 What about the opaque reading of either (17) or (21), which implies that Daniel knows for a fact that this is a leap year—is that reading available for (18) too? The identity theorist might maintain that this reading is indeed available, and then explain why we tend not to use sentences like (18) in the relevant sense, preferring sentences of the form of (17) or (21), on the basis of the relative technicality of the vocabulary of (18). The idea would be that it is just an accident of language that we prefer either (17) or (21) to (18) where what is in question is the sense that implies that Daniel has propositional knowledge that this is a leap year (is acquainted with that fact as a fact), as opposed to having mere acquaintance, under some mode of presentation or other, with the propositional object which happens to be (the fact) that this is a leap year. And if we ask why we prefer (17) or (21) to