 Anandi Hattiangadi (2018) offers a conceivability argument against the idea that the ethical supervenes with conceptual or metaphysical necessity. The core idea is this. Mutually inconsistent ethical principles each appear to be perfectly conceivable. And in general, conceivability is a good guide to possibility. But if utilitarianism and Kantianism, say, are both true in some possible world otherwise like ours, then the supervenience of the ethical fails.