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Mind-Body Problem

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Title: Mind-Body Problem


1
Mind-Body Problem
2
What is the Problem?
  • How exactly are the physical states of human
    bodies related to the mental states of human
    minds?
  • What is the nature of mind?
  • How do minds and bodies interact?

3
Physical Properties
  • Bodies have physical properties. Give a list of
    physical properties.
  • Bodies are subject to the laws of physics.

4
Mental Properties or States
  • Thought experiment Imagine a universe that
    consists only of physical objects and physical
    properties but which lacks minds and mental
    properties. Make a list of those features of the
    world that would vanish if all minds were
    suddenly wiped out.

5
Mental Properties and States
  • Minds allow us to
  • Perceive, smell, and feel the world
  • Feel emotions
  • Have self-awareness
  • Have dreams, hopes, and fantasies
  • Store and retrieve memories
  • Reason about the world
  • Communicate with others

6
What do all mental states have in common?
  • Feel a sharp pain
  • Being convinced about winning lotto
  • Knowing that 224
  • Smelling coffee
  • Seeing a lunar eclipse
  • Dreaming of traveling to France
  • Remembering to buy milk
  • Imagining a perfect vacation
  • Fearing that the war will go on
  • Perceiving a yellow sunflower
  • Thinking that the earth is round
  • Experiencing frustration

7
Public vs Private Propertiesand States
  • Bodies have properties that are public in the
    sense that anyone, in principle, can observe and
    measure them.
  • Minds have properties that are private in the
    sense that they can be experienced only from a
    first-person perspective.

8
Possible solutions to themind-body problem
  • Metaphysical views of reality
  • Materialism only matter exists
  • Dualism both mind and matter exists
  • Idealism only mind exists
  • Possible Solutions
  • Physicalism (or Materialism)
  • (Substance) Dualism
  • Idealism

9
Physicalism
  • Mental states can be completely explained in
    terms of physical states. Physical states are
    more fundamental than mental states.
  • Mental states are ontologically dependent on
    physical states.

10
Ontological Dependence
  • In general, we can say that one entity X
    ontologically depends on another entity Y if X
    cannot exist without Y.

11
Ontological DependenceAre these true or false?
  • Tigers are ontologically dependent on lions.
  • Rainbows are ontologically dependent on water and
    light.
  • Wood is ontologically dependent on trees.
  • Oranges are ontologically dependent on apples.
  • Children are ontologically dependent on their
    parents.
  • Birds are ontologically dependent on dinosaurs.
  • Heat is ontologically dependent on the velocity
    of molecules.

12
Physicalism or Materialism
  • Physicalist theories
  • Behaviorism
  • Identity theory
  • Functionalism
  • Eliminative materialism
  • Property dualism (some versions)

13
(Substance) Dualism
  • Mental states and physical states are equally
    real and ontologically independent.
  • Problem of interaction
  • Descartes Dualistic Interactionism
  • Parallelism
  • Occasionlism
  • Preestablished harmony
  • Epiphenominalism

14
Idealism
  • Mental states are more fundamental than physical
    states.
  • Leibnizs metaphysics Monads

15
Descartes
  • Purpose He wants to find a certain and
    indubitable (beyond doubt) foundation on which to
    build all knowledge.
  • All knowledge must be based on
  • Intuition The mind can grasp clear and distinct
    ideas with certainty.
  • Deduction Using deduction, one can derive new
    truths from other truths that are known to be
    true by intuition.

16
Descartes Method
  • Radical Skepticism
  • He will reject any belief that he cannot know to
    be true with absolute certainty. Any possible
    doubt will be reason for rejecting the belief.

17
Descartes
  • I was convinced that I must once for all
    seriously undertake to rid myself of all the
    opinions which I had formerly accepted, and
    commence to build anew from the foundation, if I
    wanted to establish any firm and permanent
    structure in the sciences.
  • Descartes begins with radical skepticism, radical
    doubt.

