Personal Identity

1. Personal Identity

2. Causal efficacy of content

3. Breaking Glass https://www.youtube.com/watch?v=IZD8ffPwXRo

4. Representational Properties An opera singer can (theoretically) break a crystal wine glass with her voice. Suppose she’s singing about love. That doesn’t matter. The physical properties of her voice AND NOT what they mean are causally relevant/ causally efficacious.

5. Mental Representation Later in class we’ll talk lots about mental representation. The general idea is that beliefs like the belief that there is a dog represent things (like the fact that there is a dog).

6. Mental Representation We’d like to think that the representational properties of mental states are causally efficacious: 1. the belief that there is a dog and 2. the belief that all dogs are animals causes 3. the belief that there is an animal because what the first two represent entail what the third belief represents.

7. The Opera Problem But the case looks a lot like the opera singer. If beliefs are realized by brain states, what a brain state can do is determined by its physical properties– not by what it represents!

8. The Transitivity of Causes

9. Causal Theories of Representation Represents

10. Personal identity

11. Derek Parfit • Born in Chengdu 成都, China • Emeritus fellow at All Souls College, Oxford • Author of Reasons and Persons

12. Numerical Identity X and Y are numerically identical when they are literally the same as one another. Numerical identity is the relation every object bears to itself and to nothing else.

13. Other Senses of “Identity” In the social sciences, ‘identity’ can mean “a person's conception and expression of their individuality or group affiliations” (Wikipedia). Here, one and the same numerically identical person might have different “identities” over time– e.g. I might identify as an American and then later as a Hong Konger.

14. The Criterion of Personal Identity The goal in the philosophical study of personal identity is to find the criterion of numerical identity for persons. If I have two people at different times, and they satisfy the criterion, they are the same person; if they don’t satisfy the criterion, they are different.

15. The Criterion of Personal Identity • The Soul Theory: Everyone has an immaterial soul. If you want to know whether X and Y are the same person, you just find out whether they have the same soul. • The Body Theory: X and Y are the same person if and only if they have the same body. • The Memory Theory: X and Y are the same person if X remember’s Y’s experiences, or Y remember’s X’s experiences.

16. Locke on Personal Identity John Locke famously defended the memory theory of personal identity.

17. The Adventures of Little Finger Suppose I cut off your little finger. Now suppose your whole consciousness, your memory of everything you did in the past continues on in the little finger, but a new conscious awareness, with a different memory and no knowledge of what you did in the past comes to exist in the rest of your body. Locke says (a) it’s the little finger who is you and (b) you (little finger) should not be concerned with the actions taken by the body.

18. Vs. The Soul Theory The prince and the cobbler.

19. Socrates Waking vs. Socrates Sleeping “If the same [substance] Socrates waking and sleeping do not partake of the same consciousness, Socrates waking and sleeping is not the same person. And to punish Socrates waking for what sleeping Socrates thought, and waking Socrates was never conscious of, would be no more right than to punish one twin for what his brother-twin did, whereof he knew nothing, because their outsides were so like that they could not be distinguished.”

20. Constitutive Reductionism Parfit argues for a combination of the body/ mental state theory: “A person is an entity that has a body and has thoughts and other experiences.” p. 656 Notice that here, the person is not identical to any of the other things.

21. The Statue and the Lump “If we melt down a bronze statue, we destroy this statue, but we do not destroy this lump of bronze. So, though the statue just consist in the lump of bronze, these cannot be one and the same thing.”

22. “Bare Truth” “Suppose that I already know that several trees are growing together on some hill. I then learn that, because that is true, there is a copse on this hill. That would not be new factual information. I would have merely learnt that a group of trees can be called a ‘copse.’ My only new information is about our language.” p. 657

23. Eliminative Reductionism Buddha has spoken thus: ‘O brethren, actions do exist, and also do their consequences, but the person that acts does not… There exists no Individual, it is only a conventional name given to a set of elements.’ (Cila Mara???)

24. The Teletransporter

25. Argument Against: Replica = Me Suppose the teletransporter malfunctions and fails to destroy my body, even though it succeeds at creating a new one just like it on the planet.

26. The Physical Spectrum The Ship of Theseus: http://www.youtube.com/watch?v=kVAHXiKjgRo

27. The Yes/No Principle The Yes/No Principle maintains that there is always a fact of the matter about whether I exist. We can ask of anyone who does exist: Is this person Michael? And there will either be a Yes answer or a No answer (even if we don’t know what the answer is).

28. Sharp Boundary If we accept the Yes/No Principle, and we accept that my replica is not me, then we will be forced to say that there is a specific point in the Physical Spectrum where the replacement of one cell causes me to cease to exist.

29. No Fact of the Matter Parfit thus rejects the Yes/No Principle. Instead, he says there are possible cases where there is no fact of the matter whether I survived or died. It’s not true that this person is me, and it’s not false either.

30. Personal Identity Purely Linguistic “I may ask [in the TTP case], ‘Will that person be me?’ But that is a misleading way to put my question. It suggests that I don’t know what’s going to happen. When I know these other facts, I should ask, ‘Would it be correct to call that person me?’ That would remind me that, if there’s anything that I don’t know, that is merely a fact about our language.”

31. “Merely Verbal” Questions Sometimes disagreements aren’t disagreements over facts. Some people claim to have been electrocuted. I don’t think they have been, but not because I dispute any of their factual claims.

32. Comparison w/ Consciousness If we find an intelligent alien or a robot, there is a real factual question as to whether it has conscious experiences or not. We may not be able to ever find out, but there is a real fact. Parfit thinks this is not true in the difficult personal identity cases. There’s nothing that we don’t know.