Attributing Mental States

Friday I attended James Dow‘s talk at the CUNY Cogsci Speaker Series. He was concerned with answering the question of how people are able to ascribe various mental states to themselves. In particular he was interested in critiquing the account offered by Bermudez and developing an alternative account inspired by P.F. Strawson.

The standard account has it that we first come to see that we have certain mental states like belief, pain, etc and that these result in various behaviors (e.g. utterances as well as other behavior). We then notice that other people engage in these kinds of behaviors and then reason by analogy that since they exhibit behaviors like the ones that I do when I have a, say, pain these people must also be in pain. Thus the standard account has that we start with ascribing mental states to ourselves (I am in pain) and then use that ability to ascribe mental states to others (Doug is in pain).

Bermudez criticizes the standard account using a posteriori evidence from developmental psychology. In particular Bermudez uses data from the phenomenon of joint attention. In joint attention you have two observers each attending to some object, say a piece of fruit, and each aware that the other one is attending the same object. Bermudez argues that in order to be able to do this (and infants do it as early as 9 months old) the child must be representing the mother as seeing the object and attending to it. This, in turn, must mean that the child represents the mother under a psychological sortal; that is as seeing x and attending to x. This together with other evidence that suggests that the child does not at this point attribute mental states to itself  shows that the standard account can’t be right. Bermudez then argues that the best explanation of what is going on here is that the ability to attribute mental states to others constitutes the ability to attribute mental states to oneself.

Dow wanted to criticize Bermudez for using an a posteriori argument to establish something like logical dependence. Whatever that turns out to mean Dow’s basic concern was to develop the Strawsonian alternative and to argue that none of Bermudez’s arguments decide between his account and the new alternative. In short the Strawsonian alternative postulates that the child simply has the ability to pick out other persons. ‘Person’ here is used in the Strawsonian sense as of something which has both mental and physical attributes. Dow claims that in representing the mother as a person the child is neither representing their mother under any kind of sortal. They simply attend to the eye and where it is focused. This Strawsonian view is what Dow called a ‘no-priority’ view in that it holds that there is a logical dependance (whatever that is) between self and other ascriptions (at the very least it seems to mean that in order to have the one ability one must also have the other ability (and vice versa?) but that neither one develops before the other.

We were promised a transcendental argument that was supposed to establish this but we ran out of time.

Over drinks I had an interesting discussion with Josh Dulberger who was proposing a novel take on the simulation theory/theory theory debate. Traditionally these are thought to be opposed but Josh suggested that they need not be. He thought that the simulation might be used to generate data for the theory one employs of other people and their mental states. This is an interesting idea. He then suggested that if one thought this then one might be able to argue that the function of consciousness lay in enriching the data that one gets. Intuitively the idea is that consciousness gives one better access to ones own mental states and so boosts the amount of data that one has for one’s theory thus making the theory richer. He thought this was nice since one could adopt David Rosenthal’s higher-order thought theory of consciousness and then argue that Rosenthal is wrong that there is no function of consciousness using his own theory against him, so to speak. But there is a problem here. In Rosenthal’s account there must have been a time when there were people who were able to infer what mental states they were in from observing their own behavior (which includes verbal utterances). But since these people are not able to have these higher-order thoughts in a way that seems unmediated by inference they do not have conscious mental states yet. As they get better and better and attributing these kinds of states to themselves they get to the point at which these attributions no longer seem to be mediated by inference at which point they come to have conscious mental states. At the point just before they have conscious mental states their access to their unconscious mental states is just as good as it will be when they do have conscious mental states. They will have what seems to them to be a different kind of access to their mental states but they really just have the same access as before (only now it seems to them to be immediate and non-inferential). If this is right then Rosenthal’s account ia not committed to Dulberger’s claim that consciousness produces more data. Our Rosenthalian ancestors have all of the same data that we do even though all of their mental states are unconscious.

