One and a half
answers - reality.
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Reader beware! While most
of the material on this site deals with leading or at least,
recognised theories, this is where I get to tell you straight out
what I personally think.
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The appeal of the doctrine of qualia
(and it is considerable) stems from the powerful intuitive sense we have
that something is missing from our accounts of, say, seeing a
distant light. The physical
business of light striking our retina and the brain responding is all very
well, but however good our account of the physics and the biology, they
never explain what it is like to see the light. It seems perfectly
possible to imagine all those physical processes could happen, and I could
come to know that there was a light over there, without my ever actually
seeing the light – perhaps
rather in the way that blindsight seems to work.
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There is, of course, something
missing from our theories about sight and other senses, but it is not a
further bit of explanation or some additional data – it is simply the
reality of actually seeing a light. Even the
most comprehensive theoretical account of light does not, itself, contain
real light, and when we put it like that it’s obvious that we shouldn’t
expect it to. Knowing what something is like is not, in fact, a matter of
knowing anything in the sense of having some information about it; it is a
matter of having, or remembering, a real experience.
Why don’t people see, or
accept this point? I think there is a group of wrong but very prevalent
ideas which obscure the truth in this
area.
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One is the theory, widely accepted
within philosophy for a long time, according to which we don’t see real
objects, we see sense-data about objects. This theory was based on
consideration of illusions. If we saw a mirage in the desert, there was no
real oasis, so we couldn’t be seeing one: yet we seemed to be seeing
something. It must be a mental image of an oasis, or something of
that kind, that we were actually seeing. Since illusions and reality could
be indistinguishable, it seemed to follow naturally that even when there
was an oasis, it was really only the sense-data we perceived directly. The
theory was undoubtedly made more plausible by our understanding of the
physiology of vision, which told us there were a number of data-processing
steps between us and the perceived object. First light reaches our eye: it
is focused on the retina; it evokes a response in the rods and cones
within the retina; it becomes a set of neural impulses; it travels to the
back of the brain along a set of neural pathways and then… at some stage
it impinges on our consciousness. Surely by the time the signal got to
that point, we were dealing merely with data; ergo, data was all we ever
really perceived. |
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Of course, this is entirely wrong. In
the case of illusions, the mistake does not come between us and the thing
perceived (if any); it comes afterwards, in our interpretation of what we
are perceiving. We don’t correctly perceive mistaken data about an oasis,
we mistakenly believe we see an oasis. When we see a real thing, we see
the thing: the physiological story about eyes and nerves is simply about
how we do it.
Nevertheless, the sense-data
perspective exerts a powerful influence. If data are all we experience,
and we have all the data about a colour or sensation, what could possibly
be missing? |
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A second common mistake is to assume,
consciously or not, that information is all there is to reality. We
tend to think of Nature enforcing laws and doing the calculations to
decide how objects should move and interact. In doing so, we fall into the
trap of confusing the maths and the theories we use to describe
reality, with an underlying principle which generates reality. There is no such principle, of
course, only real things themselves. Knowledge may in some sense be power,
but to have all possible knowledge about something is not actually to
have the thing itself.
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This is easier to see in certain cases
than in others. No-one imagines a cricket ball is actually doing
sums as it flies along in order to determine its own path. But when it comes to astronomy,
the feeling that maths is somehow in control becomes overwhelming: the
relevant calculations must, we feel, in some sense, perhaps only implicitly, be going on somewhere, perhaps in a
Platonic second world. We start imagining that to understand cosmic maths
is to ‘know the mind of God’. But of course, maths and theories are purely
descriptive and purely human. God would no more need maths to understand
the world than he would need a telescope. Reality is not constituted by
data, but again, if we think it is, and we have all the data about
redness, how come we don't experience
redness?
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Which leads on to a third issue – what
does constitute reality? If real things don’t consist of data, what
do they consist of? What is it that caused them to exist, and be
the way they are? Here we touch on the final important element in the
mistaken mystery of qualia. Among the deepest and hardest questions of
philosophy or science are ‘why is there anything’ and ‘given that there’s
something, why this?’.
These questions are particularly hard to deal with
because it isn’t at all clear what kind of answer there could possibly be.
However, if we could reduce the world to formulae, there might be more of
a chance. Philosophers and scientists have all, I suspect, at some stage in
their life nurtured a secret dream of finding the theorem, the
proof, the calculation, which explains everything: which makes it
possible to calculate the nature of the world from nothing, and hence,
implicitly, to show that the world was impelled into existence and shaped
into the incomprehensibly complex patterns it assumes today, by logical,
mathematical necessity. In philosophy this unacknowledged project took a
severe, perhaps fatal blow with the failure of Frege’s project to
reduce maths to logic. If maths can’t be boiled down to pure logic, there’s
no point in even thinking about physics. But in physics itself the dream
lives on. We rightly expect calculation to explain reality to the
extent that explanation means 'illuminating description'; and we slip easily into
the unreasonable expectation that calculation can be the explanation of reality
in the sense of having caused it.
So there is, at the end of
the day, a mystery here. But it isn’t the mystery of qualia, which are
just real experiences. It’s the mystery of reality
itself.
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