Mentalistic (or Lockean) accounts of personal identity are normally formulated in terms of causal relations between psychological states such as beliefs, memories, and intentions. In this paper we develop an alternative (but still Lockean) account of personal identity, based on phenomenal relations between experiences. We begin by examining a notorious puzzle case due to Bernard Williams, and extract two lessons from it: first, that Williams's puzzle can be defused by distinguishing between the psychological and phenomenal approaches, second, that so far (...) as personal identity is concerned, it is phenomenal rather than psychological continuity that matters. We then consider different ways in which the phenomenal approach may be developed, and respond to a number of objections. That with which the consciousness of this present thinking thing can join itself, makes the same person, and is one self with it, and with nothing else; and so attributes to itself and owns all the actions of that thing, as its own, as far as that consciousness reaches, and no farther; as every one who reflects will perceive. Locke, Essay Concerning Human Understanding [II.xxvii.17]. (shrink)

Those who believe suitably programmed computers could enjoy conscious experience of the sort we enjoy must accept the possibility that their own experience is being generated as part of a computerized simulation. It would be a mistake to dismiss this is just one more radical sceptical possibility: for as Bostrom has recently noted, if advances in computer technology were to continue at close to present rates, there would be a strong probability that we are each living in a computer simulation. (...) The first part of this paper is devoted to broadening the scope of the argument: even if computers cannot sustain consciousness (as many dualists and materialists believe), there may still be a strong likelihood that we are living simulated lives. The implications of this result are the focus of the second part of the paper. The topics discussed include: the Doomsday argument, scepticism, the different modes of virtual life, transcendental idealism, the Problem of Evil, and simulation ethics. (shrink)