Abstract

The dissertation is composed of five papers, each of which either deals with a topic in contemporary metaphysics or uses concepts central to contemporary metaphysics as part of the machinery of its argument. Three papers deal with the problem of personal identity. In Hume on Identity: A Defense I argue that Hume, in maintaining that we are always mistaken in ascribing identity to persons, is presenting a fundamental metaphysical problem about identity through change, not trying to analyze the way we talk about change as his contemporary critics charge. I explicate Hume's argument for this alarming conclusion and show it is far more powerful than has been realized. In Parfit on Identity, I criticize recent attempts to reduce persons to series of psychophysical states or stages. I outline a Realist account of persons and argue that identity is what matters in survival. In Memories, Brains, and Identity, I attack John Locke's contention that present identity is a function of present experience. I use counter-instances derived from the literature on split-brains to show that my present experience could have belonged to someone else. A consequence is that the memory criterion of personal identity is essentially incomplete. ;Examples from the literature on personal identity involving fissioning are central to Abortion and The Control of Human Bodies in which I argue that an organism with a strong right to life has a right to the continued use of the biological equipment, the use of which it acquires through the species-typical process of its own creation. A consequence is that if a fetus is a person, he has the right to the continued use of the mother's womb whether she has given it to him or not. ;The papers on Locke and Parfit rely upon the apparatus of possible worlds, which is central to Dreaming and Certainty. If I believe that I am in a world in which I have conclusive evidence that I am awake, and there is a possible world in which I have the same belief and it is false, can I know which is actual on the basis of the evidence I believe is conclusive? I argue that being wide-awake is a self-recognizing state: when I'm not in it I can mistakenly believe that I am in it, but when my belief is true, I know it. I argue that this enables me to recognize that I am not dreaming