On an interesting side note Daniel Shargel pointed out an interesting difficulty for Rosenthal in this story. The Rosenthalian ancestors do not have any conscious mental states. At some point they acquire the appropriate concepts which enables them to have higher-order thoughts attributing (theoretical) mental states to themselves. On Rosenthal’s account the fact that these higher-order thoughts are mediated by inference means that they do not result in the target states becoming conscious. It is only once the higher-order thoughts are seemingly unmediated by inference that we get consciousness. But Shargel argues that when these Rosenthalians have their very first higher-order thought, whether mediated by inference or not, it will not seem to them to be so mediated since nothing seems any way to them (all of their mental states are unconscious). Shargel suggested that Rosenthal response to this was that the inference needs to be the product of some internal mental state. Since the Rosenthalians always make inferences based on external perceptions the higher-order thoughts they have are not of the right kind. I wonder if there is some other response he can give, but this is already too long!

Unconscious Trait Inferences

Friday I attended social psychologist James Uleman‘s talk at the CUNY Cogsci Speaker Series. His topic was unconscious trait inferences. A trait inference is exemplified by the following. Subjects are presented with a sentence, for instance, “she solved the mystery half-way through” which reliably produces subjects to infer a trait. In this case the trait is something like clever or smart. Combining his interest in trait inference with a generally accepted paradigm in social psych that contrasts traits with actions as being more abstract Uleman designed an experiment to test whether or not people make unconscious trait inferences. His experimental setup is as follows. He presents subjects with a picture of someone engaged in an activity (say reading a book) and underneath has a sentence like the one previously mentioned, though in some of the trials he includes the trait explicitly (i.e. “she was so clever she solved the mystery halfway through”). He lets subjects look at the picture and the sentence for up to 8 seconds. Then they are presented with the picture and asked whether or not the trait was explicitly mentioned in the sentence which described that picture. So, to take our earlier example, if a subject is presented with a picture of a women reading a book described by the sentence “she solved the mystery halfway through” and then later presented only with the picture and asked if the trait term appeared explicitly or not. The interesting thing is that he is able to show that people falsely remember the trait being explicitly stated in sentences where it did not explicitly appear. This is taken as evidence that the inference to the trait is made unconsciously.

Even more interestingly, Uleman was able to show that if one simply varies the geographical distance one is able to show that people make less trait inferences about people who are near to them than they do about people who are distant from them. To show this he presented subjects with the same pictures of the same women reading the same book. The only difference is that before the picture was presented subjects either saw a picture of Washington Square Park (these are NYU students so this is the near condition) or a picture of something in Florence Italy (with ‘Florence’ explicitly stated in the picture. Subjects in the distant condition made a statistically significant higher number of false recognitions (i.e. they said that the trait term explicitly occurred in the description when it actually did not more times) than did those in the near condition. What this is taken to show is that people make more unconscious trait inferences about more distant people than they do about near people.

But why? The explanation offered went as follows. When a person is distant it is not a good strategy to focus on what they are doing at the moment as that can change. Rather what one wants to do is to focus on central, relatively stable attributes of the person. On the other hand when a person is near it is important to focus on what they are currently doing rather than on abstract stable traits. This is a curious finding (many people resisted it) but it makes sense to me. These inferences are ‘unconscious’ because subjects are not instructed to make them. They are not given a rating task (i.e. rate the following pictures on how clever they are) which requires them explicitly to make the inference.

Perhaps even more interestingly Uleman was able to show that the notion of distance in play is not simply geographical. You get the same results when the distance is social (i.e. class related) or even in terms of power. People who are asked to remember a time when they had power over someone else (defined as ability to give or deny something to someone) make more unconscious trait inferences than people who were asked to remember a time when someone else had power over them. The idea here is that when one feels powerful one feels “above it all” and when one is powerless one has the issues “hanging over them”.

In the second half of the talk Uleman presented data on the issue of whether or not people treat traits as causes or descriptions. That is, do people treat, say cleverness, as a cause of the women solving the mystery halfway through. I did not really follow this half of the talk, but I did pick up on one interesting tidbit. He seemed to be suggesting that people who are asked to make these kinds of trait inferences explicitly are more likely to stereotype and scapegoat an out group than those that make these kinds of inferences unconsciously…this is interesting, though I am not sure what to make of it…in fact I may be misremembering it….

