On one way of talking about a traditional metaethical topic, realists accept that some items appear on the list of what exists in the moral or more broadly normative domain of inquiry. They then divide over whether those items are like what science and experience suggest that all other items on the list of what exists across all domains are like – naturalistic and secular. Reductive naturalists answer this further question affirmatively. Why don’t nonnaturalists? I explore the answer that it’s (...) because normative entities are “just too different” in the sense that they are countably different things. However, I argue that this answer rests on the subtle presupposition that the normative domain doesn’t also contain uncountable entities of the sort that analytic metaphysicians call “stuff”. Taking intuitions of difference seriously points the way to a novel form of metaethical reductive naturalism. The key is to identify the stuff that matters. (shrink)