PHIL105: The Big Questions

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PHIL105The Big Questions

• Trimester 3 - 2011

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What is Philosophy?

• Using reason rational argument to answer the
  big questions
• The big questions are
• The very important ones
• Hard to answer even when we have all or most of
  the relevant facts

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Introduction to Personal Identity

• PHIL105 T3, 2011 Lecture 1

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Personal Identity

• Who am I?
• What makes me the same person through time?
• What happens to me if Im copied?
• What about people who have their brains chopped
  in half!?!
• Hard questions, even if we have all of the facts

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Terminology

• Numerical identity
• A (literally) unique thing
• Qualitative identity
• Looks, feels, tastes (etc) identical
• Essential properties
• Required for numerical identity
• Accidental properties
• Can change without affecting numerical identity

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Personal Identity the Afterlife

• It can comfort us to think that our loved ones
  live on somehow after death
• But what would that really entail?

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Reincarnation

• You are reborn into a new body after death
• PROBLEM Reincarnations dont seem to be the same
  person

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Resurrection

• You (and your body) come back to life after you
  die
• PROBLEMS
• Need an earth-like place to go to
• If were recreated exactly the same, well just
  die again
• Some of your atoms will be part of other organisms

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Soul Liberation

• When we die, our soul
• leaves our body to live on somewhere else
• PROBLEMS
• What, exactly, is a soul?
• What would your soul be like?
• Is a soul just the hard drive that our memories,
  beliefs, and personality are written on to?
• Is your soul without your body really you?

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Cryogenics

• Being frozen until
• medical advances
• can fix all your
• ailments
• PROBLEMS
• Technological risk
• The brain may be too damaged
• Ice-cream headache

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Cyborgs

• Use technology to keep us alive!
• PROBLEMS
• Will it ever work?
• How will we know?

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Personal Identity the Accident Victim

• Brain damage and amnesia could drastically change
  what a person is like
• But, would it change who they are?

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COMINS

• Continuity of the Mental Is Necessary for Survival

• VERDICT Mr Edwards son has not survived the
  accident
• PROBLEM
• How much and what type of the mental has to
  continue and how must it continue?

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CEBINS

• Continued Existence of the Body Is Necessary for
  Survival
• VERDICT Mr Edwards son has survived the
  accident
• PROBLEM
• This may be necessary, but is it sufficient for a
  person to survive?

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CESINS

• Continued Existence of the Soul Is Necessary for
  Survival
• VERDICT Mr Edwards son has survived the
  accident
• PROBLEM
• If its not the body or the mental what,
  exactly, is the soul again?

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Summary What Makes Us Survive?

• Continuation of mental
• Continuation of body
• Continuation of soul
• A combination
• Has Marthas Mum survived?
• Has Edwards son survived?
• Maybe we dont survive?

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Philosophy ClinicHow to Argue that a Theory is
the Best Theory

• Explain the main theories and their main strength
• Apply the theories to real and whacky examples
• A good theory will give an answer in each case
  (who is the same person?)
• The best theory will give the right answer for a
  good reason in most of the cases
• Good reasons for right answers are generally
  consistent with our reflected-upon intuitions
• But you can also explain why some particular
  intuitions are wrong (and your theory is right)

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The elusive I

• Who here thinks they exist?
• Cogito ergo sum
• Meditation time!! ??
• Lets find ourselves
• Where am I ?!?!

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For Next Time

• Read
• Law, Stephen Brain Transplants, Teleportation
  and the Puzzle of Personal Identity
• Parfit, Derek Divided Minds and the Nature of
  Persons

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More on Personal Identity

• PHIL105 T3, 2011 Lecture 2

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Personal Identity

• We want our theory to provide answers to
  questions like these
• What makes me me?
• What makes me the same person through time?

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Terminology

• Numerical identity
• A (literally) unique thing
• Qualitative identity
• Looks, feels, tastes (etc) identical
• Essential properties
• Required for numerical identity
• Accidental properties
• Can change without affecting numerical identity

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Sci-Fi Disclaimer

• The following whacky thought experiments may
  never be possible in real life
• But, then again, they might!
• Regardless, a good theory of personal identity
  should be able to answer theoretically possible
  as well as actually possible problem cases

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Animal Theory

• In essence, each person is a living animal
• What essentially makes me me through time is that
  I am the very same living creature as the one in
  the photos

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Brain Transplant Case

• A brother and sister have their brains swapped
  while they sleep one night
• Problem for the Animal Theory

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Brain Theory

• In essence, each person is their unique living
  brain
• What essentially makes me me through time is that
  I have the very same brain as the mes in the
  photos

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Brain Recorder Case

• This device re-splices the existing brain bits so
  that a pre-recorded personality (etc) can be
  downloaded into the (same) old brain
• Problem for the Brain Theory

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Stream Theory

• AKA Psychological Continuity Theory
• In essence, each person is (the right kind of)
  continuation of psychological properties
• E.g. What MIGHT essentially makes me me through
  time is that my memories are psychologically
  continuous

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The Reduplication Case

• This device makes perfect copies of anything put
  in cubicle A (in c. B) but the original is
  vaporized
• A new model also makes a duplicate in cubicle C
• Problem for the Stream Theory?

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Modified Stream Theory

• In essence, each person is (the right kind of)
  continuation of psychological properties
• Except when two or more people are
  psychologically continuous (in the right kind of
  way) from one person
• In which case, none of those later people are the
  same person as the original person

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The Duplicator Gun Case

• This device makes a perfect copy of anything shot
  with it but it doesnt destroy the primary target
• Problem for the Modified Stream Theory

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They All Seem Wrong!

