Identity

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Identity

• Introduction to Philosophy
• Kaufman

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Qualitative vs. Numerical Identity

• x and y are qualitatively identical when they are
  exactly similar.
• The five UConn Basketball players in the middle
  are wearing the same jersey, i.e. qualitatively
  identical jerseys. But the jerseys are not
  numerically identical.

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x and y are numerically identical when they are
one and the same Thing. Numerical identity is
what we express with the equals sign

• Lola Brian
• are wearing the same
• shirt, i.e. numerically
• the same, numerically
• identical
• Examples
• 224
• Samuel Clemens Mark Twain

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We will only be concerned with numerical identity

• In particular, we will be concerned with
  identity over time or persistence.
• In virtue of what is something at time t
  numerically identical to something at some later
  or earlier time t?
• Why is it true (if it is true) that I am the same
  person now as I was a year ago?
• Why is it true that the house I own is the same
  house previously owned by Sean and Stacy?
• Or that the painting I bought is the same
  painting as the one painted by Klee?

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Early Nolte
An especially interesting case Personal Identity
Later Nolte
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Why should we care about personal identity?

• Moral Responsibility
• You cant be blameworthy or praiseworthy for
  something done unless you are the same person as
  the one who performed the action.
• Punishment and reward depend in a crucial way on
  personal identity.

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2. The Afterlife

• An overwhelming majority of Americans believe
  that we will exist in some sort of afterlife,
  e.g. heaven, hell, etc.
• But the expectation of existence in an afterlife
  is only significant or relevant if we exist in
  the afterlife. That is, the same person I am now
  exists in the afterlife in the future, and the
  same person you are now exists in the afterlife.

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A Famous Puzzle About IdentityThe Ship of
Theseus (slightly modified)

• Basic Story Theseus owns a ship named The
  Original.
• The Original is composed of a collection of wood
  planks.

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One day, Theseus inherits some money, but he
only gets a small amount each month.

• He uses the money to fix up The Original, but
  because he only gets a little money each month,
  he is only able to replace one plank every month.
• Theseus takes away one plank from The Original
  and places a new plank in its place.

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Theseus replaces one plank a month for 20
years. On March 15 2025, he has this ship, which
he decides to call Shiny

• 
  Shiny

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The Question Is The Original the same ship as
Shiny?

• Sure, they look very different, but so do Early
  Nolte and Later Nolte.
• Sure, they are composed of different matter, but
  so are Early Nolte and Later Nolte.
• Sure, they are different in all sorts of ways,
  but so are Early Nolte and Later Nolte.
• But Early Nolte is the same person as Later
  Nolte. Why wouldnt we think that
• The Original Shiny
• ?

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A good reason to think that The Original Shiny

• Consider this principle
• The Gradual Replacement Principle
• Gradual replacement (or loss or gain) of one
  small part of x does not result in something
  numerically distinct from x.

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So, the picture looks like this

• t1 t2
  t3 .tn
• The Original
  
  Shiny
• All Theseus has done is (gradually) replace one
  plank of The Original (one a month).
• If the Gradual Replacement Principle is right,
  then at t2, the ship with one new plank is
  identical to The Original.
• The Original the ship at t2

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And if the Gradual Replacement Principle is
right, then

• The ship at t2 the ship at t3
• And so on
• The ship at t67 the ship at t68
• But identity is transitive
• If a b and b c, then a c
• So, by transitivity
• The Original Shiny

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Now imagine this version

• I have always coveted The Original. Theseus wants
  to get rid of The Original, but he is very lazy.
  Every month, he removes a plank and throws it in
  a dumpster. Over the years, I have gathered the
  old planks from the dumpster, and have put them
  together in the exact arrangement as The
  Original. On March 15 2025, I have a ship, which
  I call Old Man of the Sea

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The Picture

• t1 t2
  t3.tn
• The Original
  Old Man
• In this version, it seems that
• The Original Old Man
• Why?