18
Descartes
  • I have delivered my mind from every care and am
    happily agitated by no passions and since I have
    procured for myself an assured leisure in a
    peaceable retirement, I shall at last seriously
    and freely address myself to the general upheaval
    of all my former opinions.

19
Descartes
  • It is not necessary that I should show that all
    of these former opinions are false.
  • If I am able to find in each one some reason to
    doubt, this will suffice to justify my rejecting
    the whole.

20
Descartes
  • the destruction of the foundations brings
    with it the downfall of the rest of the edifice.
  • I shall only in the first place attack those
    principles upon which all my former opinions
    rested.

21
Descartes
  • it is sometimes proved to me that the senses are
    deceptive.
  • although the senses sometimes deceive us there
    are yet many things known through the senses
    that we cannot reasonably doubt.
  • For example, there is the fact that I am here,
    seated by the fire, attired in a dressing gown,
    having this paper in my hands and other similar
    matters.

22
Descartes The Dream Argument
  • I must remember that I am a man, and that
    consequently I am in the habit of sleeping.
  • how often has it happened to me that in the
    night I dreamt that I found myself in this
    particular place, that I was dressed and seated
    near the fire, while in reality I was lying
    undressed in bed!
  • there are no certain indications by which we may
    clearly distinguish wakefulness from sleep.

23
Descartes the truths of mathematics and geometry
  • Arithmetic, Geometry and other sciences of that
    kind contain some measure of certainty and an
    element of the indubitable
  • For whether I am awake or asleep, 2 3 5, and
    the square can never have more than 4 sides, and
    it does not seem possible that truths so clear
    and apparent can be suspected of any falsity or
    uncertainty.

24
Descartes The Evil Genius Argument
  • I shall then suppose some evil God-like genius
    has employed his whole energies in deceiving
    me.
  • how do I know that Im not deceived every time
    that I add two and three, or count the sides of a
    square .
  • I shall consider that the heavens, the earth,
    colors, figures, sound, and all other external
    things are naught but the illusions and dreams of
    which this genius has availed himself in order to
    lay traps for my credulity.

25
Descartes Cogito Ergo Sum
  • I shall ever follow in this road until I have
    met with something which is certain.
  • I myself, am I not at least something?
  • I myself exist merely because I thought of
    something
  • Let the evil genius deceive me as much as he
    will, he can never cause me to be nothing so long
    as I think that I am something.
  • We must come to the definite conclusion that
    this proposition I am, I exist, is necessarily
    true each time that I pronounce it, or that I
    mentally conceive it.

26
Descartes The Wax Experiment
  • The famous wax thought experiment of the Second
    Meditation illustrates a procedure for uncovering
    what is innate to the mind.
  • The idea of body (extension in space) is not
    learned through the senses.
  • Melt a block of wax and all of its sensory
    qualities change. Is it the same wax? Yes. How do
    we know this? The idea of the wax body does not
    seem to come from sense experience..
  • The idea of body itself is an intuition of the
    mind. I know the mind better than anything else.

27
Arguments for Substance Dualism
  • The Conceivability Arguments
  • The Divisibility Argument
  • Near-Death Experiences

28
Conceivability Argument
  • Descartes argues for these points.
  • Having a body is not essential to him.
  • Having a mind is essential to him.
  • Mind and body are two distinct kinds of
    substances.

29
Conceivability ArgumentSee pages 86-88
  • It is conceivable for me to exist without a body.
  • Whatever is conceivable is possible.
  • Therefore, it is possible for me to exist without
    a body.
  • If body is essential to me, then it is impossible
    for me to exist without it.
  • So body is not essential to me.

30
Objection to theConceivability Argument
  • It does not seem possible to conceive of existing
    without a body. Try it. (See thought probe on
    page 90)
  • So Descartes cannot conclude that it is possible
    for him to exist without a body nor conclude that
    body is not essential to him.