Kripke on the Structure of Possible Worlds

Yesterday I attended Saul Kripke’s talk at the Graduate Center (there are quite a few interesting talk coming up…also looking good are the cogsci talks). The title of the talk was “The Structure of Possible Worlds: a Preface to a statement” and was subtitled, “Prolegomena to a talk on possible worlds, some considerations” so maybe I didn’t really attend a talk. Much of the talk, um preface to a prolegomena to a talk, consisted of Kripke going over the history of his thinking on modality, punctuated with his usual wit and humor. My two favorite moments were (a) the one where, after talking for an hour (the scheduled length of the talk), he stops and says “I may have to go over because I haven’t come to the main point yet” and (b) the one where, while discussing modal realism, he says “what does God have to do to make a really existing merely possible world actual; give it a kiss?” Ah, that Kripke should have his own reality show…I bet it’d be really popular!

As to the content of the talk, or whatever, he seemed to be indicating that (he may have) changed his mind about how he conceives of possible worlds. Here is how he put it in the handout,

I used to think that a sufficient account of my view of what a possible world is might be given by something like a Russellian structured proposition describing it. Now i think that one cannot give an account of what a possible world is in and of itself, but only as part of the structure of all possible worlds, or at least that modal logic cannot rule this out. (Even if there is not a unique structure of all possible worlds, structures where the problem I have just described arise cannot be ruled out philosophically.)

A structured Russellian proposition is an abstract entity that has as its constituents the actual objects in the proposition. So, to modify the classic example, the proposition that Jennifer Aniston loves Brad Pitt has Jennifer Aniston (the actual person), Brad Pitt (the actual person), and the relation of loving as constituents and these constituents are ordered by the loving relation such that Jennifer loves Brad (which is a different ordering from Brad loving Jennifer). This is just a more refined way of putting the basic point of Naming and Necessity. When we ask if Al Gore could have won the election we are asking a question about the actual Al Gore. We are not talking about some distinct object which merely resembles Al Gore (or which merely has many of the same descriptions true of it). There is therefore no issue of how we re-identify Al Gore in various possible worlds; it is the actual Al Gore.

So why does he now think that we can’t do this? (Of course, he hasn’t really come to this conclusion officially. What he said was that it might be true and he sort of leaned towards thinking that it is true). The basic reasoning he employed relies on his argument that there can be objects which are indistinguishable in every way which are none the less distinct. There is no criterion of identity that distinguishes these objects; as Kripke put it “the only difference between them is that there is a difference.” His favorite example is the square root of -1, known as i. i is equal to whatever number equals -1 when multiplied by itself. This number is not on the real number line and so is known as an imaginary number. The problem comes when we realize that i and -i are distinct numbers and that everything that is true of the one is also true of the other. i and -i are distinct yet have no clear criterion of identity.

The problem that Kripke sees is that something like this might be true for possible worlds. To see this he talks about what he calls ‘grounded’ objects. So, let’s imagine a world where there is an person, let’s call him George, who does not exist in the actual world. Let’s say that George is the son of two people who actually exist but do not actually have kids. In the actual world the sperm and egg that come together to form George never meet, but they do in some possible world. So George is grounded in the actual gametes that he could be the product of. But there is also the possibility of ungrounded objects. So consider Georgette. Georgette is a women who does not exist in the actual world but does at some possible world, yet unlike George, Georgette is not the related to any past, present, or future actual person. The sperm and egg which come together to form Georgette at no time exist in the actual world; they are the products of an alternate history which does not overlap with the actual world (in this respect). Georgette is ungrounded.

So if there can be ungrounded entities then we can see that the following situation is possible. Imagine that there are two possible worlds each which has an extra hydrogen atom which is not related to anything that actually exists. These two extra hydrogen atoms are thus ungrounded. We can furthermore imagine that these two hydrogen atoms are indistinguishable from each other. Now if this is the case then the two possible worlds we are imagining are indistinguishable yet distinct. There is nothing that we could say about the possible world in and of itself that could distinguish between these two worlds. The only way that we could distinguish them is by noting their relative positions to each other in the overall space of possible worlds. Thus Kripke concludes that we cannot talk about individual possible worlds except in relation to the entire structure of modality, or to be more modest, he concludes that there is no a priori consideration that would rule this kind of automorphism out.

