This argument might be challenged in two different ways. First, one might deny that sentences containing numerical singular terms are (literally) true; one might, for example, endorse a fictionalist account of mathematics (Field 1980). For our purposes, we can sidestep this objection and focus on the other premise of the argument, that extensional sentences containing numerical singular terms, if true, refer to numbers—which is to say, in other words, that such sentences, whether true or not, a