A
ROLE FOR CONSCIOUSNESS
Article first published in Philosophy
Now 65 (Jan/Feb 2008), 22-24
DAVID
HODGSON
One of the great enduring
mysteries of science lies in the question What does consciousness do? Or more specifically, What if anything is
achieved by subjective conscious experiences, such as visual and auditory
experiences, conscious thoughts, and feelings such as pain and hunger, that is
not achieved by physical brain processes unfolding in accordance with physical
laws of nature?
Many scientists and philosophers would answer nothing. According to them, the physical world
operates in accordance with the laws of physics, chemistry and biology, and is closed
to being affected by anything non-physical.
Thus, any effects that conscious experiences may have can only come
about by virtue of physical brain processes that are associated with and
perhaps constitute these experiences.
This physicalist approach, however, raises the question
why, if all is achieved by physical processes operating in accordance with
physical laws of nature, are some of these processes associated with and
possibly constitutive of subjective conscious experiences, when this
association does precisely nothing.
From an evolutionary viewpoint, this would not seem to make sense: the selection of consciousness through the survival
and reproduction of conscious organisms strongly suggests that consciousness
confers an advantage on an organism that has it.
A possible answer is that somehow conscious experiences are
inevitably associated with certain advantageous physical processes, so
that when these advantageous processes were selected in evolution, consciousness
was selected with them. Just as, for
example, a polar bear can’t have the useful warmth of its coat without its
non-useful weight, we can’t have some kinds of useful operations carried out by
brains without the non-useful conscious experiences.
However,
nothing remotely plausible has ever been suggested as to why this should be so;
and indeed, the best suggestions offered by physicalists as to why brain
processes associated with conscious experiences are advantageous are to the
effect that they carry out useful information-processing – which is just what
can be done, without consciousness, by a computer. This has led some physicalists to suggest that consciousness is a
kind of fiction, or that computers are (or with more processing power will become)
conscious; but these suggestions are I suggest highly unlikely to be true.
So, no plausible role for consciousness has been suggested
by physicalists. Now there are
scientists and philosophers who oppose the physicalist view, and who argue on
evolutionary and other grounds that consciousness must have an advantageous
role; but somewhat surprisingly, there is a dearth of suggestions from them too
as to a plausible role for consciousness.
I want to offer a specific and straightforward proposal as
to what the role of consciousness is:
Consciousness enables an
organism to be responsive to circumstances grasped as wholes, not just to
constituent features that can engage with laws or rules.
To expand a little:
The evolutionary advantage
of consciousness is that it enables an organism to determine and/or shape a
response to circumstances facing it that has regard, not only to features that
can engage with laws of nature and/or computational rules, but also to whole
combinations of features that are particular and perhaps unique to the
circumstances and cannot as wholes engage with laws or rules.
Subjectivity, Qualia and Unity
My
suggested role takes account of three striking and puzzling features of
conscious experiences: subjectivity,
qualia and unity.
First, subjectivity. Conscious experiences are experiences had
‘from the inside’ by a conscious subject.
They are not like objective features of the world, equally available for
observation by anyone in a position to observe them. Other people may know that I am in pain, but only I feel my
pain. Conscious experiences are part of
a subject’s take on the world; and it is reasonable to think that these
experiences contribute to the subject’s response to the world.
Second, qualia. Conscious experiences have features or
qualities that go beyond the physical features that seem to cause them: the look of colours, the feel of pain, and so on.
These features have been called qualia.
For example, there seems to be nothing about wavelengths of electromagnetic
radiation, or physical brain processes caused by visually encountering them,
that captures or explains the actual look of a blue sky. Although a computer can display blue on its
screen, there is no reason to think a computer actually experiences the colour
blue or knows what the colour blue looks like.
And third, unity. A conscious experience is a unity in the
sense that many features are experienced all-at-once by the subject. This is particularly striking in the case of
visual experiences, in which a subject is aware of many features of an observed
scene, and generally grasps them all-at-once in a whole unified experience or
‘gestalt’. How this happens, when
different features such as shapes and colours are processed by different parts
of the brain, is itself a mystery, which has been called the binding problem of
consciousness. Again, while a computer
can process features of information it has by operations determined by
computational rules, there is no reason to think that it can grasp combinations
of features as whole gestalts
Laws, Rules and Gestalts
I need to
say a bit more about features that can engage with laws of nature and/or
computational rules, and combinations of features that cannot as wholes engage
with them.