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It seems that a things parts play a crucial role
in its identity. Consider the following principle

• Same Parts Principle
• If x and y have all and only the
• same parts, then x y.
• Therefore,
• The Original Old Man

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Now consider the following version

• Theseus replaces one plank a month on The
  Original and puts the old planks in the dumpster.
  And I gather the old planks and put them together
  in the exact arrangement as The Original.

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The Picture
Shiny

• t1 t2
  t3.tn
• The Original
  Old Man
• 
  
• 
  

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What about this version?

• What Theseus does is just what he does in the
  first version. So it seems that
• The Original Shiny
• But I do exactly what I do in the second story.
  So it seems that
• The Original Old Man
• But a feature of identity is
• If a b and a c, then b c
• Therefore,
• Shiny Old Man!!!

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But that cant be right because Shiny is docked
in Greece, and Old Man is cruising in Australia.
Obviously,

• Shiny ? Old Man
• So, we have a contradiction
• Shiny ? Old Man
• and
• Shiny Old Man

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Clearly something weird is going on.

• Our intuitions tell us both that the Gradual
  Replacement Principle is true and the Same Parts
  Principle is true. But accepting both leads to
  the contradiction above.

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Some Suggestions

• The Same Parts Principle is False.
• Instead of putting the old planks together, I
  store them in stacks in a lumber yard
• The stacks and The Original have all and only the
  same parts, but it seems obvious that
• The Original ? Stacks

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Instead of putting the old planks together in the
exact arrangement as the The Original, I use them
to build a summer home, which I call Graceland
West

• Graceland West
• If the Same Parts Principle is true, then
• The Original Graceland West
• Could that possibly be true? (Answer No)

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(2) Mereological Essentialism

• Mereological Essentialism is the view that a
  thing has its parts essentially so any change of
  parts results in a numerically distinct thing.
• This view simply rejects the Gradual Replacement
  Principle.
• On this view, neither Shiny nor any of the
  in-between ships are identical to The Original.
• The Original ceases to exist when one plank (or
  atom!) is lost/gained/replaced.

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Perhaps The Original Old Man

• But 2 things would need to be true
• Old Man has all and only the same parts as The
  Original there cannot even be any new atoms,
  leptons, bosons, etc. (Unlikely!)
• It is possible for things like ships to have a
  gappy existence i.e. they can exist for a
  while, then cease to exist, then resume existing
  again. (controversial)

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Main problem with Mereological Essentialism

• Nothing (or almost nothing) could exist for any
  longer than an instant. That seems wrong. Right?
• It wouldnt matter whether the ship was torn into
  a billion pieces at t or merely had one subatomic
  particle removed at t In both cases the ship
  ceases to exist. ?!?!

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(3) There are no such things as ships (well look
at this later, but this seems like a drastic
suggestion)

• (4) A thing like a ship can persist through
  gradual changes in parts, but not too much
  change.
• Problem How much gradual change of parts is too
  much? Does The Original cease to exist when its
  67th plank is replaced? Why not its 66th or 68th?
  What is special about plank 67??
• Another problem We commonly think that certain
  material things can (and do!) persist through
  gradual replacement of all of their parts. (e.g.,
  trees, human bodies, etc.)

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Personal Identity

• Long time ago
  Roughly the present

Henry Rollins
ME
Me
Henry Rollins
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First, what are persons?

• Here is what the great 17th-century English
  philosopher, John Locke, (1632-1704) thinks
• A person is a thinking intelligent being, that
  has reason and reflection, and can consider
  itself as itself, the same thinking thing, in
  different times and places which it does only by
  that consciousness which is inseparable from
  thinking, and, as it seems to me, essential to
  it it being impossible for any one to perceive
  without perceiving that he does perceive. When we
  see, hear, smell, taste, feel, meditate, or will
  anything, we know that we do so. Thus it is
  always as to our present sensations and
  perceptions and by this every one is to himself
  that which he calls self. (Essay concerning
  Human Understanding 2.27.9)

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Some appealing things about Lockes account of
persons

• Allows for possibility of non-human persons

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(2) Allows for possibility of humans that are not
persons

• For example, fetuses, infants, the severely
  retarded, etc.
• Professor Barnett

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Why what I have just said is not totally
offensive

• One of the most important aspects of being a
  person is bearing moral responsibility for ones
  actions. There is no question that fetuses,
  infants, and the severely retarded are human
  beings (i.e. members of the species homo sapiens
  sapiens), but because they are not individuals
  with moral responsibility (or at least not full
  responsibility), they are not persons in the
  relevant sense.

