Consciousness in a Physical World

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Consciousness in aPhysical World

• Or How I Learned to Stop Worrying and Love the
  Mind
• The University of Alabama at Birmingham, April
  18, 2002
• Torin Alter

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The Modern Philosopher
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The Shape of the Problem
Consciousness ?
Physical World
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Dilemma

• EITHER
• Revise our conception of consciousness change
  the pegs shape.
• OR
• Revise our conception of nature change the
  holes shape.

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Organization

• The Hard Problem of Consciousness
• Why Consciousness Must Be Physical
• Why Consciousness Cant Be Physical
• An Intriguing Alternative Theory
• Consciousness and the Rest of the Mind

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Terminology

• Consciousness is multiply ambiguous
• Awake (Dilberts friend is unconscious) ?
• Knowing something (Hes conscious of your
  presence) ?
• Ability to introspect or report what youre
  thinking (related to self-consciousness) ?
• Subjective experience phenomenal character, what
  its like for the subject to undergo experience ?

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More Terminology

• Physical properties (roughly) those whose
  natures are revealed by some ideal physical
  science.
• Fundamental mass and charge?
• Non-fundamental shape, weight, being a rock,
  functional properties (propensity of light switch
  to cause lights to go on when switched up).

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The Hard Problem(David Chalmers)

• Part 1 (existence) How could a physical system
  such as a brain give rise to consciousness
  experience? Why dont objective brain processes
  take place without any accompanying subjective
  experience?
• Part 2 (distribution) Why do certain kinds of
  brain processes correlate with certain kinds of
  experiences and not others?

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Easy Problems

• How does the brain process and discriminate
  environmental stimulation?
• How does it integrate information?
• How do we produce reports on internal states?
• How do we access information and use it to
  control behavior?

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What Makes Them Easy?

• Problem explain how a certain function is
  performed.
• Solution specify mechanism.
• Example genetics.
• Target explain the function and transmission of
  hereditary traits.
• Mechanism DNA biology.
• Result Mendels gene is reductively explained.

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Why Is Explaining Consciousness Hard?

• After explaining functions, the questions remain
• Why is the performance of those functions
  accompanied by subjective experience?
• Why this kind of subjective experience?

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Is This Just Scientific Ignorance?

• Analogy How could a body be alive?
• That problem looks hard too. Must we posit some
  élan vital (irreducible life force)?
• In fact, its really just a bunch of easy
  problems
• Explaining physical growth, independent movement,
  reproduction, etc.

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Not So Fast!

• Life
• Target explain functions physical growth,
  independent movement, reproduction, etc.
• The only remaining mystery about being alive
  concerns consciousness.
• Consciousness
• Target does not appear to be a function.

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Consciousness As a Physical Phenomenon

• Physicalism (a.k.a. materialism) the world is
  entirely physical the peg is round.
• The physical facts exhaust the facts fix the
  physical properties, and the properties of
  consciousnessthe phenomenal propertiesfollow.
• Follow is logical, not merely natural.

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Why Consciousness Must Be Physical

• Occams Razor simpler theories are more likely
  to be true.
• Simpler parsimony fewer kinds of basic
  entities and basic laws.

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Dilberts Theory

• Consciousness an ability to predict and then
  observe the results of actions.
• Dilberts theory, like all versions of
  physicalism, passes the parsimony test no basic
  phenomenal properties or laws, in addition to
  physical properties and laws.
• If we deny physicalism, then we face

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The Threat of Epiphenomenalism

• The physical world is more or less causally
  closed for any given physical event there is a
  purely physical explanation (notwithstanding a
  bit of quantum indeterminacy).
• So, there is no room for nonphysical
  consciousness to do any independent causal work.
  Even if consciousness were absent, our behavior
  would have been caused in exactly the same way.
• So, denying physicalism may lead to
  epiphenomenalism (Huxley, 1874).

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Epiphenomenalism

• C C C C
• P P P P

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Why Consciousness Cant Be Physical

• Arguments From Crazy Science-Fiction Examples
• Mary
• Inverted spectrum
• Zombies

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Act 1 of the Mary Case
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Act 2
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The Inverted Spectrum
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The Inverted Spectrum

• What color will he say ripe tomatoes are?

