Abstract

Is the natural number 3 identical with the Roman emperor Julius Caesar? In Grundlagen Frege raised some peculiar questions of this sort.1 There are two kinds of intuitions regarding such questions. On the one hand, these questions seem not only to be pointless but to be downright meaningless. Regardless of how much arithmetic one studies, no answer to the opening question will be forthcoming. Arithmetic tells us that 3 is the successor of 2 and that it is prime, but not whether it is identical with Caesar. So questions concerning the identity of numbers and people seem not to be provided for. On the other hand, it seems that the opening question must be answered negatively. For numbers are not the sorts of things that can be identical with people. In fact, since the number 3 is an abstract object and Caesar is not, it follows by Leibniz’s law that they are not identical