[Paleopsych] New Scientist: Simon Blackburn: The world in your head

Premise Checker checker at panix.com
Sun Jan 23 18:31:27 UTC 2005

The world in your head

        New Scientist vol 183 issue 2464 - 11 September 2004, page 42

     Are you a qualia freak? A zombie? Can our inner world of sensation,
     colour and subjective experience ever be completely explained? Simon
     Blackburn weighs up three attempts to reconcile the mystery that is
                  consciousness with a scientific world view

       NEAR enough 300 years ago, the great Gottfried Leibniz said two
     interesting things about consciousness. One was that if there were a
    machine for producing conscious experiences such as perceptions, then
     even if it were as big as a mill so that we could walk around among
     the wheels we would find "nothing but pieces which push one against
          the other and never anything to account for a perception".

      His other remark was by way of rebuke to John Locke. Locke thought
         that it was just "God's good pleasure" to "annex" different
    sensations, such as pain, to various processes of brain and body, such
    as those caused by a pinprick. Leibniz insisted that it was "not God's
       way to act in such an unruly and unreasoned fashion". Rather the
    relation between the "motions" that being pricked by a pin produces in
    the body, and the felt pain, must be open to understanding and reason:
      in Leibniz's own analogy, it should be something like the relation
     between a circle and its projection onto a plane at an angle to it.
      Stripped of the theological dressing, the point is that we do not
      understand the relation between mind and body if their connection
      might as well be pure happenstance, luck or accident, rather than
                            understood necessity.

        Part of the interest of Leibniz's two remarks is that they fit
    together uncomfortably. If delving into fine physical and neurological
    detail is not going to explain the emergence of consciousness, as the
     first remark suggests, then how will we reach the eureka moment that
      the second remark promises, the illumination when the relationship
        between brain and consciousness becomes as obvious and open to
       rational understanding as that between a circle and a projected
       ellipse? Leibniz seems to have combined a stringent condition on
    solving the problem with pessimism about our only avenue to satisfying

     We have not got brains as big as mills, but we have made up for that
      by inventing a plethora of tools for discriminating events in the
       brain at ever-increasing levels of detail. Scientists can locate
    synaptic connections in space and time, and plot families of pathways
       between areas of brain activity. Each of the works under review
      delights in the complexities that are uncovered almost daily. They
      savour the staggering numbers: 30 billion neurons in the cerebral
       cortex alone; a million billion synapses. They go on to describe
    two-way interconnections, simultaneous activations of different areas,
     as well as the surprising examples of functions taking place without
    conscious experience at all, as in the famous cases of blindsight, and
     other clinical surprises. It is tempting to hope that with all these
    new facts at our disposal, we can prove Leibniz's pessimism unfounded.
                  Plenty of writings promise us that we can.

    The problem of consciousness, if there is one, arises acutely within a
     framework that almost all scientists and philosophers of mind share.
     This is the view that all conscious processes, and indeed all mental
     processes of any kind, are dependent upon the activity of the brain
      and central nervous system. In modern debates, this is not open to
      dispute. But within that consensus, there is still the question of
    just how the dependency works. Are there laws that relate the physical
                       and the mental, and if so, why?

     A century ago people talked of "emergence": mental activity somehow
    emerged out of brain activity, like Venus popping out of the sea. But
    that sounds mysterious, little better than René Descartes' speculation
     that there was a window between the body and the soul located in the
      pineal gland. More recent philosophers talk of mental processes as
    "supervening" on physical processes. Supervenience sounds soothing. It
           is supposed to be an intelligible version of emergence -
    Leibniz-friendly emergence, as it were, although not everyone believes
                         it deserves that reputation.

     In his 1996 book The Conscious Mind, the philosopher David Chalmers
      felicitously distinguished between problems of consciousness that
    might be solved by relatively normal science, and what he called "the
         hard problem", the problem that bothered Locke and Leibniz.

