  To put the point another way: Assume that causal reference theory is true for moral terms, and assume that different properties causally regulate the use of moral terms in different societies. If both of these assumptions are true, it follows that moral terms refer to different things in different societies. And it does seem, empirically, to be the case that different properties causally regulate the use of moral terms in different societies. Thus, if causal reference theory is true, cross-cultural moral disagreement should be impossible. Just as someone on Twin Earth doesn’t have a word in their language to refer to water—they just refer to something else (XYZ) that they call ‘water’—people in different societies don’t have words for right or wrong—they only have words for something else that they call ‘right’ or ‘wrong.’ To the extent that this is a counter-intuitive implication, this is a problem for causal reference theory. (It is worth noting that some moral relativists have not found this implication to be counter-intuitive at all. Prinz (2007) and Wong (2006) have both defended versions of moral relativism that are grounded entirely in the Cornell realists’ empirical methodology.)