But then, I tend to accept that self might be a complete illusion, despite the experience. And free will. To the point that I'm ok with saying that they may not even exist, even though they are experienced. So I'm not going to close the door on saying qualia do not exist, even if at this point it sounds ridiculous.
What could it possibly mean to say that it's possible to experience something that doesn't exist?
Thomas Reid asked similar questions of Hume and Berkeley's work, but nobody listened to Read, because he took all the fun out of everything.
Here's the rub.
Dennett, following Wittgenstein, is quite clear that we never communicate anything with a phenomenal character, only our judgements about that phenomenal character. If we could directly communicate the phenomenal character of things, then there would be no problem of other minds.
What Dennett is up to here, and which he finishes off in Consciousness Explained, is demonstrating over and over again that how things seem to us is a dreadful guide to how they are. Ultimately, his final argument will be that all we have is our judgements about phenomenal character and that there simply isn't any available determinate content below those judgements. That's not to say that the judgements are not judgements of something: they are the words produced by a brain that is doing a lot of measuring, judging and so on (The Easy Problem) just without phenomenal character and thus producing statements that are rooted in the underlying workings of the brain, but just the first time these become both public and determinate. Dennett's point is that it would be really easy to mistake these judgements for something more *ahem* mystical like real intrinsic qualia.
By piling up lots of examples of how our seemings are sometimes both merely indefeasible and clearly not intrinsic, not accurate and apparently poorly connected to any underlying neural reality, Dennett hopes to cause an 'aha' moment at which you realise that all this talk of the undeniability of the mental is just one last parlour trick from Descartes that we can let go of. All there is is the judgement and that is more than real enough to fool us into making more extravagant assumptions.
He's acutely aware, pace Wittgenstein, that there's no logical argument that will do the job here. Once again, I have explained why lots of times before. Here's one example from back at SC:
Me a while back said:
The private language argument is explicitly and specifically concerned with the possibility of a logically private language, that is a language that no other person could possibly learn.
As in:
a language that describes my inner experiences and that only I myself can understand
(PI 256)
The PLI is really an attack on the classical empiricist model of language acquisition, on the claim that one can talk privately about qualia in the same way as you can publicly talk about other things. The whole point of the PLA is to make the point that a truly logically private language is logically impossible and thus that qualia, which are private, are, depending on who you follow, either real yet beyond language or not real at all.
Any conceptualised state that expresses a proposition, you know, the belief that P, for example, is and must be, on Wittgenstein's (and any other analytic account I'm aware of) logically public because another can learn a word's use by spotting correlations between use, behaviour and the world.
Qualia, of course, are not public.
Dennett goes to a great deal of trouble to make it clear that any pre conceptualised content is underdetermined and open to revision on the fly. He illegitimately extends this to the claim that there is no determinate content. And well he might, because he's acutely aware that any determinate content prior to conceptualisation is wide open to being a candidate for being the vehicle for qualia.
Personally I accuse Dennett of making a different Cartesian materialist error: he assumes that the mental and the physical are not the same thing. This is, to my mind the oddest of post dualist errors as the simplest explanation of all is simply that mental states are public,
as physical states. The only reason that this isn't immediately obvious to all is that the the mental aspects of these physical states only occur inside a living brain. The issue is further confused by the fact of all the intentional judging going on and if you split the bits that Dennett wants to get rid of - the feel of the biological with the bits Churchland wants to get rid of, the intentional redescription of folk psychology, you are left with two separate aspects of the mind that most theorists spend their time being confused about.
Intentionality (as in the intentional stance, Folk psychology, Propositional attitude talk and so on) is a pre-scientific theory of mental content that would be ripe for elimination if we hadn't come, in the last ten thousand years, to base our entire self conception upon it. Qualia are a hopelessly confused attempt to understand the simple and not terribly surprising fact that internal processing involving a lot of fast binding and a really robust user illusion just happens to feel like something from the inside as well as look like something from the outside. They are wide open to reduction to the biology once we get past the idea that the mental is somehow not identical to the physical.
From the biology, the intentional looks like so much fantasy. From the intentional the products of the biology look like a private fiction. Both are half right and half wrong. Dennett knows this is a possibility, if for no other reason than that we argued each other to a standstill in the bar at the Royal Society in the early nineties. But he reads Wittgenstein as denying qualia where I read him as denying the possibility of talking about them. There's not much movement available there.
You want a fast anecdote to this paper: imagine that the whole paper was diagnosing the easy problem. Suddenly it looks like both a lot of waffle and making assertions that have determinate answers in the biology: we know what happens when we put on inverting glasses and the image eventually reverts. Now we just add the rider that feels like something to be bound within a living brain. The easy problem and the hard problem just are not that dissimilar.