It is characteristic of laws and rules that they apply
generally over a range of circumstances, and must engage with types or
classes of things or features that different circumstances have in common,
and/or variable quantities that can engage with mathematical rules; so
that while laws and rules can apply to individual unique circumstances, they engage
with features of these circumstances only in so far as each of these features
is of a type or class, and/or is a variable quantity. Laws and rules link categories (say, X, Y, Z, etc.), where these
categories are types or classes of things or features, and/or mathematical
variables. In the case of computational
rules, X may be a potentially recurring situation in a computational program,
and Y may be the consequential operation to be undertaken in that situation.
Circumstances encountered and perceived by living organisms do have
constituent features that are common to different circumstances, and thus could
be features that engage with laws or rules.
Even simple qualia, had in common by different subjects and/or by the
same subject at different times, could do so.
However, each set of circumstances also has combinations of features that
are not of a type or class but are particular and perhaps unique to that set of
circumstances; and except to the extent that these combinations of features
might be adequately represented as wholes in terms of types and mathematical
variables, they cannot as wholes engage with laws and/or rules.
When a conscious organism such as a human being experiences
circumstances facing it, features of what is experienced are combined into
unified gestalts, such as visual experiences combining many features of an
observed scene. I have argued in detail
elsewhere that, since these feature-rich experiences are combinations of
qualia, they cannot be adequately represented in terms of types and
mathematical variables; and since they are particular and perhaps unique
combinations of features, they cannot as wholes engage with laws or rules. My suggestion is that, although these
gestalts cannot as wholes engage with laws or rules of any kind, they may
plausibly as wholes make a contribution to our decisions, because we can
respond to them.
There
are of course unconscious computational processes of our brains that do engage
with constituent features of what we experience, and/or representations of them
in terms of types and mathematical variables; and these processes are essential
to our having conscious experiences at all, and are essential in other ways to
the determination of our decisions and actions. But I suggest there is in addition, in our conscious
decision-making and action, a contribution from our response to the grasping in
our conscious experiences of whole combinations of features; and since this
response cannot be determined by laws or rules, it is not one that could be
achieved by non-conscious information-processing.
My suggestion is that the capacity to respond in this way to particular
and perhaps unique combinations of circumstances is advantageous, even though
it must also be fallible because its reliability is not assured by any rules or
laws. This advantage explains why
consciousness has been promoted by evolutionary processes.
An example I sometimes give
is that of George Gershwin composing his melody ‘The Man I Love’. This melody
has general and quantitative features in common with other melodies; and these
features, being general and quantitative, can engage with general rules, so
that the melody can readily be identified by application of computational
rules. No doubt such an appealing
melody has constituent features that can push buttons in our emotional make-up
that have been established by evolution and environment. But the way this melody sounds, and
even the way some two- and four-bar chunks of it sound, is unique to this
melody; and the experience of such a unique melody or chunk of melody, as a
whole, is an example of what I mean by a gestalt that cannot engage with laws
or rules.
When Gershwin was
composing the melody, possibilities for how it should proceed must have been
thrown up by unconscious processes. But
he must consciously have appraised these possibilities as he composed, in order
to decide whether to adopt them or modify them or look for other possibilities;
and ultimately he must have consciously appraised the melody itself, in order
to decide whether to assent to it as his composition or to refine it further;
and I suggest that, in appraising the possibilities and the melody, Gershwin
was responding to gestalts of the possibilities and of the melody and/or chunks
of it, which because of their uniqueness and feature-richness could not engage
as wholes with pre-existing rules of any kind.
The same argument
applies with even greater force to the creation of ground-breaking works that
defy existing aesthetic standards, such as Wagner’s Tristan und Isolde
or Picasso’s Les Demoiselles d’Avignon.
The creation of works like these requires aesthetic judgments to be made
by the creator of the work, which must take account of whole gestalts that
could not engage with pre-existing laws or rules of any kind.
I suggest that
the argument also applies to human decision-making generally, whenever we take
account of whole feature-rich gestalt experiences in shaping our decisions and
actions.
I can’t explain how
we can respond to gestalts in ways not determined by rules – this would require
a far greater understanding of consciousness than is available at present – but
that we can do so is supported by the very fact that we do experience whole
feature-rich gestalts ‘all-at-once’, and by many other reasons. Here are a few.