31
Conceivability ArgumentThis part seems to be
sound?
  1. I cannot conceive of existing without a mind.
  2. Whatever is inconceivable is impossible.
  3. Therefore, it is impossible for me to exist
    without having a mind.
  4. Whatever is impossible for me not to have is
    essential to me.
  5. So having a mind is essential to me. (It is part
    of my nature, what I am.)

32
Conceivability Argument B
  1. Its conceivable for me to exist without having a
    body.
  2. I cannot conceive that I exist without a mind.
  3. Hence, body and mind have different properties.
  4. Leibnizs law If X and Y are identical, then
    they have all the same properties in common.
  5. Therefore, my mind is not identical to my body.
  6. Therefore, mind and body are two distinct kinds
    of substances.

33
Objection to Conceivability Argument B
  • We cannot always apply Leibnizs law
    (indiscernibility of identicals) to properties
    that are a result of our beliefs. Saying I can
    conceive that my car is red is different from
    saying My car is red. The first can be true
    even if the car is blue. (See example on next
    slide.)

34
Objection to Conceivability Argument B
  • I can conceive that Clark Kent is an ordinary
    human being.
  • I cannot conceive that Superman is an ordinary
    human being.
  • So, Clark Kent has a property that Superman
    lacks.
  • Therefore, by Leibnizs law, Clark Kent is not
    the same person as Superman.

35
Objection to Conceivability Argument B
  • Conceiving of objects X and Y does not make them
    different objects.
  • One and the same object can be described in two
    different ways. The names Evening Star and
    Morning Star refer to the planet venus. I might
    believe that they are different objects because I
    see them in different ways.

36
Divisibility Argument (p. 90)
  • Minds are indivisible, but bodies are divisible.
  • Leibnizs law
  • So minds are not identical to bodies.
  • Objection 1 Minds seem to be divisible. Cerebral
    Commissurotomy People who undergo this split
    brain operation seem to be left with split minds.
  • Objection 2 Minds may still depend
    (ontologically) on the body. Vocal cords can be
    divided, but the voice cannot be. But we cannot
    conclude that the voice can exist independently
    of the vocal cords.

37
Argument from Near-death experience
  • If substance dualism is false, then minds cannot
    exist independently from bodies.
  • But minds can exist independently from bodies.
    (See argument for this on the next slide.)
  • Therefore, substance dualism is true.
  • Note This is a deductively valid argument Modus
    Tollens (see page 31)

38
Argument from near-death experiences
  • Argument for the second premise in previous
    argument.
  • Hundreds of people report having experiences
    while being outside their bodies.
  • The best explanation for these reports is that
    minds can exist independently from bodies.
  • Therefore, minds can exist independently from
    bodies.

39
Near-death experiences
  • Is this the best explanation?
  • Oxygen deprivation or medical drugs can cause
    hallucinations.
  • When studying one person who had out of body
    experiences, they found that the persons angular
    gyrus was very active during these experiences.
  • Perhaps they are caused by other neurological
    processes in the brain.
  • These are simpler and more conservative
    explanations.

40
Objection The Biblical conception of the person
  • See page 87 for the Biblical conception of the
    person. There is unanimity among Biblical
    scholars that the Biblical picture of the person
    is non-dualist. The whole person dies, not just
    the body. Christ was resurrected body and soul.
    His body wasnt reunited with his soul.

41
Problem of Interactionism
  • How do minds and bodies interact?
  • There is no such thing as a nonphysical cause,
    but there would have to be if nonphysical minds
    interact with bodies. (Or is there evidence of
    this? Is telekinesis possible?)
  • Mind-body interaction would violate a fundamental
    law of physics the law of the conservation of
    mass-energy. If a mind interacted with a body,
    then energy would enter the physical world out of
    nowhere violating this law of conservation.

