The problem with philosophical zombies ("p-zombies") is that, since they're indistinguishable from normal humans, some of them must go around talking about qualia and consciousness and so on; it's mysterious what's causing them to do this, since they don't actually have any qualia or consciousness.
This is the strongest argument that mind is matter: mental things like qualia clearly do cause physical events (e.g. discussions about qualia), which seems to suggest that qualia etc are themselves physical, since we expect physical events to have physical causes.
(And yet I can't stop wondering how being a collection of atoms feels like anything.)
I've never understood why that's an argument, or why talking about qualia and consciousness depends on having them, any more than a program that prints "ouch" when you stop it feels real pain.
To me, there just seems to be an undecidable knot there that can never go away, even if you say it doesn't exist like Dennett and others.
Another thing that never gets said is that questions of consciouness are really questions about solipsism in disguise. The real question isn't whether what it's like to be my neighbour is different than what it's like to be someone who died 100 years ago. The only real "obvservable" difference is that it's like something else to be me.
"I've never understood [...] why talking about qualia and consciousness depends on having them"
It doesn't, but someone has to have them in order for the concepts to get introduced in the first place.
Imagine a world that has always been populated entirely by p-zombies. By definition, that world should be indistinguishable from this world, so how on earth did they get started talking about consciousness and qualia?
In your example of the "ouch" printing program, someone had to have pain and say "ouch" before such a program was made.
Imagine a world that has always been populated entirely by p-zombies. By definition, that world should be indistinguishable from this world, so how on earth did they get started talking about consciousness and qualia?
The answer to the question "how did they get started talking about qualia" is: by definition, the hypothetical Z-world is indistinguishable from ours. In our world, people talk about qualia. Therefore, in the Z-world, zombies talk about qualia. What's more, the beginning of "zombies talking about qualia" would be the same as the beginning of "people talking about qualia".
I have a feeling I'm misunderstanding you.
In your example of the "ouch" printing program, someone had to have pain and say "ouch" before such a program was made.
Why? What if the program is the output of a random number generator? Does that mean the random number generator experiences pain?
The answer to the question "how did they get started talking about qualia" is: by definition, the hypothetical Z-world is indistinguishable from ours. In our world, people talk about qualia. Therefore, in the Z-world, zombies talk about qualia.
Right. Which implies that the reason that we talk about qualia is not that we have them (otherwise zombies wouldn't), but for some completely different reason that just happens to exactly line up with the qualia that we in fact do have. That would be an astounding coincidence and is a major strike against the theory per Occam's Razor.
Actually, it just seems a completely empty argument that merely assumes it's conclusion.
Y's are exactly like human in every physical respect but they don't have Z. Therefore Z is not physical and since we're vacuously assuming Z, human must have something besides physical qualities.
This is the strongest argument that mind is matter: mental things like qualia clearly do cause physical events (e.g. discussions about qualia), which seems to suggest that qualia etc are themselves physical, since we expect physical events to have physical causes.
(And yet I can't stop wondering how being a collection of atoms feels like anything.)