Any
decision or action that can be determined by the operation of general rules on
existing circumstances can be determined by computation, without
consciousness: this seems obvious, and
it is confirmed by Alan Turing’s arguments, and by the existence and
performance of computers. Our brains do
undoubtedly have a prodigious capacity for unconscious computations. Think for example of the computations necessary
to give us three-dimensional vision, with stability of viewed scenes despite
voluntary movements of head and eyes, or those necessary to enable us to
balance and to catch balls. Though most
of us can’t plug directly into this computing power, there are reports of
people who have done so, not necessarily to their advantage: in his book The Man Who Mistook His Wife
For a Hat, for example, Oliver Sachs wrote about autistic twins who enjoyed
exchanging multi digit prime numbers.
If optimal decisions could be made by computations alone, why do we have
our clumsy fallible conscious processes at all?
The
fact is we are so constituted that, particularly when we are faced with a novel
situation requiring some significant decision or action, conscious experoences
are heavily involved in our decisions and actions. Much unconscious information processing seems to be finely tuned
to support conscious experiences in which currently important information is
presented simply and vividly, in the manner of an executive summary prepared
for a decision-maker in business or government. The computer scientist Marvin Minsky once dismissed consciousness
as an imperfect summary of what is going on in the brain; but he failed to
recognize that there must be an evolutionary advantage in having this
summary. Surely, we have these
executive summaries just because we can respond to them in ways not available
to unconscious computation; that is, in ways not determined by laws or rules.
One
important way in which I contend we use and respond to gestalt experiences is
in plausible reasoning. Most human
reasoning is not algorithmic: that is,
it does not (overtly at least) proceed in accordance with rules of logic and/or
mathematics and/or probability, or any other rules that could be incorporated
into a computer program. Rather, it is
informal plausible reasoning, in which the premisses or data do not entail the
conclusions by virtue of applicable rules, but rather support them as a matter
of reasonable judgment. Arguments of
Hume, Popper and others, particularly as developed by the American philosopher
Hilary Putnam, show that plausible reasoning cannot be fully explained in terms
of rules for good reasoning, whether they be rules of logic or mathematics or
probability or whatever.
Consistently with this, consciously held reasons for decisions and
actions are often inconclusive, and there is an apparent gap between reasons on
the one hand and decisions and actions on the other. Hume said we always act in accordance with the preponderance of
our desires. But that assumes that
desires, like forces in Newtonian physics, are commensurable, so that there is
always a single “resultant” desire that can direct our decisions and actions;
whereas in truth there is no common scale on which (say) a feeling of hunger
can be explicitly weighed against a feeling of obligation to carry out a
promised task. If desires conflict, the
outcome is not determined by any overt preponderance of one over the other
(because there can be no preponderance of incommensurables), but by plausible
reasoning to a decision that takes account of their different characters. In this plausible reasoning we use and
respond to gestalt experiences.
Of
course plausible reasoning is fallible and, as Daniel Kahneman, Amos Tversky
and others have shown, it is affected by unconscious biases. But plausible reasoning is indispensable,
and biases can be addressed and their effect minimized only by careful conscious
appreciation of them, that is, by plausible reasoning –certainly not by leaving
it to the unconscious computational processes that are the source of the
biases.
My proposal thus offers an explanation
why conscious experiences enable us to live more successfully than if our
decisions and actions were determined by unconscious processes alone. It gives a function to the three most
striking puzzles about conscious experiences, subjectivity, qualia and
unity. And as I have argued elsewhere,
it also opens the way to a robust account of free will and responsibility.
It’s been put to me that my proposal is courageous, in
the Yes Minister sense, in that by suggesting that the physical world is
open to non-physical influences, it conflicts with well-established
science. Well, it does conflict with
Newtonian physics, as interpreted by Pierre Laplace. But science has moved on since then. The world is probably indeterministic; and while quantum
mechanics supports randomness rather than indeterministic choice, it plainly
leaves it open that physical events may be affected by conscious experiences
and choices.
These are large and difficult questions,
and I cannot explore them here. What I
do say is that the reasons supporting my proposal are strong, and the correct
understanding of fundamental science is unclear. If conscious experiences are truly efficacious, as I suggest they
must be, the reasons for thinking they have this efficacy only by virtue of
physical processes and physical laws are not compelling. Thus my proposal is a plausible one, indeed
so far as I’m aware the only plausible proposal there is for assigning a
specific role for conscious experiences that could not be performed by
unconscious processes.
Has anyone got a better suggestion?
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