42
Objection to DualismThe problem of Interaction
  • Answers to the problem of interaction
  • Descartes Dualistic Interactionism
  • Parallelism
  • Occasionlism
  • Pre-established harmony
  • Epiphenominalism

43
Descartes Interactionism
  • The mind affects the brain at the pineal gland in
    the brain. (See page 94.)
  • But this does not overcome the objection that
    mental causation violates the law of the
    conservation of mass-energy.

44
Epiphenominalism
  • To overcome the objection that minds cannot
    causally interact with bodies (because that would
    violate the law of conservation of mass-energy),
    some have denied that minds have any causal
    power. But bodies have causal power on minds.
    Mind is an ineffective by-product of physical
    processes. The mind is to the body as smoke is to
    a fire.

45
Objections to epiphenomenalism
  • How does body cause mental processes?
  • It seems like the law of the conservation of
    mass-energy is violated again. Energy must be
    lost to the mental world if the physical world
    produces the nonphysical mental world.
  • Thoughts and feelings have no effect on the world
    or our behavior. But it the mental states do
    affect our behavior. (I pull my hand away from a
    hot pan that causes me pain.)
  • Creatures with minds are no better off than
    creatures without minds. Mind has no survival
    value.

46
Parallelism
  • The doctrine that the mind and body are two
    separate things and do not causally interact with
    each other. Mental processes and physical
    processes run parallel to each other. This solves
    the problem of interaction.

47
Occasionalism
  • The parallelist theory of the mind that claims
    the correlation between mental processes and
    physical processes are caused on each occasion by
    God.

48
Pre-established Harmony
  • The parallelist theory of mind that claims that
    the correlation between mental and physical
    events was established by God at the beginning of
    the universe when God created it. This was
    Leibniz view. God placed each monad in a
    pre-established harmony.

49
More Objections to Dualism
  • Brain problems affect our ability to think.
  • The problem of other minds
  • Solipsism
  • Ryle and the category mistake

50
Objection Brain problems
  • According to Cartesian dualism, we think with our
    minds and not our brains. If we think with our
    minds and not our brains, then when we lose brain
    functions (because of diseases like Alzheimers
    or accidents that cause brain damage), that
    should have no effect on our ability to think.
    But these diseases and brain problems seem to
    have serious effects on our ability to think. So
    it is false that we think with our minds and not
    our brains.

51
Problem of Other Minds
  • There is no way to tell if anyone (besides
    yourself) has a mind. Minds are nonphysical and
    cannot be seen or detected in any way. They are
    private to each individual.

52
Solipsism
  • How can Descartes know anything but his own mind?
    The only thing he knows for certain is that he
    has a mind. Unless he can prove that there is an
    external world and that other people have minds,
    the only thing he can know is the contents of his
    own mind. (He tried to prove that the external
    world exists and that he can know other things
    besides the contents of his own mind.)

53
Ryle and the category mistake
  • See page 106.
  • According to Ryle, dualists make a category
    mistake when they talk of minds being mental
    substances. A category mistake occurs when you
    talk about something in a way that treats it as
    something that it is not. For instance, suppose
    that you introduce your friends to the college,
    and you show them all the different buildings
    there. At the end of the tour they ask, But
    where is the college? You friends are making a
    category mistake. The college is not something
    else besides all the buildings that make it up.
    The same goes with the concept of mind. The mind
    is not something in addition to what is physical.
    To think so is to make a category mistake.

54
New arguments for dualismIntentionality
  • The best arguments for dualism rest on the
    attempt to find properties that distinguish minds
    from bodies.
  • Intentionality is one such property.
    Intentionality refers to a property of mental
    states. Some mental stateslike the thought of
    buying my mother a presentare ABOUT something
    else. In this case, my thought is about my
    mother. But it does not seem that objects can be
    about other things in the same way that mental
    states can be about things. To say that mental
    states have intentionality is to say that they
    represent something else. But physical objects
    are what they are and are not about other things.

55
Questions
  • Descartes identifies the mind with the soul. Is
    that correct? If not, how does the soul differ
    from the mind?

