Consider two fundamental distinctions:
Real vs. Unreal – In the space of all possible worlds, only one is the “real” world; the rest are unreal. Or if you prefer, among all mathematical structures, only some describe real things; the rest are only abstract math things.
Feel vs. Unfeel – Many think they can imagine physical objects just like our brains, except that those brains do not have an associated internal life, i.e., feeling or experience or consciousness.
Once can deny each of these distinctions. Some claim that all math objects are equally real, or that all possible worlds are just as real. Others say all physical objects with the right info processes must experience.
While both these concepts seem to me reasonably understandable, it isn’t obvious to me that they are distinct concepts – maybe they are the same concept. That is, I’m not sure it makes senses to talk about unconscious but real physical brains, or conscious but unreal brains. Maybe what it should mean for a world to be real is that its brains, at least of the right sort, really do feel.
Added: To clarify, it is not clear it makes sense to posit a real world made of parts which could never be conscious, no matter how they were arranged. Actually assuming a conducive arrangement is not required.
you either make the leap past the demon to believe in an external world, or you don't and all you're left with is your experience (with no basis to assess whether it correlates to anything, has any meaning, etc.). once you believe in science -- and it's a matter of belief as much as religion -- then the tree makes noise even when no one's around. that leaves imaginary worlds as nothing more than internal brain states, language games, etc.
as for zombies, i love the idiocy of assuming something could be configured just like us, but not have whatever consciousness is. what's the basis for assuming the existence of this extra special secret sauce called consciousness, rather than just assuming it's how it feels to have a brain arranged this way, operating this way, etc. people playing zombie games have this weird quasi-religious need to assert we're magic in some way, rather than just matter like any other. (once you believe in science, the need for an observe to make the world real similarly seems silly (yes, i know about the silly anthro quantum theories, etc.).)
bonus: if you believe in evolution, it's silly to posit that we're the only one's with consciousness, and that it doesn't arise naturally out of a certain kind of brain structure. given that evolution explains how we developed, and from what, and how much we have in common with those things, occam again requires we assume it's pretty much all the same throughout the closely related mammals. (so dumb every time people are amazed animals use tools, or language, or mirrors, or etc.)
@Asher
We’re just seeing problems of language and incompleteness in human ability to understand the entirety of existence.
I once suggested, to a person who had given a short talk on free will, that perhaps the semantic shift from causation to effection (actually I said effectation) might help. Does it? I mean, we have affection, why not effection? I think actually that’s probably a good thing – affection is key here.