Just a quick overview of some of vI's points. Very informal. Hopefully not seriously inaccurate!
1. Fifth Argument for Dualism
1. if physicalism is true, then I am a hunk of matter
2. me-at-birth was one hunk of matter m1
3. me-now is a different hunk of matter, m2 # m1
4. me-at-birth # me-now
i.e. physicalism is incompatible with personal identity
if dualism is true, then I am a soul
souls don't change their parts over time (presumably)
so there is no similar problem about personal identity for the dualist
premise 1 is false. I'm not a hunk of matter, I'm a physical organism.
Organisms change their parts over time. So, no problem.
However, according to van Inwagen, physicalism is incompatible with the
psychological continuity account of personal identity.
1. If identity is determined by psychological continuity, then body transfer is possible.
2. If physicalism is true, then I am a physical body.
3. If I am a physical body, then body transfer is not possible.
4. physicalism is incompatible with the psychological continuity criterion.
2. Arguments for Physicalism
Princess Elizabeth's problem
ARGUMENT FROM COMMON SPEECH
"I didn't like the way he was looking at me" etc.
Why does alcohol make it hard to think clearly?
Put me in the matter duplicator. What comes out the other end? (Note: all that gets duplicated is the matter, not any sort of nonphysical substance!)
1. A dead body?
2. A crumpled-to-the-floor, drooling but live body? [vI suggests this is what Descartes should say. That's surely misleading; Descartes doesn't think that animals have nonphysical minds, but they don't lay around drooling. Surely our physical bodies are just as complex as those of, say, monkeys, so D shouldn't think our behavior would be any less sophisticated. I think D would have denied that the duplicate would be capable of language, though.]
3. A zombie? [in the technical philosophical sense. vI doesn't seem to consider this possibility.]
4. A conscious, thinking being.
If the answer is 4, dualism is false.