You expect that I will reject every description you could offer, but you haven't actually tried any. If you did try a few descriptions and I did find something wrong with each of them (which is not unlikely), your arguments would look a lot more serious.
There is a reason I expect that. Namely, you criticized a proposed definition on the grounds that it was "synonymous" with consciousness. But that's exactly what it was supposed to be: we are talking about consciousness, not something else. So any definition I propose is going to be synonymous or extremely close to that; otherwise I would not propose it.
But now I can only assume that you simply can't think of any such descriptions.
Your assumption is false. Let's say "personal perception." Obviously I can anticipate your criticism, just as I said above.
All descriptions are incomplete. You just have to provide a description that matches bananas better than it matches apples or sausages. A malicious adversary can always construct some object which would match your description without really being a banana, but at some point the construction will have to be so long and bizarre and the difference so small that we can disregard it.
If your description of a banana does not suggest that it is fruit, your description will be extremely incomplete, not just a little incomplete. In the same way, if a description of consciousness does not imply that it is subjective, it will be extremely incomplete.
Again, all descriptions are incomplete. "What makes someone say ouch" is quite accurate considering it's length.
The point is that you are ignoring what is obviously central to the idea of pain, which is the way it feels.
So any definition I propose is going to be synonymous or extremely close to that; otherwise I would not propose it.
Again you confirm that you don't understand what the game taboo is (rationalist or not). "Yellow bent fruit" is not a synonym of "banana".
"personal perception."
My criticism is that this description obviously matches a roomba. It can definitely perceive walls (it can become aware of them through sensors) and I don't see why this perception wouldn't be personal (it happens completely withing the roomba), alth...
(This post grew out of an old conversation with Wei Dai.)
Imagine a person sitting in a room, communicating with the outside world through a terminal. Further imagine that the person knows some secret fact (e.g. that the Moon landings were a hoax), but is absolutely committed to never revealing their knowledge of it in any way.
Can you, by observing the input-output behavior of the system, distinguish it from a person who doesn't know the secret, or knows some other secret instead?
Clearly the only reasonable answer is "no, not in general".
Now imagine a person in the same situation, claiming to possess some mental skill that's hard for you to verify (e.g. visualizing four-dimensional objects in their mind's eye). Can you, by observing the input-output behavior, distinguish it from someone who is lying about having the skill, but has a good grasp of four-dimensional math otherwise?
Again, clearly, the only reasonable answer is "not in general".
Now imagine a sealed box that behaves exactly like a human, dutifully saying things like "I'm conscious", "I experience red" and so on. Moreover, you know from trustworthy sources that the box was built by scanning a human brain, and then optimizing the resulting program to use less CPU and memory (preserving the same input-output behavior). Would you be willing to trust that the box is in fact conscious, and has the same internal experiences as the human brain it was created from?
A philosopher believing in computationalism would emphatically say yes. But considering the examples above, I would say I'm not sure! Not at all!