http://esr.ibiblio.org/?p=1192#more-1192
ADDED: Even if you disagree with ESR's take, and many will, this is the clearest definition I have seen on what qualia is. So it should present a useful starting point, even for those who strongly disagree, to argue from.
On the incommunicability of qualia:
First, I disagree that qualia are inherently incommunicable, they just always have been.
As children, we learn what a tree is when someone points to a tree and says, "tree". In this way, "what a tree is" is communicable.
Red is communicable too. However, what you experience when you experience redness has not been communicable, because it happens inside the brain. When someone says they observe something red, you can only assume that they have some experience analogous to your own experience.
But there's no reason why we can't observe the experience indirectly, eventually, as neuroscience develops. Hooked up to the right machine, it could indicate if I'm "experiencing redness", either because I'm observing something red or imagining something red.
No. This means that the label "tree" is communicable, and that with any luck, native ability to separate natural kinds will fill in what the label is meant to contain. The definition of "tree" is also communicable, but it doesn't involve pointing and isn't closely wedded to the internal mental understanding of treeness. (My mental understanding of treeness is something like "pl... (read more)