56
Questions
  • Some people also talk about spirits. Is that
    something different?

57
Questions
  • Suppose someone claimed to have a device that
    destroyed peoples souls. When it was used, it
    prevented a persons soul from going to heaven
    but otherwise had no discernible effect on that
    person. How would you evaluate such a claim?
  • Is the claim that people have souls any more
    plausible? Why or why not?

58
Questions
  • Is it possible to build a machine that has our
    linguistic and problem solving abilities?
  • If a machine had these abilities, would it have a
    mind?

59
Questions
  • Descartes did not think that animals have minds
    because they do not behave in ways that cannot be
    accounted for in purely mechanical terms. Do
    animals have minds?
  • If they do, then can we justify killing and
    eating them or using them for experimentation?

60
Questions
  • Thomas Jefferson said that to talk about
    immaterial existences is to talk of nothings. Do
    you agree or not? Why or why not?

61
Basis of PhysicalismEmpiricism
  • Empiricism The only source of knowledge about
    the external world is sense experience. The mind
    is a blank slate waiting to be filled.
  • British empiricists
  • John Locke
  • David Hume
  • Bishop Berkeley

62
PhysicalismTwo Corollaries of Empiricism
  • An idea corresponds to a real object only if it
    is derived from or reducible to sense
    impressions.
  • A term is meaningful (has meaning) only if it
    stands for a real object.

63
PhysicalismEmpiricism
  • An example of how an empiricist thinks about
    mind Hume rejects the idea of the soul (an
    immaterial substance) because there is no sense
    impression that can be connected to it. The word
    soul stands for nothing and is meaningless.

64
PhysicalismLogical Positivism
  • The Vienna Circle
  • A group of 20th Century philosophically minded
    scientists and philosophers.
  • Philosophy makes sense of science
  • Eliminate meaningless metaphysical speculation.

65
Logical Positivism
  • The Verifiability Theory of Meaning
  • The meaning of a sentence is its method of
    verification through sense experience.
  • To know the meaning of a sentence is to know what
    observable differences in the world it would make
    if it were true (or false).

66
Logical Positivism
  • According to the Logical Positivist view, here
    are some meaningless statements
  • The nothing nothings. (Heidegger)
  • The absolute is infinite. (Hegel)
  • Being is eternal. (Parmenides)
  • The strings of string theory exist. (This would
    be meaningless if string theory cannot be
    connected to experimental tests.)

67
PhysicalismLogical Behaviorism
  • Can sentences about mental states be meaningful?
    (e.g., Joe is in pain.) We have to connect these
    sentences with sense experiences.
  • We can tell what mental state a person is in by
    observing his or her behavior.
  • Mental States behavioral dispositions
  • Behavioral Disposition The tendency to respond
    in certain ways to certain stimuli.

68
PhysicalismLogical Behaviorism
  • Having a mental state Having a disposition to
    behave in certain ways given certain stimuli
  • The mental state IS the disposition
  • B.F. Skinner To make talk of mental states fit
    scientific discourse, replace all mental terms
    with terms referring to descriptions of behavior.
    There is no mind existing behind the behavior,
    and no need to talk of belief, pain, etc.

69
Logical Behaviorism
  • How would a behaviorist transform the following
    sentences?
  • Henry is angry with Maud.
  • Thor believes that he is ugly.
  • Niki wants to become rich.
  • Aronian has learned Spanish well.
  • Kenny thinks the Colbert Report is funny.

70
Logical Behaviorism seems more adequate than
Cartesian Dualism
  • Simpler Reductive, materialist theory. No need
    to assume any immaterial minds
  • More Conservative Fits our beliefs about the
    conservation of energy, and the causal closure of
    the physical
  • More Fruitful Solves problem of other minds.
    Minds are observable. There is no trouble
    admitting intelligent robots. They will have
    mental states, too.

