INTRODUCTION

The point that the thought experiments about the cannibals and “Moral Twin Earth” are meant to illustrate could be made in terms of translation. Suppose that we encounter an unknown group of people in some remote area, and that we initially don't know their language. Under what conditions is it appropriate to translate some of their linguistic expressions with our ethical terms and sentences? According to Richard Hare, the answer does not depend on whether they apply these expressions differently from the way we apply “right,” “wrong,” and so on. Nor does it depend on whether their attributions of those terms are based on different nonmoral considerations. And, according to Terrence Horgan and Mark Timmons, the same holds for the fact that their use of the expressions in question is causally regulated by other properties than those that regulate our use of “right” and “wrong.”

These views about translation pose a threat to moral realism. At least, they pose a threat in so far as they support the claim that we can correctly translate someone's words with our “right,” “good,” and so on, in spite of the fact that we assign different truth conditions to sentences that predicate them. For that claim is incompatible with realism. According to realism, two persons are in genuine moral disagreement only if there is some proposition whose truth they disagree about.