An interesting argument, and there is a lot more to say about it but I will come back to that later.

I’m Back, Baby!

Wow, it’s already September! I have had a very busy summer. I have just recovered from a massive hard drive failure which has cost me all of my photos and three new papers that I have been working on. Damn you Dell!! I know, I know; I should have backed it up. I don’t know what happened. I moved the damn thing to my new house (closer to LaGuardia) and it was working fine (so it didn’t break in the move) then it just stopped working. They tell me that no data can be recovered from it unless I am prepared to pay in excess of $2,000!! So that stuff is as good as gone. I should have been working on that stuff here instead of in a word file!!!! I did print out a hard copy of some of it, but even so I have substantially revised it since then…Oh well, live and learn. I am now the proud owner of a macbook pro and loving it…though I have Pages instead of Word and I am wondering if I should get MS Office. At any rate,  I am planning on posting the rework so I should be posting more often.

On a personal note, I got married! I just returned from my honeymoon (a seven day cruise to Mexico) and am trying to get my life back together again. Between the moving, the computer dying, and the two weeks out of town for the wedding/honeymoon, and the semester starting, I feel like everything is ass over teakettle.

I also recently became the editor of the Higher-Order Theories of Consciousness category over at PhilPapers, which I am loving. This is a fantastic resource that makes research in philosophy the way it should be: fun and exciting. And finally some exciting things are in the works for this year’s Consciousness Online and the official call for papers should be going out in the next week or two.

Zoombie Round-Up

There has been a bit of discussion of zoombies in the blogosphere of late and I want to keep track of them all so that I can respond to them so I am posting links to them.

1.) Intentional Objects‘ David Gawthorne

Richard Brown’s Zoombies and Shombies

2.) Brain Scam‘s Tony Alterman:

Zombie, Scmombie –Richard Brown’s Efforts to Ressurect Materialism

(and his reply to my reply) Return of the Zombie

3.) And then there’s Richard Chappell’s responses.

In our latest exchange he has acknowledged that the primary and secondary intensions of statements in Q may diverge but seems to think that translating those statements into “semantically neutral” language will still let the argument go through. So, just was “the watery stuff isn’t H2O” comes out true at Twin Earth, “the painful stuff isn’t C-Fiber firing” comes out true at the zombie world. But this move won’t work. Here is what Chalmers has to say about this:

Given the discussion above, one might try generating an anti-materialist argument by simply substituting primary possibility for metaphysical possibility in the original argument.

(1) P&~Q is conceivable

(2) If P&~Q is conceivable, P&~Q is 1-possible

(3) If P&~Q is 1-possible, materialism is false.

_______________

(4) Materialism is false.

On this reading, (1) and (2) are both plausible theses, but (3) is not obviously plausible. The reason is that materialism requires not the 1-impossibility of P&~Q but the 2-impossibility of P&~Q. That is, materialism requires that it could not have been the case that P were true without Q being true. This is a subjunctive claim about ordinary metaphysical possibility, and so invokes 2-impossibility rather than 1-impossibility.

A materialist might reasonably question (3) by holding that even if there is a world W verifying P&~Q, W might be a world with quite different ingredients from our own. For example, it might be that W does not instantiate true microphysical properties (those instantiated in our world), such as mass and charge, but instead instantiates quite different properties: say, pseudo-mass and pseudo-charge, which stand to mass and charge roughly as XYZ stands to H2O. Likewise, it might be that W does not lack true phenomenal properties, but instead lacks quite different properties: say, pseudophenomenal properties. If so, then the possibility of W has no bearing on whether true microphysical properties necessitate true phenomenal properties. And it is the latter that is relevant for materialism.

