1. Numerical identity: two people are identical if they are one and the same. The idea of "individuality" = indivisibility. Qualitative Identity: Two people are identical if they share same qualities.
Animalism: Sort of "I'm my body." We are embodied, bodies being crucial for our physical interactions. C/E Locke's Tale of the Prince and the Cobbler, Siamese Twins. Also with the phenomenon of "transgender" (the transgender rejects his/her body for a different one, i.e. "I was born in the wrong body" is the claim).
2. Memory Theory of personal Identity.
a- Direct memory, indirect memory (by virtue of this theory, when the senile general remembers being the hero but not the boy, he's indirectly remembering the boy).
b- Real memory, apparent memory (the difference between a memory whose experience I can consciously recall and one I may have created myself).
C/E Circularity in Locke's theory.
3. Psychological Continuity Theory: Real memory, apparent memory, quasi-memory. Pshychological conectedness. Two people are psych-connected in they form part of an overlapping series of persons who are...
4. C/E: Williams’ (Reduplication Argument) Parfit's Teletransporter: Consequences. If Parfit dies, Parfit (the copy) is psych.-continuous with the original and has a similar body (remember that it is not really the same body, i.e., Parfit is only numerically identical to himself). One implication at the end of section 4.2 is that identity IS NOT a necessary condition for survival.
5. Brain Theory. Two people are psych-continuous if their psyches caused and realized in the same brain. C/A: Split Brains, Multiple personality syndrome (see the movie Identity) , Parfit’s Division (in this case Parfit's surviving brothers are psych with Parfit and have similar bodies being that they are twins). The experiment shows that one can be psyhc identical to someone else in the same brain (each brother share Parfit's half-brain hemisphere).
6. Character. Character NOT SELF is what matters for responsibility.
7. What is the SELF? A PROCESS. It means a transformation whereby the self is constantly changing while maintaining certain characteristics. Process is time-dependent in the sense that if we look for the change minute by minute we may not see it at all. Once we let time take its course, we start perceiving the change (as when we don't see a person for 5 years and notice how much she has physically and psychologically changed).
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An interesting summary on Personal Identity here.
On Thought experiments.
What matters for psychological continuity?
