The problem of too many mental tokens reconsidered

The Problem of Too Many Thinkers is the result, implied by several “permissive” ontologies, that we spatiotemporally overlap with a number of intrinsically person-like entities. The problem, as usually formulated, leaves open a much-neglected question: do we literally share our mental lives, i.e. each of our mental states, with these person-like entities, or do we instead enjoy mental lives that are qualitatively indistinguishable but numerically distinct from theirs? The latter option raises the worry that there is an additional Problem of Too Many Mental Tokens. This paper argues that there is indeed such a problem, at least in fission cases. In the course of articulating this problem, we will make a number of surprising discoveries about the relationship between personal persistence and the metaphysics of mental entities. We will also see that the Problem of Too Many Mental Tokens has significant epistemological and ethical implications, which will haunt us even once we have addressed the Problem of Too Many Thinkers.