Still, it may be that the gap between 1-possibility and 2-possibility could be closed. In particular, when a statement S has the same primary intension and secondary intension, then a world will verify S iff it satisfies S, so S will be 1-possible iff it is 2-possible. If P and Q both have primary intensions that coincide with their secondary intensions, then so will P&~Q, and we could run the following argument:

 

(1) P&~Q is conceivable

(2) If P&~Q is conceivable, P&~Q is 1-possible

(3) If P&~Q is 1-possible, P&~Q is 2-possible.

(4) If P&~Q is 2-possible, materialism is false.

_______________

(5) Materialism is false.

Here, the truth of (3) requires that both P and Q have primary and secondary intensions that coincide. (from The 2-D Argument Against Materialism)

The Contestability of (P & ~Q)

The discussion of Richard Chappell’s post Understanding (Zombie) Conceivability Arguments: Part II over at Philosophy, etc has prompted me to clarify the sense in which I take (P & ~Q) to be contestable and the reasons whyI take  the primary and secondary intensions of statement in Q not to be  identical; as it turns out the two claims are related.

We first start with the primary and secondary intensions of a statement. Let’s take our old standby ‘water is H2O’ and our two ways of considering possible worlds as either actual or counter factual. So, ‘water is H2O’ is true when we consider any possible world as counter factual. This is because  ‘water is H2O’ is an a posteriori necessity. There are no worlds, considered as counter-factual, where water isn’t H2O. But there are possible worlds, which if we consider as actual instead of counter factual, ‘water is H2O’ comes out false. So, take Twin Earth. On Twin Earth ‘water is XYZ’ is true and so when we consider Twin Earth as actual ‘water is H2O’ is false. That is to say that if Twin Earth were the actual world ‘water is not H2O’ would be true (because ‘water is XYZ’ is true there). What we have here is the makings of the distinction between primary and secondary intensions. The primary intension of a statement is given by asking whether it is true or false at possible worlds considered as actual while the secondary intension of a statement is given by asking whether it is true or false at possible worlds considered as counter factual. In effect then the primary intension of a statement is given by some kind of reference fixing description and then we determine whether the statement is true or not by taking a possible world and letting the description fix the reference at that world and the secondary intension of a statement is given by assigning the actual reference of the terms in question and holding that fixed as we vary our counter factual worlds.

Primary and secondary conceivability are then defined in terms of the kind of intension at work. So, take ‘water is not H20’. Chalmers accepts that there is a sense in which this is not conceivable. This is the sense in which we give ‘water’ the reference that it actually has. Then ‘water is not H20’ is equivalent to saying ‘H20 is not H20’ which is a contradiction. But this is to use secondary conceivability. ‘Water is not H2O’ is still primarily conceivable since if we consider Twin Earth as actual it will be true. This is because we assign ‘water’ just the reference fixing description and so to say that water is not H2O is just to say that ‘the stuff picked out in the same way we pick out H2O is not H2O’ which is true at Twin Earth. This captures Kripke’s way of putting it. When we think that we are conceiving of water not being H2O were are really conceiving of a person who is in the same epistemic situation as we are when we pick out H2O but isn’t picking that stuff out (i.e. Twin Earth).  Now, Chalmers continues, the zombie argument relies only on primary conceivability, not secondary conceivability; in fact Chalmers himself accused my zoombie argument of relying on secondary conceivability and not primary conceivability. I think my response at the time isn’t as good as it could be because it focused on P and not Q So let me try and restate the case.

A crucial premise of Chalmers’ argument is that when it comes to pains and other phenomenal properties their primary and secondary intensions are identical. What that means is that the statements in question pick out the same property no matter whether we consider the world as actual or counter factual. This is supposed to capture Kripke’s claim that it is impossible for there to be someone in the same epistemic situation as someone who was in pain and yet for that person not to be in pain (and that it is impossible for there to be a person who was in the same epistemic situation as someone who wasn’t in pain and yet to be in pain. There is no appearance/reality distinction when it comes to pains. So then the upshot here is to try to show that there is a difference between the way ‘water is not H2O’ works and the way ‘pain is not C-fiber firing’ works that preserves Kripke’s general idea but is made precise by the 2-D framework. Kripke’s basic idea was that when we think that some identity is contingent what is really going on is that there is some identity statement involving a description that is contingent but this can’t be the way we explain away the seeming contingency of ‘pain is C-fiber firing’ since there  is no alternate contingent identity involving a description in the case of pains.  This translates into the 2-D framework as the claim that Kripkean a posteriori necessities have a contingent primary intension (i.e. ‘water isn’t  H2O’ comes out true at some possible world considered as actual) but ‘pain isn’t C-fiber firing’, according to physicalist, has a necessary primary intension (there are no worlds considered as actual where this comes out true).