71
Logical BehaviorismBenefits of Behaviorism
  • Behaviorism has implications for how we treat
    mental illness. If we want to alter a persons
    mind, then all we have to do is change the
    persons behavior.
  • Behaviorism helped psychologists overcome the
    problem that people are poor reporters of their
    own subjective mental states. For instance, to
    find out which hurts more, piercing ones navel
    or ones nose, it is better to measure behavior
    than ask subjects to compare their pains. We can
    understand people in terms of stimuli, responses,
    and conditioning.

72
Logical BehaviorismTest Its Definition of
Mental States
  • Mental state X if and only if behavioral
    disposition Y.
  • If mental state X, then disposition Y
  • If disposition Y, then mental state X
  • Can we refute one of these? Is it possible to
    have one side but not the other?

73
Test Logical Behaviorism
  • The Perfect Pretender, p. 108 (Qualitative
    Content The felt quality of certain mental
    states)
  • Putnams Super-Spartans, p. 108
  • Mental states seem to be causes of behavior, not
    identical with behavior
  • Noam Chomsky If LB were true, then it would be
    possible to predict our future behavior from our
    past behavior. But people display completely
    novel verbal (linguistic) behavior.

74
Logical Behaviorism
  • The verifiability criterion of meaning is itself
    unverifiable. It cannot be verified by any
    possible observations. So it must be a
    meaningless statement, too.
  • So talk using traditional mental state terms is
    not necessarily meaningless.

75
PhysicalismIdentity Theory
  • Phineas Cage Damage to brain caused change in
    personality and mental functioning.
  • Other evidence that brain states (a pattern of
    neurons firing) are connected to mental states.
  • Mental states are identical to brain states.
  • Strong Identity Theory
  • One type of brain state is identical to one type
    of mental state.

76
Identity Theory andLogical Behaviorism
  • Suppose that you are going through a difficult
    time in your life. When you go to bed, you start
    thinking that your life is empty and meaningless.
    You are tired of these thoughts and you want to
    change your mind. You want to get rid of these
    depressing late-night thoughts.
  • If behaviorism is true, how would you go about
    changing your mind?
  • If identity theory is true, how would you go
    about changing your mind?

77
Identity Theory
  • Simple Reductive, no need for immaterial
    substance.
  • Fruitful makes predictions. For instance,
    doctors can stimulate the brain and cause smells,
    sights, and sounds. It also explains mental
    causation, how mental states can cause behavior.

78
Test Identity Theory
  • Identity and Indiscernibility
  • Conscious experience brain states are knowable
    by empirical investigation, but mental states are
    not. (see Nagels, What is it like to be a bat?,
    p. 115)
  • John Lorber (p. 115). Radically different brain
    states can give the same mental state. So
    identity theorists cannot say what it is to be in
    a particular mental state. No one type of brain
    state can be correlated to one type of mental
    state.

79
Test Identity TheoryMultiple Realizability
Problem
  • Lewiss Pained Martian(p. 116) If IT were true,
    then only creatures with brains could have mental
    states. But it seems logically possible that
    creatures without brains could have mental
    states.
  • If it is logically possible to have thinking
    machines made of silicon chips, then identity
    theory is false. (John Searles thought
    experiment imagine replacing your brain slowly,
    piece by piece, with silicon chips. Page 119.)
  • See page 121 on Neural Chips.

80
Functionalism
  • Mental states Functional states
  • A functional state is defined in terms of what it
    does, not what it is made of.
  • Example, clocks can be made of many different
    kinds of materials, but they all have the same
    function.
  • So functionalism solves the multiple
    realizability problem, the problem that it is
    possible for things other than brains to have
    minds.