     The problems accessible to normal science are all those about mental
    functioning. How does the brain integrate data from different sources?
    How do long-term and short-term memory interact? What are the effects
     of damage here or there in the brain? What are the causes and limits
      of blindsight or of synaesthesia? Any question framed in terms of
       human perceptual functioning, or motor or other functions, is in
    principle accessible to scientific understanding, just as the engineer
       can relate the functioning of the computer chip to its internal
    architecture. Here, Leibniz's demand for an intelligible relationship
                                is satisfied.

     By contrast, the hard problem is variously phrased in terms of inner
    life, the phenomenological feel of things, or the "what it is like" of
      philosopher Tom Nagel's famous question, "What is it like to be a
    bat?" It tries to get a grasp on private experience itself, the river
     that stops only with dreamless sleep, anaesthesia or death. It says
    that there is an inner dimension to our lives, which is of fundamental
     importance. Indeed it makes up our whole awareness of ourselves and
     our world. But the hard problem is to integrate that inner dimension
                       into the scientific world view.

    Philosophers (and lay people) thinking about this tend to divide into
     two camps. There are those who take the hard problem seriously. And
     then there are those dismissive, harder-headed theorists who believe
     the whole idea of a hard problem is a kind of illusion. Once we have
    done what the computer engineer can do, and have explained everything
      about human functioning and the mechanisms on which it depends, we
                          have explained everything.

         Hard-headed types come in different flavours: reductionists,
       functionalists or mind-brain identity theorists. Whatever their
    differences, they join in dismissing the first group as qualia freaks
    (qualia are the felt or phenomenal properties of conscious events: the
     painfulness of my pain, felt only by me, for example). Qualia freaks
     reply that reductionists are insensitive to the difference between a
      normal person and a zombie, thought of as an unconscious physical
     duplicate, a thing whose functioning is fine but whose awareness is

    Here are some diagnostics for whether you believe in the hard problem.
     Do you find it completely mysterious that the grey brain can produce
      the yellow perceptual experience? Do you wonder if a sufficiently
    large piece of visual cortex alive in a Petri dish might be producing
       such experience? Do you think that although there are conscious
      experiences, perhaps they are causally inert, having no effect on
        bodies and brains? Do you think it a bare possibility, even if
      unlikely, that you are the only conscious agent on Earth, and that
    other people are all zombies? If you are tempted to answer yes to most
             of these questions, you believe in the hard problem.

     A generation ago, most scientists would not have done so. They would
      have thrown in their lot with reductionism of one kind or another.
    Science deals with what can be observed, measured and repeated. Human
    reactions, and their neurophysiological bases, can be operationalised.
    So the line of least resistance is to deny anything further, anything
     subjective, which cannot. In psychology, this attitude characterised
    behaviourism, although more sophisticated functionalist views have now
       overtaken it. Curiously enough, however, recent neuroscience has
    tended to sympathise with qualia freaks, as the titles or subtitles of
      these books illustrate. Each writer believes that there is a hard
     problem, although Christof Koch holds that we can eventually make it
    disappear by solving enough easy problems. Each hopes that science can
                           at least creep up on it.

       A number of developments help to explain this change. One is our
        increased awareness of the sheer amount of brain activity, and
     sometimes personal activity, that bypasses consciousness altogether.
       Many complex sensory-motor reactions are not conscious, and many
       precede any conscious awareness of the environmental cause that
     triggered them. So it becomes impossible simply to equate conscious
      processes with complex functional states of brain and body, for we
          know of too many such states that have nothing to do with
    consciousness, and work well enough or better without it. Over most of
     its activities, a brain is a cluster of small zombies, so we have to
      postulate something beyond mere function in cases where it is not.

         A second development is our increased awareness of possible
    dissociations between events giving rise to conscious experience, and
     behaviour expressive of that experience. This makes it attractive to
    think of the conscious experience as something over and above whatever
      it does, for it may exist without doing anything much at all. This
      kind of problem is particularly prominent in Jeffrey Gray's book,
       where the dissociation between visual experience and its normal
           function is highlighted in experiments on synaesthesia.

