The MindBody Problem

1
The Mind-Body Problem

• Zombies and Other Minds

2
David Chalmers For wonderful links visit his site
at http//consc.net/chalmers/
3
(No Transcript)
4
The Problem of Other Minds

• Intuitively, there is a problem
• Intuitively, it cant be settled by empirical
  investigation concerning brain-states or behavior
• The cerebrescope thought-experiment
• Blind sight (a Zombie Within case)
• William James automaton case
• Analogy argument seems weak we only know of
  psychophysical correlation in one case--our own
  because we have

5
Privileged Access to (some) mental states

• We are aware of them non-inferentially while
  others can only infer them from our behavior
• We cant be mistaken about the character of these
  states while others can
• Theyre logically private even of others can
  experience mental states similar to mine they
  cant experience my mental states.
• Theyre like something for us but not for
  others (vide Nagel on what it is like to be a
  bat)

6
St. Marks, Venice

• To my chocolate lab, Ducati, sniffing around the
  neighborhood after the rain is like looking
  around St. Marks is to me. But as a
  visually-oriented human I still cant get what
  its like for him.

7
Brain states dont have these features

• We arent non-inferentially aware of either our
  own brain states of anyone elses
• We can be mistaken about their character
• Theyre public others can observe my brain state
• Having them (it seems) isnt, or neednt be
  like anything for for me

8
The Mind-Body Problem

• Are mental states/events (or properties)
  identical to brain states/events (or properties)?
• If not, what is the relation between them?
• If so, can talk about mental states be reduced
  to talk about brain states? Should it be
  eliminated altogether?
• Are zombies possible? If so, what if anything
  does that possibility show about the answer to
  these questions?

9
Assumption

• Lets assume, for the sake or the argument, there
  there is an external world of objects which are
  mind-independent
• The same problem can be formulated for
  phenomenalists and Berkeleian idealists but for
  simplicity we assume that there a world out there
  beyond the veil of perception

10
Mind-Body and Personal Identity

• The mind-body probem and the problem of personal
  identity, though related should not be conflated
  (John Perry)
• Mind-Body dualists may hold physicalistic
  criteria for personal identity that preclude
  post-mortem survival
• Mind-body physicalists may hold mentalistic
  criteria for personal identity that allow for
  post-mortem survival

11
Dualism
12
Interactionist (Cartesian) Dualism
13
Interactionist Dualism

• Dualism of substances
• Not (overtly) unscientific
• Descartes Modal Argument for Dualism
• 1. It is imaginable that one's mind might exist
  without one's body therefore
• 2. It is conceivable that one's mind might exist
  without one's body therefore
• 3. It is possible one's mind might exist without
  one's body therefore
• 4. One's mind is a different entity from one's
  body.

14
Epiphenomenalism
15
Epiphenomenalism

• Mental states are the smoke from the factory
  (Huxley) or motes of sunlight on the water
  (Santanaya)
• Dualism of events/states, dualism of properties
  of events/states
• Not (overtly) unscientific but
• There are other problems

16
Epiphenomenalism Problems

• Ephiphenomenal states/events are superfluous
• We have no reason to believe that they occur in
  the third-person case
• They cant be the causes of
• Introspective awareness
• Observable behavior

17
Parallelism
18
Dualism The Problem

• Ockhams Razor "entia non sunt multiplicanda
  praeter necessitatem", or "entities should not be
  multiplied beyond necessity
• Dualism(s) may not yield results that contradict
  science or common sense but if theres no good
  reason to believe in non-physical entities,
  states/events or properties then we ought not to
  believe in them!
• Is there any good reason?

19
Physicalism
20
The Type-Token Distinction

• Banana I know how to spell it but I dont know
  where to stop
• Mental states and multiple-realizability
• Functionalism, computers and extrinsic properties

21
Physicalism
22
The Identity Theory

• What makes a mental state the kind of mental
  state it is, is the kind of brain state it is.
• Mental states are the same kind of mental state
  when theyre the same kind of brain state.
• Multiple Realizability objection But what about
  Martians? Or, less radically, Labrador
  Retrievers? Or just different sorts of people, or
  people at different times?

23
Multiple Realizability

• These guys are different from us. They have
  different brains and different brain states. But
  they can feel the same emotions (we think) and be
  in the same mental states as us even when theyre
  not in the same brain states!

24
Anomalous Monism

• Mental states are just brain states each token
  mental state is identical to some token brain
  state
• The same kind of mental state neednt be the same
  kind of brain state a mental state may be
  realized in different ways, just a programs may
  be realized in different hardware.
• But then, what makes two token mental states the
  same kind of mental state???

25
Functionalism

• Functionalism is one answer
• Functionalism what makes something a mental
  state of a particular type does not depend on its
  internal constitution, but rather on the way it
  functions, or the role it plays, in the system of
  which it is a part.

