This chapter argues that the main arguments for substance dualism can be parodied and transformed either into arguments against substance dualism, or into arguments for the thesis that we are composite physical objects. The upshot of the chapter is that those considerations commonly thought to support substance dualism are indecisive at best, since they can be parodied. The arguments discussed include: modal arguments; an epistemic argument; the argument from the alleged fact that facts regarding personal identity outstrip the physical facts; the argument from phenomenology and intentionality; the argument from the unity of consciousness; Lowe’s argument from unity; and the argument from the problem of the many.

Take any putative ordinary object which is divisible into a finite number of small units and tolerant to the loss of one of them. We can remove these units one at a time, and since our object definitely doesn’t exist when there are zero units, and since we cannot pinpoint which removal brings about this destruction,the Sorites Puzzle threatens common sense. We can rescue ordinary objects from its grip, but since independently motivated linguistic explanations of vagueness depend on there being multiple candidate contents of vague terms, these efforts succeed only if there are multiple candidates that can be meant by ordinary object terms. Thus, many more objects than common sense accepts have to exist. The 'arguments from vagueness' also offer soritical reasons for object proliferation. Problematising the categories composite object and persisting thing (rather than specific object concepts), these show that either there are none of these (except simples) or every candidate for making up one, does. The latter, less revisionary alternative is plenitudinism. I defend Modally Full Plenitude, because it is three-dimensionalist and non-reductivist about de re modality – a distinct persisting object in any region, and for every modal profile satisfied by the matter in that region.