      There are difficulties ahead, however, if you believe in the hard
      problem. A satisfactory theory of consciousness should protect the
      idea that consciousness is a good thing. Consciousness makes human
    life possible. It makes us do things that we might otherwise not have
       done, and its utility presumably provides the rationale for its
      evolutionary development. Gerald Edelman is the most forthright of
       these writers to deny this. He argues that conscious states lie
      outside the causal order altogether. Physics says that it takes a
    physical cause to produce a physical effect, and in Edelman's picture
       the "phenomenal transform" or conscious discriminations that are
    themselves the result of underlying neural events can have no effects
    of their own; in the tradition, this is called epiphenomenalism. It is
        natural to worry that in that case they are just paint on the
      machinery, and might as well not exist. But in Edelman's view they
        have to exist although they do nothing: they are "entailed" by
     sufficiently complex underlying neural states. Entailment here means
    that there is no possibility of the underlying neural states existing
      without the supervening consciousness: there is no possibility of
      zombies. There was, as it were, no remaining Lockean act of "God's
    good pleasure" to superadd the conscious events on top of the physical
                      events, or to paint the machinery.

       In the philosophical literature, there are two models of how to
      understand such an entailment, or in other words to get rid of the
      idea of any disturbing Lockean remainder. One, made famous by Saul
      Kripke and Hilary Putnam (both these philosophers oppose identity
     materialism), is to assimilate the case to the identity of water and
          H[2]O: God or nature had only to make H[2]O (at the right
    temperature). It took no further dispensation to make water. The other
    is the Leibnizian model of rational or intelligible analysis, enabling
    us to see conscious activity as somehow implicit in the right kind of
     physical activity. The first of these suggests that there is no hard
      problem at all: there is only the embodied brain and its physical
       properties. The second seems equally to require a functionalist
    dismissal of the hard problem, since it is precisely the hard problem
        that stands in the way of an intelligible relationship between
                         conscious events and others.

    Readers will need to decide for themselves whether Edelman's approach
     fits either model, or whether instead, by first cherishing the hard
    problem, and then helping itself to unexplained entailment, it really
      suggests only a new name for old-fashioned emergence: magic tissue
                         secreting a magical effect.

      A related difficulty is that Edelman is suspiciously silent about
    another classic problem for qualia freaks: if conscious processes have
      no causal consequences, it remains very obscure how we could know
     about them, and still more how we could remember them. Indeed, these
      problems lie at the heart of Ludwig Wittgenstein's famous "private
     language argument" against the cluster of ideas that animate qualia
                    freaks and motivate the hard problem.

    Each of these books is stimulating and provoking, and contains a mine
     of information. The book by Koch, a collaborator of the late Francis
     Crick, is the heaviest, both in the sense of the largest and the one
    that goes furthest into neurological and biological detail; his index
       alone occupies 60 dense pages. Edelman's Wider Than the Sky, as
            already hinted, is the most forthright and confident.

     But Jeffrey Gray's Consciousness: Creeping up on the hard problem is
       remarkable both for the clarity of its expositions, and for the
    patience with which he explores the prospects for integrating the hard
    problem into normal science. He does not shrink from counterintuitive
     conclusions: one of the sections is called "the world is inside the
     head", and goes on to defend the philosophically unfashionable view
         that the consciously perceived world is not the real world.

    We should applaud the sensitivity to philosophical issues that each of
    these writers shows. They illustrate that just as philosophers of mind
     must know outlines of the latest scientific thinking, so scientists
      wrestling with these matters do well to cultivate a philosophical
        sensitivity. As Koch admits, scientists need to listen to the
    questions philosophers pose, even if they don't listen to the answers
     they give. One question we need to prioritise is whether there is a
     hard question or only a plethora of moderately difficult ones. Here,
    as scientists like to say, more money is needed for further research.

                               Simon Blackburn

       Simon Blackburn is professor of philosophy at the University of

More information about the paleopsych mailing list