26
(No Transcript)
27
Functionalism

• Mental states (for humans) are realized by brain
  states (but could conceivably be realized by
  states of a computer or a spiritual substance)
• Mental states are the same when theyre the same
  functional state, i.e. when they produce the same
  outputs and inputs.
• Outputs and inputs are both overt behavior and
  transitions to and from other brain states.

28
Problem with Functionalism

• Functionalism works fine for mental states like
  believing 2 2 4 that arent necessarily
  like anything from the inside but
• Qualia pose a problem
• Because, intuitively, even with the same inputs
  and outputs, states may still feel
  different--or not feel at all!

29
Enter the Zombies
30
The Zombie Problem

• (Philosophical) Zombies are duplicates of normal
  humans like us (who have qualia)
• Zombies (by definition) do not have qualia
• So having qualia is one kind of mental state that
  cant be identified with either a physical or
  functional state.

31
Basic Zombie Argument

• Zombies are conceivable.
• Whatever is conceivable is possible.
• So, its possible that any physical or functional
  state whatsoever occur without involving qualia.
• So, there must be something more to feely
  mental states than their physical or functional
  character.
• So, as a account of what all mental states are,
  functionalism and (perhaps) physicalism generally
  fail.

32
Butsome questions

• Are zombies conceivable?
• If so, what kind(s) of zombies are conceivable?
• Behavioral duplicates?
• Functional duplicates?
• Physical duplicates?
• And in what sense, if any, are zombies of these
  sorts possible?

33
Different Kinds of Zombies

• Behavioral Zombies make the same overt movements
  (including utterances) that conscious creatures
  do but may have any internal structure--or none.
• Functional Zombies make same overt movements and
  have same internal organization.
• Physical Zombies identical to conscious
  creatures cell for cell, molecule for molecule
  and atom for atom.

34
Tom Polger asks

• What sorts of zombies are compatible which which
  physicalistic theories of mind
• given which accounts of possibility
• The Basic Question Is it y-ly possible that
  there be two creatures that are x-ly identical to
  one another but differ in that one is conscious
  and the other isnt?

35
Why ask the question in this way

• Because conceivability is a vexed notion and
  prior commitments to theories of mind can color
  our intuitions about whats conceivable
• Because even if we never agree about intuitions
  we want to know what baggage different theories
  of mind carry
• Because the assumption that conceivability
  entails possibility is problematic we want to
  know what kind of possibility, and what different
  kinds of possibility do to the argument.

36
Possibility weakest to strongest

• Logically possible not contradictory
• Metaphysically possible DISPUTED!. Roughly,
  whats possible given the structure of natural
  kinds.
• Naturally possible compatible with all and only
  the actual substances and laws of nature.

37
Zombie Score Card

• Suppose youre a physicalist (of some sort)
  which possibilities are compatible with your view?

38
Dualism is logically possible

• Questions (Q7)-(Q9). Is it logically possible
  that there be two creatures that are
  behaviorally, functionally, or physically
  identical to one another but differ in that one
  is conscious and the other is not?

39
Analytic Behaviorism is false

• Questions (Q1), (Q4), and (Q7). Is it logically,
  metaphysically, or naturally possible that there
  be two creatures that are behaviorally identical
  to one another but differ in that one is
  conscious and the other is not?

40
Physical Duplicates

• Question (Q3). Is it naturally possible that
  there be two creatures that are physically
  identical to one another but differ in that one
  is conscious and the other is not?

41
No naturally possible physical duplicates for
physicalists

• Functionalists are committed to the view that two
  things that are functionally identical are
  identical in consciousness and two things that
  are physically identical are also functionally
  identical.
• For the Identity Theorist mental states are
  identical to physical states, so two things with
  the same physical states necessarily have the
  same mental states.
• An exception to the negative answer to question
  (Q3) might be some sorts of anomalismbut one
  would have to deny any lawful or lawlike
  connection between the two aspects or kinds of
  properties-even a one-way connection.

42
Metaphysical Possibility

• Questions (Q5) and (Q6). Is it metaphysically
  possible that there be two creatures that are
  functionally or physically identical to one
  another but differ in that one is conscious and
  the other is not?

43
Functional Zombies?

• Questions (Q2). Is it naturally possible that
  there be two creatures that are functionally
  identical to one another but differ in that one
  is conscious and the other is not?

44
Whos afraid of functional zombies?

• To show that functionally identical zombies are
  naturally possible I would have to provide either
  an argument for Identity Theory or dualismor an
  argument against functionalism.
• Identity Theory some physical states may produce
  qualia like the stomach produces gastric juices
  while functionally identical states dont.
• Dualism qualitative states arent functional
  states at all but states of a spiritual substance
• Falsity of Functionalism qualitative states
  arent functional states whatever else they are

45
The Moral(s) of the Story

• Philosophy clarifies the problems but doesnt
  (usually) produce uncontroversial solutions.
• The possibility of zombies seems to undermine
  physicalism--but it depends on what we mean by
  possibiity and what we mean by zombies