Win,
Yes. But the issue isn't whether I am a p-zombie. The issue is whether you are.
No, the issue is why is P-Zombie Win (pWin) so sure he's not a P-Zombie.
The evidence doesn't come from what I tell you. Whether I am a p-zombie or not is irrelevant.
Win to loki:
"The only evidence you'll ever have for the existence of phenomenal consciousness is your own. It is correct".
Win to pLoki
"The only evidence you'll ever have for the existence of phenomenal consciousness is your own. It is, unfortuantely, not correct".
Because the qualia themselves are still left unexplained. And each of us knows that they exist.
Yes, including pWin! He knows, just as well as you and I, that he has these qualia. Except he doesn't...
...and there is a qualitative difference between your experience and your p-zombie twin's experience, or rather lack of it
If I ask pWin (who doesn't know he's a P-Zombie) "is there a qualitative difference between your experience and your p-zombie twin" he will answer "yes, because the p-zombie doesn't have the same direct access I have - he's missing the 'quality' that I have access to". Now, you and I both snicker behind his back, because we know that poor old pWin is deluding himself - although he thinks and says he has this 'quality' aspect to his experiences, we know he doesn't.
Still, for me the question remains how can he talk so assertively (and honestly - by definition, he's not lying, unless you are also lying - after all, he's an exact replica of you!) about his direct access if he doesn't have it? And if he can be so completely fooled into believing that he has it, then why can't I be? You seem to be saying "you are correct to trust your own perception", and also "a P-Zombie is wrong to trust his own perception". Why the difference, unless you are just starting from the assumption that there is a difference (even if you can't explain the difference)?
Let me mix your thought experiments a little. We have a "DupliZombifier". I strap Win into the 'in' chair in room A. In rooms B and C we have 'out' chairs. I throw the switch, and instantly I get a 'true' copy of Win in one 'out' chair, and a p-Zombie copy of Win in the other 'out' chair (as a small offering to AmateurScientist, lets just say that the Win in the 'in' chair is vaporised after a moment (or two) of excruiciating pain - sorry Win, but I'm playing to the audience here and it's my thought experiment, okay?). Anyway, the DupliZombifier also includes a randomizer, so no one knows which room (B or C) contains the p-zombie.
So we sit down to interview our two potential Wins. Both answer the same to any question regarding qualia, direct access, and 'evidence'. Neither is lying. Both are at pains to express the 'quality' of their direct access. Both deny that it could be some sort of illusion. "I know what you're getting at", they both cry in stereo, "but you're wrong - I can assure you I'm not the p-zombie. Although I can't prove it to you, I have only to 'look within' to see that I do indeed have this extra 'experience' that marks me as the non-zombie." Of course, at least one of them is wrong. Why is it not possible they are both wrong?