PART 2:

I think you are contemplating a situation where we remove a person's consciousness, and yet his behavior (which includes talking about his consciousness) remains exactly the same. I argue that, if such a thing is possible, then consciousness is a null concept, since it has literally no effect on anything we could ever detect.

Yep. I believe that's Eliezer's argument (the "anti-zombie principle" I think it was called), and I agree. That's why I prefaced it with saying that my understanding of the universe would have to be pretty far off in order for my self-zombification to even be possible. So, given the highly improbable event that p-zombies are possible, I sure wouldn't want to become one! Ergo, my own qualia matter a great deal to me regardless of anyone else's ability to detect them.

As far as I understand, you agree with me with respect to Q, but disagree with respect to P. But then, you must necessarily believe that P is categorically different from Q, somehow... mustn't you ?

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I'm not sure what it would mean for me to agree in terms of Q but not P. I'm not quite sure what you're suggesting I'm saying. So maybe you're right, but I honestly don't know!

If you do believe this, then you must also believe that any model of consciousness that we could possibly build will work correctly for anyone other than yourself. This seems highly unlikely to me, however -- what makes you such an outlier ? You are a human like the rest of us, after all.

Mmm... I'm not saying that I, personally, am special. I'm saying that an experiencing subject is special from the point of view of the experiencing subject, precisely because P is not the same as Q. It so happens that I'm an experiencing subject, so from my point of view my perspective is extremely special.

Remember that science doesn't discover anything at all. Scientists do. Scientists explore natural phenomena and run experiments and experience the results and come to conclusions. So it's not that exploring Q would just happen and then a model emerges from the mist. Instead, people explore Q and people develop a model that people can see predicts their impressions of Q. That's what empiricism means!

I emphasize this because every description is always from some point of view. For most phenomena, we've found a way to take a point of view that doesn't make the difference between P and Q all that relevant. A passive-voice description of gravity seems to hold from both P and Q, for instance. But when we're trying to explore what makes P and Q different, we can't start by modulating their difference. We have to decide what the point of view we're taking is, and since part of what we're studying is the phenomenon of there being points of view in the first place, that decision is going to matter a lot.

And if you are not an outlier, and yet you believe that the model won't function for you, then you must believe that such a model cannot be built in principle (i.e., it won't function for anyone else, either), and yet I think you would deny this.

I think that if a model of Q fails to inform us about P, then it will fail for P regardless of whose perspective we take.

However, I suspect that a good model of Q will tell us pretty much everything about P. I just can't fathom at this point how it might do so.

As I see it, the only way to reconcile these contradictions is to reject the idea that P is categorically different from Q, and thus there's nothing special about your own qualia, and thus the problem consciousness isn't any harder than the problem of, say, unifying gravity with the other fundamental forces (which is pretty hard, admittedly).

Well, part of the problem is that we know P is categorically different than Q. Or rather, I know my P is categorically different than Q, and if Q is going to have any fidelity, everyone else will be under the same impression from their own points of view.

I can guarantee that any model that claims I don't have conscious experience is flat-out wrong. This is perhaps the only thing I'd be willing to say has a probability of 1 of being true. I might discover that I'm not experiencing what I thought I was, but the fact that I'm under the impression of seeing these words, for instance, is something for which I believe it is not possible even in principle to provide me evidence against. (Yes, I know how strong a claim that is. I suppose that since I'm open to having this perspective challenged, I should still assign a probability of less than 1 to it. But if anything deserves a probability of 1 of being true, I'd say the fact that there is P-type experience is it!)

However, I can't make a claim like that about Q. I'm certainly under the impression that my wife is conscious, but maybe she's not. Maybe she doesn't have P-type experience. I don't know how I could discover that, but if it were possible to discover it and it turned out that she were not conscious, I wouldn't view that as a contradiction in terms. It would just accent the difference between P-type experience and my impression of Q-type experience. Getting evidence for my wife not being conscious doesn't seem to violate what it means for something to be evidence the way "evidence" against my own consciousness would be.

I'm oversimplifying somewhat since consciousness almost certainly isn't a "yes" or "no" thing. Buddhists often claim that P-type consciousness can be made "more conscious" through mindfulness, and that once you've developed somewhat in that direction you'll be able to look back and consider your past self to not have been "truly" conscious. However, the point I'm trying to make here is that we actually start with the immediate fact that P is different than Q, and it's upon this foundation that empiricism is built. We can't then turn around and deny the difference from an empirical point of view!

However, in spirit I think I agree with you. I think we'll end up understanding P through Q. I don't see how since I don't see how to connect the two empirically even in principle. But science has surprised philosophers for three hundred years, so why stop now? :-D