, making it difficult to account for substantive moral disagreement. Several theorists have recently invoked David Lewis’s doctrine of reference magnetism as a solution, claiming that a highly elite moral property—a moral “joint in nature”—could secure shared reference between ourselves and our twins on Twin Earth, despite our diverging usages of moral terms. This paper argues that this move has significant methodological implications: namely, it entails that a certain sort of simplicity is truth‐conducive. Consequently, when applied to moral theories, this gives certain views, specifically monist ones like utilitarianism and contractualism, an advantage over their more complicated rivals, forms of pluralism and particularism. Thus, ethical naturalists cannot invoke reference magnetism without a substantial impact on first‐order theorizing.

中文翻译：

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道德双生地球上参考磁性的方法论意义

道德双地球对道德自然主义的挑战有可能破坏威胁，因为它表明典型的，自然主义友好的参考确定理论预测了“双地球”情景中的参考存在差异，从而难以解释实质性的道德分歧。几位理论家最近援引了大卫·刘易斯的参考磁性学说作为解决方案，声称尽管我们对道德的用法不同，但高度精英的道德属性（道德的“自然界”）可以确保我们与我们在双胞胎地球上的双胞胎之间的共享参考。条款。本文认为，此举具有重大的方法论含义：即，它意味着某种简单性是符合事实的。因此，将其应用于道德理论时，可以得出某些观点，特别是诸如功利主义和契约主义之类的一元论者，它比其更复杂的竞争对手，多元主义和特殊主义形式更具优势。因此，伦理博物学家在不影响一阶理论的前提下就不能引用参考磁性。