Michelle asked:

What do philosophers understand by the term 'qualia' in relation to the mind-body problem and the
subjective character experience?

============

'Qualia' (the plural of 'quale', pronounced 'kwar-lay') is the name invented for something which is
alleged to exist, the incommunicable subjective character of conscious experience conceived as an
object of knowledge of the unique individual whose experience it is.

I say 'alleged' to exist, because I don't believe that qualia do exist. In my view (not all philosophers
would agree with me) qualia fall into the same category as vital force, phlogiston and the philosophers
stone.

Before we get into exactly what qualia are, or are thought to be, or how the idea of qualia impacts on
the mind-body problem, we can defuse one powerful motive for embracing the idea of a species of
object that is capable of being known by one unique individual, and by no other:

It seems overwhelmingly likely that the nature of brain states is such that information is encoded — a
better term would be encrypted— in a manner that renders that information incapable of being
directly accessed by any person other than the subject whose brain it is. I will not try to argue that
here. What this means is that there is a perfectly good sense in which only I can know what it's like to
be feeling this pain, or to be experiencing the genesis of this philosophical idea, or remembering
when... . Of course, these things can be put into words. I have just done so. But words only go so far.
Try describing a sunset to someone who can't see it. The difference is that the sunset is out there for
all to see, whereas my conscious states are in me. I cannot show them to you, I can only tell you what
they are 'like'.

The difference between qualia and subjective states as ordinarily conceived is that the occurrence of
a quale is only contingentlyrelated to the world outside the subject's mind. We could both be
experiencing the thing we call 'sky blue' or the thing we call 'feeling giddy', and the object that came
into my mind when I looked up at the sky, or when I stepped off the roundabout could be totally
different from the object in your mind. As I remember thinking when I was a child, 'what I see as blue
others might see as red and vice versa, and we would never know'. Or, better still, since you and I are
physically different, consider a precise cell for cell, proton for proton copy of you on Twin Earth. When
you and your 'doppelganger' look up at identical blue skies, there is no implication that your quale of
blue is the same 'colour' as your doppelganger's quale of blue.

This thought experiment can be taken one step further, as a refutation of the materialist view of the
person. Your doppelganger might not have any qualia at all.So far as your doppelganger was
concerned, all might be darkness inside. Physically you are identical. You walk the same walk, talk
the same talk. But you are a subject of experience while your doppelganger is a mere zombie.

(Incidentally, there is a hilarious cartoon of a 'Zombie with Qualia' at the foot of the Pathways launch
page by former Pathways student Glyn Hughes.)

As I said, I don't believe in qualia. I don't believe that there could be a physical 'zombie double' of me,
so I reject this ingenious argument for mind-body dualism. As Wittgenstein demonstrates brilliantly in
his destructive critique of the idea of a 'private language' in the Philosophical Investigations,we think
we are talking about objects of knowledge when in reality we are merely babbling.

Geoffrey Klempner