How Not to Imagine Zombies

I don’t follow, honestly, why Richard is so committed to the claim that the zombie case is an argument at all. It’s clearly an intuition pump, rather like the direction of fit metaphor over in the philosophy of action/reasons for action literature, or Frankfurt-style examples. If you have the intuition, you’ll find the case congenial; if you don’t, you’ll find it silly. What matters, surely, is whether there is some independent reason to suppose zombies are actual, or at least genuinely possible (rather than logically possible). If it turned out, say, that cats were zombies, and we could somehow prove this, then we’d have an argument. As is, the zombie notion, all on its own, seems to do no work. What has to do the work is something like the question-begging assumption, which you note, that the physical world cannot fully account for consciousness.

Well, there may not be a contradiction; that depends on what we find out. Put it this way. To me, we seem to be in the same position as someone in 1700 wondering if it is possible that *that stuff* (pointing at some water) is made out of H20 or some other stuff. It seems possible that *that stuff* could be made out of all sorts of other stuff besides H2O, but since what is actually being demonstrated is in fact H2O, those seemingly possible scenerios are not in fact really possible. When we try to imagin a creature that is physically identical to me in every way except that it lacks consciousness we may be in the same position. My point is that this is an empirical question not an a priori one in the fullest sense that RC wants. So there may be a couple of routes to the contradiction (some I mention in the post The Inconceivability of Zombies)

Hang on; I think you’ve changed subjects on me. The issue was whether the existence of zombies is logically possible, not whether they are actually possible. I accept that the latter has to be demonstrated (empirically): we’d need to find an uncontroversially physically identical (to us) creature that we could somehow determine lacked phenomenal consciousness. I’m on board with that.

What I’m wondering about, though, is why go so far as to deny the logical possibility of zombies. They certainly seem logically possible. It also seems to me that it’s logically possible that water was not H2O. In some other world with different physical laws, something that had all the properties we associate with water could, nonetheless, turn out to chemically be XYZ rather than H2O. That is not the actual world, ex hypothesi, but I don’t see why it isn’t a possible world. We can repeat this for zombies fairly easily.

I suspect the reason that the XYZ/H2O case seems to not be logically possible is that the referent of “water” has already been fixed in the actual world as being H2O. So, when we play the possible worlds game, there’s probably a covert switch of reference-fixing going on. That is, rather than “water is XYZ”, what we actually imagine is something like “a substance qualitatively identical to water is chemically identical to XYZ”.

In the case of zombies, though, whether and how the referents of terms such as “mind” (and “belief” and “desire” and all that good stuff) are fixed is exactly the issue. So, while I agree that the zombie case itself does no argumentative work, I’m not seeing why we have any basis to deny its logical possibility. It looks to me like, pending a successful completion of a reductionist or eliminativist or emergentist program — or any other such materialist relation between mind and body/brain — we don’t have any good reasons to rule out the possibility that a dualist story is true, i.e., that we don’t live in a materialist world.

I think I addressed that; I suppose I didn’t do a very good job!

Suppose we didn’t know what water was, chemically. There’s this stuff in rivers, we drink it, wash in it, and so on — it does what water does. Until we do the chemical analysis, it’s an open question what actual chemical fixes the referent of the term “water”, right? It could be H2O, it could be XYZ. Once we do the chemical analysis and determine water = H2O, then what follows is that any possible world like Twin Earth is not a world where water = XYZ but a world where something very like water = XYZ.

But, moving to the zombie case, we’re in an epistemic situation comparable to that of those poor unfortunates who existed before the chemical analysis of water was completed. We don’t really know what the referents of terms like “mind”, “belief”, “desire” and so on are, except in terms of similarly-loaded intentional vocabulary (e.g., a belief is a certain kind of propositional attitude such that…). So, until we either finally do the full physical analysis of consciousness, or find out no such analysis is possible, zombies are still logically possible. The world where there are physically identical creatures to us that lack phenomenal consciousness could be this one. As I’ve said elsewhere, since all the zombie case does is point out this is a possibility, it’s really not that interesting. Lots of things could be; I’m more interested in what actually is, which requires either doing the afore-mentioned analysis or showing it can’t happen. But, at the least, I think we need to concede that, right now, zombies are still logically possible.

(This assumes, of course, that mental terms rigidly designate, which I’m not sure about. (Unlike “water”.) But that’s a whole ‘nother issue.)

I would agree that we’re getting tripped up on what constitutes a logical possibility. As I’m reading it, something is logically possible if we don’t know enough to find a contradiction. So, “water is XYZ” is not logically possible because we know enough about chemistry to say that the thing we mean when we say “water” is the very same thing we mean when we say “H2O”. However, “consciousness is not a physical phenomenon” is, I would say, still logically possible because we don’t know enough to determine that it’s a contradiction. That is, we’re not sufficiently clear on what the “physical phenomenon” is (nor, really, on what consciousness is) to determine that we’re not in a zombie world.

The issue with the zombie world, of course, is not to deny that phenomenal consciousness — by which I do just mean the subjective experience of “stuff going on in the head” — exists, but that it doesn’t follow from a certain kind of physical construction. So, the existence of zombies wouldn’t imply there was no consciousness, just that some creatures, physically identical to conscious creatures, nonetheless lacked consciousness.