Chalmers argues for metaphysical possibility, not nomological possibility. He doesn't propose that zombies can actually exist in our universe with its unique laws of nature. To say that zombies are metaphysically possible is just to claim that they would be possible with a suitable fudging of natural laws. What this ultimately boils down to is logical coherence. If something is logically coherent, then it is metaphysically possible.Les Sleeth said:In the conceivability argument, for example, Chalmers begins with an assumption that if something is conceivable, it is possible.
You don't need certain kinds of experiences to raise doubt with the physicalist model. In principle, physicalism can't account for any kind of subjective experience. I do believe that experiencing certain extraordinary states of consciousness may make it more apparent why this is the case, but the core of the argument only really requires that an individual have some sort of subjective experience and then proceed from there.Likewise, as you will see in the consciousness model I am preparing, I’ve had, and studied others’ reports of, certain experiences that contradict a physicalistic model of consciousness; plus, physicalists have yet to demonstrate consciousness can be generated by something physical, such as a computer.
What I meant to say was that once we have a set of metaphysical models that are all consistent with the evidence, then the only way to further decide between them comes from logical considerations (logical consistency as well as concepts such as 'simplicity' and 'beauty' which qualify as sort of inductive extensions of principles already seen to exist in nature). 'First I should make it clear that critiquing the logic of any argument, theory, statement, etc. is always called for; and of course we must rely on reason to discuss and develop theories. But I would have to disagree that the only recourse for metaphysical debate/discussion is rationalism, although it’s true that that is how most people end up talking about metaphysics. As far as I’m concerned, if a metaphysical statement has no experience that supports/implies it, or if we have no way to search for the experience which would support/imply it, then it is a big waste of time to discuss it (other than giving one’s logic muscle a work out).
Physicalism, dualism, and monism are all consistent with the objective evidence. Only various forms of dualism and monism, however, are consistent with the subjective evidence (first person subjective experience). To this extent, I think the arguments I cited against physicalism do fit your criterion of being empirical, or not overly rationalistic, insofar as they reject physicalism precisely because it doesn't exhaustively describe consciousness as it is experienced from the first person view. If anything, the eliminativist physicalist arguments seem to be the ones falling under the 'overly rationalistic' category since proponents of these arguments tend to flatly deny the first-person evidence. If the first-person evidence is not taken into account, then it's really impossible to construct an argument against physicalism; so if one does launch an argument against physicalism, he must be considering the nature of subjective experience.
I think our disagreements on this point have just come down to definitions then. I consider knowledge to be a purely intentional property. According to this definition, if there is nothing for the knowledge to be about, then there can't be knowledge in the first place. I don't think the same can be said for subjective experience. I think you are just using knowledge and subjective experience interchangably.You are correct to characterize “generalized knowledge,” as I mean it, as “contentless subjective experience'” if by content you mean an “object” of thought or perception; I couldn’t disagree with calling it “pure consciousness” either.