 If the transworld identity theorist were a Lewisian realist about possible worlds, this notion of existence in a world could be clearly distinguished from the neutral notion of existence according to a world, on the grounds that the existence of Russell in a world would require his complete or partial presence as a part of such a world (cf. Section 1.2 above). But, as Lewis notes, the self-styled champions of ‘transworld identity’ who oppose his counterpart theory are philosophers who repudiate a Lewisian realist conception of what it takes for Russell to exist in more than one possible world. Hence, he argues, there is a question about their entitlement to claim that, according to their theory, Russell exists in other possible worlds in any sense that goes beyond the neutral thesis (compatible with counterpart theory) that Russell exists according to other worlds. Thus Lewis writes (using the 1968 US presidential candidate Hubert Humphrey as his example):