Chalmers's motivation to make his conceivability argument comes from some kind of incorrigable introspection. But the details are unclear to me.
I think there is a way that the belief in phenomenal consciousness is similar to the idea of a testimony and a way it is different.
Different:
Qualia are "one dimensional". They don't need to represent anything. So if I "see red" there need not be any red objects. That property is in fact why they are incorrigable. A testimony though, is suppose to represent the church being true, and junk like that. So testimonies try to buy more than folks who "take consciousness seriously".
Similar:
Now it is interesting you bring this up because a while ago I had a similar thought. Damn, it appears somehow I can't copy and paste from my own blog:
http://worldlyliving.wordpress.com/2007 ... d-seeming/
Paragraphs 3,4,5 are the important ones. This fleshes out why I said earlier that I'm not clear on his position of introspection. It's one thing for Chalmers to believe he has conscious life, it's another thing to give a detailed account of that life. And to me that's a big problem. It's one thing for him to say that qualia are by definition unmistakable, and another to accurately recount when he had an experience. Bringing to mind experiments in cognitive science which show that we often can't possibly experience what we think we experience. And that leaves open the possibility for (not again!) radical skepticism where it's hard to see how any consciousness can be incorrigable.
So now the link to a testimony. A testimony is ineffable and incorrigable. If someone says they've got one, then, by golly, they've got one. And there is no point in trying to match up mine to yours (think inverted spectrum here). So I can see your point for inconsistency. Because a testimony is in fact an experience (as TBMs will tell you) and experience is incorrigable. Given my sentiments above, it's hard to see how someone in Chalmers's position can draw the line and say a testimony, which TBMS report as experiential, cannot or might very well not be something they really experienced. If we can draw the line there, why can't we question some of the things Chalmers claims he experience? What makes him more of an expert on his experience than a TBM is on theirs? But if we can question anything in Chalmers's experience, then why can't we question everything? Ultimately, seeing red wouldn't be off limits I don't think, and if you go that far, then we're cutting deep into his generalized set of "conscious experience" which Chalmers draws on and ultimately, one starts wondering if maybe he himself could be the phenomenal zombie twin.
Now Tarski, stay with me, I know this is a long post. This has been an important issue for me long before I ever read Dennett. Many skeptics are content with believing that a Mormon testimony, a burning in the bosom, or whatever, is something like seeing a mirage or duping ourselves into a hallucination. The experience happens, but it doesn't refer to anything significant. But that's not good enough for me. When I was missionary, I not only had a hard time believing that Elder Green's experience while reading and praying about the Book of Mormon tells us anything about his knowledge,
but I couldn't believe in 98 percent of the cases that anyone was having testimony experiences at all. I think something "Orwellian" was going on as soon as those guys manned the pulpit, or possibly even during those times where they were supposidly feeling spiritual. Most of the time, I don't think it's a case that by stressing over their testimony, Elders would trigger the hallucination, but rather, given enough time doing what BKP tells us to do, and bear what we don't have, our psychological consciousness constructs a narrative that we might thoroughly believe yet it never had anything to do with actual experience! I'm not sure if I'm thoroughly convinced by Dennett, there are other strong positions in phil mind worth considering, but one thing is for sure, you can call me a "testimony experience eliminativist". I don't just doubt the testimony's legitimacy, I doubt that warm fuzzies of any significance even happen most of the time or even make any sense.