The Julius Caesar Problem

The Julius Caesar problem concerns cross-categorical identities such as “3 = Julius Caesar”. The problem and its significance to some Fregean projects are explained. The notions of sortal and category are introduced. A neo-Fregean argument to the effect that every object belongs to a unique category is criticized and an alternative, more pragmatic argument to the same effect is developed. The handling of such mixed identity statements often needs conceptual decisions, not just factual discoveries. The conceptual decisions of our ancestors are implicit in our inherited linguistic practices, which have by and large legislated against the overlap of categories, but exceptions to the rule are certainly possible and very likely even actual.