What does it mean to say that this person at this time is 'the same' as that person at an earlier time? If the brain is damaged or the memory lost, how far does a person's identity continue? In this book two eminent philosophers develop very different approaches to the problem.

I have argued elsewhere that the psychological criterion of personalidentity entails that a person is not an object, but a series ofpsychological events. As this is somewhat counter-intuitive,I consider whether the psychological theorist can argue that a person, while not a substance, exists in a way that is akin to theway that substances exist. I develop ten criteria that such a`quasi-substance' should meet, and I argue that a reasonablecase can be made to show that the psychological theorist's conception of a (...) person meets these criteria. (shrink)