It is intuitive to suppose that the question of whether I persist through a given period will always have a metaphysically substantive ‘yes’ or ‘no’ answer. Derek Parfit challenges this intuition. Given the truth of Reductionism, he argues, identity can be indeterminate. The main argument Parfit marshals in support of this claim employs his Sorites-style Combined Spectrum thought experiment. Despite its influence, there are conspicuous gaps in his argument. Notably, he claims that identity is indeterminate when questions about persistence are (...) ‘empty’. But indeterminacy in Sorites puzzles is traditionally held to result from vagueness – a topic Parfit avoids. Without an account of the relationships between vagueness, indeterminacy, and question-emptiness, his argument remains incomplete. I begin by outlining Parfit’s argument as it stands. I then propose that we can provide the missing details by supplementing Parfit’s treatment of the Combined Spectrum with Sider’s notion of nonsubstantivity. This gives us a clearer understanding of Parfit’s indeterminacy claim, and affords the room to accommodate vagueness in his argument. Once we spell out what this means, however, it becomes clear that a more radical conclusion is justified by Parfit’s reasoning: it is always an empty question whether a person persists. (shrink)

Abstract. Could a person or mind be uploaded—transmitted to a computer or network—and thereby survive bodily death? I argue ‘mind uploading’ is possible only if a mind is an abstract object rather than a concrete particular. Two implications are notable. One, if someone can be uploaded someone can be multiply-instantiated, such that there could be as many instances of a person as copies of a book. Second, mind uploading’s possibility is incompatible with the leading theories of personal identity, insofar as (...) these assume the mind is a concrete particular. Moreover, because David Chalmers (2010; 2012; 2014) defends mind uploading without construing minds as abstract, I show Chalmers’ argument to be unsound. (shrink)