81
Functionalism vs. Behaviorism
  • Mental states are defined by their causal role.
  • Behaviorism Defines m-states in terms of
  • Physical stimulus ? behavior output response
  • Functionalism Defines m-states in terms of
  • Physical stimulus and mental state ? behavior
    output and mental state change
  • (1) So mental states can be causes of behavior
  • (2) Mental states are related causally to other
    mental states

82
Functional States of Coke Machine
State 1 State 2
50 Cents input No output Go to State 2 Dispense 1 Coke Go to State 1
1 Dollar input Dispense 1 Coke Stay in State 1 Dispense 1 Coke Return 50 cents Go to State 1
83
Functional State TableMachine Table
State 3 State 1 State 7 State 4 State 5 State n
Input 1 State 4 Output 2 State 4 Output 9 State 5 Output 3 State 4 Output 4 State 1 Output 2 State x Output y
Input 4 State 5 Output 2 State 7 Output 1 State 2 Output 2 State 3 Output 8 State 7 Output 6 State x Output y
Input 5 State 2 Output 5 State 1 Output 8 State 2 Output 4 State 6 Output 3 State 4 Output 2 State x Output y

Input n State x Output y State x Output y State x Output y State x Output y State x Output y State x Output y
84
FunctionalismMind as Software Version
  • To have a mind is to have the ability to perform
    certain functions
  • Programs determine how computers function.
  • Strong AI There is nothing more to having a mind
    than running the right kind of software. (pp.
    126-127)

85
Evaluating Functionalism
  • Lewis Pained Madman (p. 128) it seems possible
    that a person could be in a mental state, like
    pain, but this pain state could have an entirely
    different function than it normally has.
  • So being in a certain functional state is not a
    necessary condition for being in a certain mental
    state. To be in pain, you do not have to be in
    any particular functional state.

86
Evaluating Functionalism
  • Ned Blocks Chinese Nation (p. 129) Having the
    right sort of functional organization is not
    sufficient for having a mind.
  • Absent Qualia Objection It is possible to have
    something that is functionally equivalent to a
    human being but not have conscious experience
    (qualia, raw feels, felt quality)

87
Evaluating Functionalism
  • Putnams Inverted Spectrum (p. 130) Something
    that is functionally equivalent to a human being
    could have the wrong kind of conscious
    experience. So having a certain functional state
    is not sufficient for being in a certain mental
    state.
  • There must be something more to being in a mental
    state than being in a certain functional state.
  • Example of Synesthesia (p. 132)

88
Functionalism
  • Paul Churchlands Response to Objections the
    qualitative experience associated with a mental
    state is irrelevant to it.
  • But are qualia irrelevant?

89
Functionalism
  • The Turing Test (pp. 133-134). There is nothing
    more to being intelligent than being able to use
    language as we do.
  • See the Loebner Prize (p. 138)

90
Evaluating Functionalism
  • Searles Chinese Room (p. 136) It is possible to
    pass the Turing Test (have the correct functional
    state) and yet not have any understanding of the
    language used (not have the corresponding mental
    state). A machine can manipulate symbols but not
    assign any meaning to the symbols.
  • Computers make sentences by combining symbols
    according to their physical features or form
    (syntax), but people manipulate symbols on the
    basis of their meaning or content (semantics).

91
Evaluating Functionalism
  • Searles Chinese Gym (p. 140) A thought
    experiment to show that connection machines
    (parallel processing) will fare no better than
    sequential processing machines.

92
Evaluating Functionalism
  • See Blocks Conversational Jukebox (p. 142). This
    is like the Chinese Room objection. A machine
    could produce answers to questions like a human,
    but not have a mind or intelligence.

93
Evaluating Functionalism
  • The Total Turing Test (p. 140)
  • Would passing this test be necessary or
    sufficient for having intelligence and a mind?

94
Functionalismand Intentionality
  • Intentionality (p. 141) Thoughts can be about
    things. Any adequate theory of mind must explain
    how mental states can be about something else.

95
Functionalism
  • Nevertheless, a machines passing the Turing test
    is evidence for its being intelligent and having
    a mind. How far should we go to recognize this
    possible intelligence? Should we ever give
    machines rights or equal moral consideration?
  • What about animals? They seem to have minds that
    are similar to ours in certain respects. Should
    we give them equal moral consideration or rights?
    Why or why not?

