1. The Problem of Personal Identity

2. Questions About Personal Identity
Who Am I?
How Unified Am I?
Do I Persist through Time?

3. Do We Persist through Time?: four theories of identity
Illusion Theory – we do not persist through time
If you believe that the self does persist through time, you might subscribe to one of the following:
Body Theory
Soul Theory
Memory Theory

4. Illusion Theory
There is no self that persists through time – that’s the illusion
We change from one moment to the next and are constantly changing
We all undergo persistent qualitative change
David Hume: we cannot perceive any permanent self
William James – our consciousness is in constant change
Heraclitus: no one steps in the same river twice
Asian religions support this view
For Buddhists there is no self

5. Advantages Live in the moment
Don’t worry about past – stop blaming people for their past actions
Eliminate resentment and hate
Stop worrying about the future

6. Problems for Illusion Theory
Why do we punish people for crimes they have committed in the past?
Our lives are meaningful because of our relationships with others – you would have to understand your love for people in a different way
Should we plan for the future if the person in the future is not identical to who we are now?

7. Body Theory Often referred to as animalism
We persist through time if we have the same numerical body
Even if you are brain –damaged you are still “you”
We are the same if our bodies maintain functional organization (living bodies) – even if we lose a body part, we are still the same
Same body: same person
DNA/fingerprinting is proof of same body

8. Problems for the Body Theory
Should it include ability to think and reason?
Numerical and spiritual body not the same
Will I have the same body in Heaven?
Body switches are logically possible (John Locke)
What about complete amnesia?

9. Soul Theory We persist through time if we have the same soul
Same soul: same person
Life after death is logically possible
Even if body dies, the non-physical soul continues to exist
Religion supports the soul theory

10. Problems for the Soul Theory
If souls are non-visible, how can you know for sure it is the same person?
Souls may disintegrate or change – how can I be sure?
Resurrection – if we never die, we do not need to be resurrected
Reincarnation – born again in another form
Soul is separate from the body
Plato: soul inhabits another body after the body is no longer alive

11. Memory Theory
As long as we have overlapping memories, the same numerical person continues to persist.
As long as my memory is around, I am around
Sense of self connected to memory
John Locke – “as far as this consciousness can be extended backwards to any past action or thought, so far reaches the identity of that person”
Leibniz – our sense of self is connected with our ability to remember the past

12. Problems for the Memory Theory
What if we can’t remember parts of our lives? (inconsistency in the theory) – does that mean we are not ourselves?
Direct (recalled right at the moment) vs. indirect memories (not directly able to recall but remembered at one time – like the name of your high school English teacher back in 1970)
False memories (not caused by actual experiences) vs. genuine memories (memories of experiences that in fact happened)

13. Problems for Memory Theory
Bernard Williams – there is more to us than our memories
Cloning – a copy is only a copy
Is inherited memory causally possible?
Dale Parfit – if you are cloned and then you are killed, does your identity persist in the exact copy of you? If you subscribe to the memory theory, you will have survived even if the survivor is not technically identical to you.

14. Some Important Questions
If you could be cloned into a being with the same body and memory, how could you prove that the clone is not really you?
How are you different from the fetus that was once you? Explain with different identity theories.
What about persistent vegetative state?
What if a criminal gets amnesia, lives a moral life, and is then captured. Is he still guilty?
Is it possible to make any sense of resurrection?

15. Further Reading Locke, John. An Essay Concerning Human Understanding.
Parfit, Derek. Reasons and Persons
Perry, John. A Dialogue on Personal Identity and Immortality
Shoemaker, Sydney and Richard Swinbourne. Personal Identity