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It would be inappropriate (and just false) to say
Sophie, you are a bad, morally blameworthy dog
for tackling that much weaker, less glorious dog.

• Some individuals are not morally responsible for
  their actions, and so they are not persons in our
  sense.

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In virtue of what does a person persist over time?

• That is, what are the Persistence Conditions for
  persons?
• The Persistence Conditions for persons are
  whatever replaces C to make the following true
• x at t1 is the same person as y at t2 if and only
  if C
• Figuring out what C is will give us our theory of
  personal identity.

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The Same-Body Theory

• x at t1is the same person as y at t2 if and only
  if x at t1 has the same body as y at t2.
• A reason to think this is right
• We constantly make true and justified judgments
  about personal identity based on the fact that we
  are presented with the same body.
• When we are presented with the same body, it
  seems that we are justified in saying that it is
  the same person.

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A bunch of reasons to think it is wrong

• It is unclear whether the same body is able to
  persist over time. Are these the same bodies?

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(2) The conceivability of person-switching
cases.

• In those cases, the same person can have totally
  different bodies at different times
• (3) No personal afterlife.

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The Same Soul Theory

• x at t1 is the same person as y at t2 if and only
  if x and y have the same soul.
• Positives
• Seems better than the Same Body Theory.
• (b) Accommodates Switching and existence in an
  afterlife.

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Problems with the Same Soul Theory

• Souls are unobservable directly.
• So, either our judgments about a persons
  identity over time are unjustified, or the Same
  Soul Theory is not right.
• Suggestion maybe we can indirectly observe the
  same soul by directly observing bodies, just as
  we indirectly observe the caramel inside the
  intact piece of chocolate by directly observing
  the kind of swirl on the piece of chocolate.

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We can establish a connection between chocolates
that look like this and a caramel filling.

• Same outer appearance, same filling

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Can we similarly establish a correlation between
same body, same soul?

• We establish same outer appearance, same
  filling only by (repeatedly) biting into the
  chocolate and directly observing the filling.
• But, as Weirob (from Perrys Dialogue) says you
  can never, so to speak, bite into my soul.
• So, we cannot establish a correlation between the
  same body and the same soul.
• Therefore, we cannot indirectly observe souls
  either, and we are back at our original problem.

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Lockes objections to the Same Soul Theory

• (1) It is possible for x at t1 to be the same
  person as y at t2 even though x and y have
  different souls.
• The first step is admitting that we know very,
  very little about souls.
• And because I cannot observe your soul, any
  knowledge I could have about souls has to be from
  my own introspection.
• But experience of my own inner life is
  consistent all of the following
• Having one soul for my whole life.
• Having one soul from conception to age 12 and
  another from 12 until the end of my life.
• Having a new soul every second.
• As long as my inner life is transferred to the
  next soul, I could be the same person without
  having the same soul.

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(2) It is possible for x at t1 to have the same
soul as y at t2 even if x and y are not the same
person.

• The admission again souls are mysterious.
• Isnt it possible (or at least as likely as
  whatever soul story you happen to believe) that
  souls are recycled? Perhaps they are emptied of
  their contents (beliefs, desires, etc.) and
  implanted in a new body.
• If this is a possibility, then perhaps Sweet Bob
  Pasnau
• has Hitlers soul.

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If the Same Soul Theory is right, and persons are
morally responsible for their actions, then
Pasnau is blameworthy for Hitlers actions

• But that cant be right, right?
• Therefore, the Same Soul Theory is wrong.

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Some attempts