• The Animal Theory
• Gets the brain transplant and recorder cases
  wrong
• The Brain theory
• Gets the brain recorder case wrong
• The Stream Theory (AKA the Psychological
  Continuity Theory)
• Gets the reduplication and duplicator gun cases
  wrong
• The Modified Stream Theory
• Gets the duplicator gun cases wrong

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The Teletransporter Case

• You have been teletransporting to work (on a
  very distant planet) for 3 years
• You are at work when you are informed that the
  teletransporter really works like the
  reduplicator (it copies kills you)
• Do you get in and teletransport home? Why? Why
  not?

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Divided Minds and the Nature of Persons

• Derek Parfit
• Split-brain cases tell us something interesting
  about personal identity
• There are no persons in a split-brain case
• But there were no persons before the brain was
  split either

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Why Chop Your Brain in Half?

• Suffers of severe epilepsy had their corpus
  callosum chopped in half to prevent seizures
  spreading across hemispheres
• This means that the two halfs of the brain cannot
  communicate directly with each other
• The resulting body acts as normal in most cases
  and suffers from less debilitating seizures

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The Experiments

• Left hemisphere controls right eye hand (
  speech in right-handers)
• Using a special technique, each hemisphere was
  exposed to a different stimuli
• Each hand responded as though there is a separate
  stream of consciousness in each hemisphere

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How Visual Fields Really Work
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More Info on the Actual Split-Brain Experiments

• A picture is flashed in the left visual field
  (for a right-hander) so fast that the right eye
  cant see it, but the left eye can.
• When asked, the person says they couldnt see the
  picture
• But the locked-in right hemisphere did see it!

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What Goes With What?

• When asked to point to the picture that goes
  with what they see
• Each hand goes for a different picture!

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Does Each Hemisphere Know about the Other One?

• They seem to ignore or be unaware of each other
• Before the op. patients can name objects on both
  sides, but only on one side after the op.

• Interestingly, they dont complain about the loss

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The Ego Theory

• What essentially makes me me through time is that
  all of the mes are the same subject of
  experiences (ego)
• What unites the many experiences I have had in my
  life is that I was the one having them all
• The Cartesian View is an example of this (my ego
  is my soul)

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The Bundle Theory

• We cannot explain our survival through time by
  referring to a person
• Because no person (subject of our experiences)
  exists!
• There are just bundles of mental states
  (experiences) tied together by the causal
  relation of memory (experiencing remembering
  previous experiences)
• We call these bundles lives

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The No Self View

• Buddha was the first bundle theorist
• His No Self View is a type of bundle theory
• People have nominal existence (we sometimes
  talk as if they exist), but only the parts that
  make them up really exist

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Parfit What We Believe Ourselves to Be

• Science tells us that
• There is no evidence for the Ego Theory
• There is evidence for the Bundle Theory
• Most of us believe something like the Ego Theory
  to be true
• Unfortunately, most of us hold false beliefs
  about who we are!
• Me But does science tell us that?

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Replacing Your Cells Case

• A high-tech alien is going to replace some of
  your cells with identical replicas (all at once)
• If it changes 1 of your cells, are you the same
  person?
• What if it changes 100 of your cells?
• There are answers to these qns

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How We are Not What We Believe

• How could we even know if 49 or 50 (or
  whatever) replaced cells is the right place for
  the line?
• It is implausible that a few cells will make the
  difference in the Replacing Your Cells Case
• But that is what our natural beliefs/intuitions
  force us to say!
• Therefore, we should embrace the Bundle Theory

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Bundle Theory Applied

• When applied to all of the cases, the Bundle
  theory rejects the question, what happens to
  you?
• The Bundle Theory can explain what happens, but
  it doesn't refer to persons (because they dont
  really exist)
• If 50 of your cells are replaced, then 50 of
  that bodies cells are replaced
• You dont end or survive because you were never
  there in the first place!
• These cases only raise worries because we dont
  properly understand the nature of persons

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PARFIT Split-Brain Cases and the Ego Theory

• The Ego Theory says that all of the experiences
  in the split-brain case are being had by the one
  ego/person (but in 2 streams)
• The Ego Theory is wrong because it ignores the
  disunity between the two streams of consciousness
• The ego cant just split in two
• Because it is supposed to be the one unique
  persisting essential element of a person

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PARFIT Split-Brain Cases and the Bundle Theory

• On the Bundle Theory, bodies normally have an
  awareness of having several different experiences
  at any one time
• There is no I (an independently existing
  persisting thing) required for the explanation
• In the split-brain case, there are two separate
  states of awareness of experiences
• But neither of those states is a unique,
  independently existing persisting I (they
  dont exist)

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Parfit Split-Brain Cases 1

• While both the Ego Theory and the Bundle Theory
  can explain our normal awareness of experiences
• Only the Bundle Theory provides a good
  explanation for the split-brain cases
• Combined with the lack of scientific evidence for
  the Ego Theory, we should accept the Bundle
  Theory
• Which means that our belief in our persisting
  ego/self/I is false!

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Parfit Split-Brain Cases 2

• When someones brain is divided, two streams of
  consciousness are created
• Neither of the streams is the same person as the
  original
• But, this is just like ordinary survival!
• We are just bundles of mental states tied
  together by remembering what the previous
  experiences were like
• So, with every new experience, who we are changes
  (our old numerical identity dies!)

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For Next Time

• Get ready to discuss
• The Good Life
• Read
• Singer, Peter (ed.) (1994). Excerpts of Ultimate
  Good, in Ethics, pp. 199-205, 211-242, Oxford
  University Press. (Read all except Nozick, pp.
  228-229)