Theories of Personal Identity

The Problem of Personal Identity

• What makes a human being remain the same individual, over time?  
•  For example, are you the same individual as the baby your mother gave birth to?  Will you continue to exist as a 90 year old?
• What is a human being essentially?
• Criterion of personal identity-- A = B if and only if __________________
• Could you go on existing, as the very same human being, after the death of your body?

The Still Alice problem

• Alice1 makes a video telling Alice2 to kill herself  (movie clip-- :39 - :40  and 1:23 - 1:27)
• "I'm you"....is that true?
• If Alice1 = Alice2, Alice1 is planning a suicide
• If Alice1 =/ Alice2 , then Alice1 is planning a homicide!  
• Is Alice1 planning a suicide or a homicide?

The Soul Theory (Richard Swinburne)

• We are essentially souls (attached to bodies for now)
• You will continue to exist as long as you have the same soul
• Fun fact: you weigh nothing
• Swinburne's "what else?" argument.  You could find yourself (a) in control of another body, or (b) with no body, or (c) with no memory of the past.  So what else could make you you besides an immaterial soul?
• Homework: is he arguing that the soul is immortal?
• p.s.  We talked about Christianity and the afterlife a bit.  More on that topic is here.

Movies Consistent with Soul Theory

• Freaky Friday
• Nine Lives

The Body Theory

• We are essentially bodies (in a comprehensive sense, where the body includes the brain)
• You will continue to exist as long as you have the same body (which is possible despite some degree of change)
• Fun fact: you weigh 150 pounds (or whatever)

The Brain Theory

• We are essentially brains.
• You will continue to exist as long as you have the same brain (which is possible despite some degree of change)
• Fun fact: you weigh about 2 pounds
• Brain transfer argument: if you had an accident and your brain were transferred to a new body, you would survive the accident.

Movies Consistent with the Brain Theory

The Man with Two Brains (1983)

Who is Julia? (1986-made for TV)--start at 10:43

Is this really possible?  Yes!

The Still Alice Problem (in groups, if we have time)

• What does each theory say about whether Alice1=Alice2?
• Which of these three theories is most plausible?
• What's the bottom line (on the theory of personal identity you prefer): is Alice1 plotting a suicide or a homicide?
• What do you really think it is, suicide or homicide?