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Actual Cases?

• Genetic abnormality R-cones have response
  pattern usually associated with G-cones, or vice
  versa this causes red-green colorblindness.
• If both abnormalities occur together, this might
  cause red-green inversion.

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The Challenge To Physicalism

• A logical possibility functional/physical
  duplicates who are red-green inverted.
• So, contrary to physicalism, fixing the physical
  facts leaves open different possibilities for the
  distribution of consciousness.

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Zombies

• Zombie physically (and functionally)
  indistinguishable from an ordinary human being,
  but without any consciousness.

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Not These Kinds of Zombies
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This Kind Philosophical Zombies
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The Zombie Challenge

• If zombies are logically possible, then fixing
  the physical properties leaves open the existence
  of consciousness physicalism fails.
• Zombies seem logically possible no apparent
  contradiction in their description.
• Think of logically possible worlds as those God
  could have created, had God so chosen.

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Logical Possibility
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General Argument Form

• Step 1 Establish an epistemic gap (from episteme
  knowledge).
• Step 2 Infer an ontological gap (from onta
  existing things, and logos science).

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Is Step 2 Legitimate?

• Does conceivability show logical possibility?
• Possible counterexample water without hydrogen.

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What Does the Water/H20 Discovery Show?

• Water/H20 discovery constrains only how we
  describe logical possibilities worlds without
  H20 should not be described as containing water,
  even if they have a functional equivalent.

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The Underlying Issue

• Can (scientific) discoveries about the actual
  world show that the space of logical possibility
  is smaller than we thought?

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Structure and Dynamics

• A microphysical description of the world
  specifies a distribution of particles, fields,
  and waves in space-time.
• Those basic systems are characterized by their
  spatiotemporal properties, and properties such as
  mass and charge.
• Those properties are defined in terms of spaces
  of states with a certain abstract structure.
• Those states can change over time according to
  certain principles of dynamics.
• The microphysical descriptions entail complex
  macroscopic systems (chemistry, biology, etc.,
  emerge), but only structural and dynamic facts.

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A Solution

• The intrinsic features that physical relations
  relate are bits of consciousness, or phenomenal
  properties.
• No less crazy than epiphenomenalism?

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Panprotopsychism

• The intrinsic features of the universe are bits
  of proto-consciousness
• Consciousness comes from the combination of their
  intrinsic natures.
• Physical properties come from their extrinsic
  relations.
• The peg fits, but the shape of both peg and hole
  are changed.

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Moral

• The costs of rejecting physicalism are not as
  clear as may seem. Difficult issues about the
  nature of causality are at play.
• We should reject the following argument
• Some version of physicalism must be true, because
  naturalism requires it.

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Subjects of Consciousness

• One might defensibly deny that consciousness
  reduces to the physical. What about subjects of
  experience?
• Non-physicalists tend to be anti-reductionist
  about persons. They shouldnt be.

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Consciousness and Intentionality

• Intentionality (Brentano) aboutness,
  representation.
• Old view consciousness and intentionality are
  closely linked.

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Standard Contemporary Picture
Conscious Experiences (raw feels)
Propositional Attitudes
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The Fragmented Mind

• Propositional attitudes have intentionality.
• Experiences dont.

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Is the Mind Fragmented?

• Conscious experiences seem to be rich with
  intentionality.
• Your visual experience of a round object can be
  assessed for accuracy. For example, your
  experience is inaccurate if there is nothing
  round in the room.
• To be assessed for accuracy, must your experience
  be interpreted, like a string of words? Or is
  your experience inherently representational?

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Conclusions

• The Hard Problem is real.
• Whether consciousness is physical may depend on
  esoteric, quasi-technical issues, such as whether
  empirical discoveries can constrain the space of
  logical possibility.

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More Conclusions

• The consequences of denying physicalism are less
  clear than may at first appear.
• The standard picture, on which the mind is
  fragmented, is open to doubt.

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Final Conclusion

• Philosophers like science fiction.