This extra layer promises to solve the problem posed by non-extensional contexts, as illustrated by the example of “cordate” and “renate” in (7) and (8). Our worry was that, since these expressions have the same reference, if meaning just is reference, then it seems that any pair of sentences which differ only in the substitution of these expressions must have the same truth-value. But (7) and (8) are such a pair of sentences, and needn’t have the same truth-value. The proponent of possible wo