I just noticed that the Stanford Encyclopedia of Philosophy entry on Zombies was recently updated (authored by Robert Kirk, who’s book I reviewed for phil. psych). I was pleased to see that my JCS paper was mentioned in the “anti-zombie argument for physicalism” section. But Kirk cites my paper as arguing that “we should reject the inference from conceivability to possibility”. It is true that others that have pressed versions of the ‘anti-zombie’ argument for this conclusion, I am not one of them. I want to grant the link between conceivability and possibility. It is true that I harbor empiricist leanings but if I were a rationalist I would find Chalmers’ CP thesis very attractive; but even so the zombie argument is inconclusive because we cannot simply assert that zombies are conceivable.
My complaint against the zombie argument has always been that the move from (1) ‘zombies seem conceivable to me’ to (2) ‘zombies are ideally conceivable’ is question begging. The only thing we really have evidence for is (1) but it is (2) that is actually used in the zombie argument. That this move is illegitimate is shown by the fact that shombies and zoombies seem conceivable to me (and others it turns out) but if I were to then say that they were ideally conceivable I would be accused of begging the question. Both zombies and shombies seem conceivable but only one of them can actually be ideally conceivable and importantly we have no a priori reasons that can decide which is which. Rather what seems to be happening is that one’s intuitions are tracking the theory that one accepts, perhaps implicitly. Thus we don’t know if zombies are ideally conceivable at this point. Nor do we know if shombies are. Both seem to be conceivable to various people but we don’t have enough empirical knowledge of the brain to decide. From this I draw the meta-lesson that we should deprioritize the a priori arguments for and against physicalism. What we need to do now is focus on specific theories of consciousness (like higher-order theories, say 🙂 ) and brain science. Even if we can in principle know a priori that the mind is just the brain, or that it isn’t, the way that we will come to know is empirical (just like water and H2O: even if it is in principle knowable a priori that water is H2O (because on can deduce one set of facts from the other) we discovered it empirically. A priori arguments played no positive role in the discovery).
Richard Brown 
What are “shombies”? Same thing as “anti-zombies”? If so, it certainly _seems_ easier to conceive of how an otherwise fully human being could lack consciousness than how consciousness could lack its physical counterparts.
But the problem is that the existence of consciousness itself is inconceivable. Why are almost all philosophers so ready to concede its existence? Because we know directly that we’re conscious? Doesn’t this inference depend on the “myth of the given.”
Hi Stephen,
yes, a shombie is a micro-physical duplicate of me which has no non-physical properties but is never the less conscious in the very same way that I (or you) actually am (/are). I think these are the same as Frankish’s anti-zombies (though I like ‘shombie’ better than ‘anti-zombie’). Is that what you take them to be? From what you write it sounds like you are talking about something else (ghosts)…
As for the second question, do you really have doubts that you have conscious experience? ‘The Given’ is a highly theoretical claim to the effect that we can have non-conceptual knowledge of the contents of perception (or something like that) but that is a different question from whether or not I know that I am not a zombie.
It’s a bit of a shame that your view was mischaracterized. I’m currently writing an essay where I support your strategy against a priori argumens of the classical anti-physicalist sort.
I’m not mischaracterizing your view by saying that instead of denying any premise in the conceivability argument you neutralize the argument by replacing the first premise (“zombies are conceivable”) with a disjunction of it and its denial, am I? (The argument being that shombies seem–at least–just as conceivable as zombies, and they are incompatible in conjuction, so how do you know which is ideally conceivable?)
Hi Michael, send me a copy of the paper when it’s finished…I’d be interested to read it.
I think that the parenthetical remark is on the money but I don’t know if I would say that I replace the first premise with a disjunction of it and its denial. Rather it seems to me that we have a conditional premise: if zombies are ideally conceivable the physical is false (and if shombies are conceivable then dualism is false). This does get you a disjunction: Either zombies are not ideally conceivable or physicalism is false but that isn’t what you meant, I don’t think.
At any rate, I don’t think we know if they are or aren’t. To me zombies seem inconceivable, though I remember when I thought I could conceive of them. So I suppose I want to neutralize the argument by replacing the first premise with (1) from the post. Dave resists this kind of move in his 1996 book by saying that he doesn’t know what kind of evidence we could give for (2) besides (1) but given that shombies seem conceivable to me, and importantly to others, the intuitions come to a stalemate.
I think I understand. I just think, given that “x seem so-and-so does not entail “x is so-and-so”, all the anti-physicalist is justified in asserting is that “zombies are (ideally) conceivable or not”. Saying that “if zombies are ideally conceivable, then physicalism is false” is just summing up the original argument.
I wouldn’t be too exited about the essay if I were you. It’s just an exam paper for an undergraduate course in the philosophy of consciousness. The main topic is Quinian and Rortian ways of ignoring the mind-body problem. I’d love to hear what you think of it, of course, if you got the time to check it out. It’s due 1. june, so it’s finished till then.
And I absolutely think that the further claim that zombies are inconceivable can be argued. But what’s so elegant about your approach is that that argument is not even needed.
a little off topic I suppose but If I was in a dualist frame of mind – I think I can easily imagine how consciousness could lack its physical counterparts.
It is just simply a breach of a bridging law that I have no evidence for or understanding of anyway (besides the basic dualist argument itself).
I have a big problem with this concept of “ideally conceivable”. Presumably the word “ideally” is in there to counter the problem that we clearly can conceive of impossible things. (I can conceive of Santa Claus delivering presents to all the children in the world in one night, though I know perfectly well that it couldn’t physically happen.)
You talk about “ideally” doing the work of ruling out one of a pair of logically incompatible alternatives. So we could imagine that “ideally conceivable” means “conceivable in a way that is logically compatible with all our other conceptions”. That seems like a pointless position to me, as I’m fairly sure that every human being in the world has some conceptions which are logically incompatible – I’ve never met a perfectly consistent person. So if that’s what “ideally conceivable” means, then nothing is ideally conceivable.
What I think you really want to get at is “conceivable and consistent with (what we know about) the world”. So the possibility that there’s still some coffee left in my cup is “ideally conceivable” (even though, when I check now, I find there isn’t), whereas Santa Claus is not “ideally conceivable” (given everything we know about physics).
But that just seems like multiplying entities. There’s conceiving of things, and I can conceive of possible and impossible things. There’s the world, which by definition contains no impossible things. Now you seem to be inserting an additional concept in between them: “ideal conceiving”, which is a kind of conceiving that only conceives of possible things. This kind of “ideal conceiving” has never happened, because no-one knows all the rules of physics, so no-one is able to successfully limit their conceiving to possible things. So it’s not psychologically plausible. Moreover, it doesn’t do any useful work in the argument. The only test of “ideal conceiving” is to look at whether a concept is possible in the world. So for the purposes of the argument we might just as well say “possible in the world” (operationally: consistent with all the rules we believe we know to apply in the world).
Having now gone and read the SEP zombies entry, I see it’s not just you who is using this idea of ideal conceiving, so perhaps I shouldn’t have directed this at you! I still think the idea is wrong, though.