 even though they express the same truth function. The distinction between these terms is not erased, as Sher seems to suggest, if we use them as rigid designators for the truth functions they express. (That “Hesperus”, “Phosphorus”, and “the planet I actually saw near the horizon on the morning of November 1, 2004” all rigidly designate Venus does not entail that they have the same meaning.) Thus Sher’s proposal can only be understood as a stipulation that if one of a pair of coreferential rigid designators counts as a logical constant, the other does too. But it is not clear why we should accept this stipulation. It certainly has some counterintuitive consequences: for example, that \(\dq{P \vee \#P}\) is a logical truth, at least when \(\dq{\#}\) is used rigidly (see Gómez-Torrente 2002, 19, and the response in Sher 2003).