96
Should We Ban Artificial Intelligence Research?
  • Some scientists are so concerned that intelligent
    machines may threaten our existence that they
    want to ban all research into artificial
    intelligence.

97
Functionalism
  • Check out Chatterbots or chatbots.

98
Eliminative Materialism
  • The Hard Problem How can we explain the fact of
    conscious experience? How is it possible to
    explain how physical processes give rise to
    experience?
  • Reductive materialism has failed.
  • Eliminative materialist answer Reductive
    theories fail, so there are no mental states.
    They do not exist.

99
Eliminative Materialism
  • Arguments for
  • Richard Rortys Demons (146)
  • Folk Psychology is weak (148, quote)
  • Arguments against
  • Searles Chevrolet Station Wagon (149)
  • Jacksons Color-Challenged Scientist (150 and in
    the news 151)
  • Chalmers Zombies (152)

100
Eliminative Materialism
  • Rortys Demons (p. 146). The absurdity of
    saying Nobody has ever felt a pain is no
    greater than that of saying Nobody has ever seen
    a demon.
  • All references to mental states will someday be
    eliminated from our psychology textbooks.

101
Eliminative Materialism
  • Folk Psychology This is our common sense theory
    of the mind. It is our talk about beliefs, pains,
    desires, hopes, fears, etc. But this theory
    doesnt explain much. (See Churchland quote on
    page 148) So it will be replaced by a better
    theory that does not rely on beliefs, desires,
    etc.

102
EvaluatingEliminative Materialism
  • Jacksons Color-Challenged Scientist (p. 150).
    Read about Seeing Color for the First Time (p.
    151). Subjective experience (its qualitative
    content) cannot be eliminated. A complete account
    of the world cannot be given in purely physical
    terms. Physicalism must be false.

103
Eliminative Materialism
  • If Zombies are logically possible, then
    consciousness is nonphysical, or it is not
    identical to or reducible to physical states.

104
Property Dualism
  • There can be no complete description of the world
    in purely physical terms.
  • Mental states have (a) qualitative content and
    (b) intentional content that are neither physical
    nor functional properties.
  • These are primitive properties cant be
    explained in terms of anything more fundamental.

105
Property Dualism
  • Arguments For
  • Jacquettes Intentionality Test Intentionality
    is primitive.
  • Nonreductive explanations of basic properties
    (158) EMC2 Fma
  • Panpsychism (159) Everything has mental
    properties from the beginning.
  • Emergentism (160) mental properties emerge from
    things lacking those properties. (link)

106
Emergentism
  • Consciousness is an emergent property. Our
    neurons are not conscious but once they become
    related to one another in the right sorts of
    ways, consciousness emerges.
  • Downward Causation The mind has causal effect on
    the body. Link

107
Downward Causation
  • Emergent properties can have causal influence on
    the physical elements that bring them into being.
  • Evidence
  • Biofeedback (162) control neuron firing rates
  • Placebo/Nocebo effects (163)
  • Cognitive behavior theory (163)

108
Emergent God
  • See page 165

109
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110
First Consider your answers to these questions
true or false?
  • It is possible for my mind to survive the death
    of my body.
  • It will be possible to build machines that have
    minds like people.
  • The best way to treat depression is to change the
    chemical reactions inside my brain.
  • Sometime in the future, it might be possible for
    a crazy scientist to create false memories in my
    mind by simply injecting certain chemicals into
    my brain.
  • Scientists can understand the nature of clouds,
    planets, black holes, and other objects, they
    will never understand the true nature of emotions
    like anger, love, or hate.

111
Continued true or false?
  • Dogs and cat have beliefs and hopes just like
    humans do.
  • My thoughts and ideas are the product of my
    environment and upbringing.
  • There might exist conscious beings on other
    planets who do have beliefs and self-awareness
    but who do not have brains like ours.
  • It is impossible for machines to be creative or
    funny. One could never be a stand-up comedian.
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