 But what are we to make of this claim? Is it really the case that the primary and secondary intensions of ‘the painful stuff is C-fiber firing’ are  identical? Or another way of asking the question; can the painful stuff fail to be c-fiber firing at some possible world considered as actual even though the painful stuff picks out C-fiber firing here? The answer is arguably yes! This is something that may be surprising but it is arguably shown to be true by empirical results. In particular cases of Dental Fear show that we can pick out mental states as painful which are not pains. Pain Asymboilia also, arguably, shows that we can pick out pain states without picking them out as painful. So the primary intension of ‘pain is not C-fiber firing’ is contingent. There is a possible world, say, where the painful stuff is ABC, where ABC is some distinct property from C-fiber firing, and if that world were actual it would be true that pain is not C-fiber firing. But does that world threaten physicalism? Obviously not. It is not physically identical to our world so is no threat. What needs to be shown is that there is a possible world where you have C-fiber firing and no painful stuff. Is there one? Well, obviously there might be one that is physically distinct from ours (that is, a world that was NOT a micro-physical duplicate of ours, say with different laws of physics there, might have C-fiber firing and no painful stuff and if that world were actual then it would be true that ‘c-fiber firing isn’t pain’) but again this world is not threat to physicalism. But of course (P & ~Q) is supposed to describe a world that IS micro physically identical to ours and which lacks qualitative properties. But this clearly isn’t conceivable on the present account. To see this, compare the water=H2O case. Given that the watery stuff is H2O in the actual world we know that in a world micro-physically identical to ours is a world in which H2O is picked out by ‘the watery stuff’. So too, then, if pain=C-fiber firing in the actual world then we know that any world micro-physically identical to ours is a world in which C-fiber firing is picked out by ‘the painful stuff’. So IF physicalism is true of our world then zombies are not conceivable. But this is not to rely on secondary conceivability. This is to rely of the non-identity of the primary and secondary intensions of ‘pain is not C-fiber firing’ in just the same way as we do in the water/H2O case. This is why my view is in the Kripkean-tradition, and so akin to type B physicalism but not wholly so.

Notice that the upshot of this is that when the dualist says that (P & ~Q) is semantically neutral they are either wrong or do not threaten physicalism. When they go to explicitly fill in the place holder ‘~Q’ with statements like ‘RB is consciously having a pain’ they assign a semantics to terms like ‘pain’ where the primary and secondary intensions are identical, whereas a physicalist like me will assign those terms a semantics just like other natural kind terms (where these intensions are not identical). If you really were to remain neutral on this semantic issue the conceivability of (P & ~Q) is no threat to physicalism (since you need the premise (PI=SI) to make the argument go through). So to get the zombie argument off the ground you must assume a certain semantics for the terms in Q, just as to get the zoombie argument off the ground you have to assume a certain semantics for NP (namely one that stipulates that there are no qualitative properties in NP. This nicely mirrors the zombie argument where the dualist has to stipulate that there are no physical properties in Q). It may be the case that this is more obvious in the zoombie case but it still helps to expose the same flaw in teh zombie argument.

Happy Birthday!!

It has now officially been two years since I started Philosophy Sucks! I have had 300 posts, 1,714 comments, and 75,000 hits. Thanks to everyone who has stopped by and especially those who have stayed to engage in discussion, most of which has been challenging, thought provoking, and fun!

Ut vos es Bellator Victus Mortuus Tempus Fugit

Yes, indeed, time does flee when you are fighting the living dead!

It has been a year since the original zombies wars broke out around here, which led to all of the zoombie and shombie action. I was recently looking over some of these old posts and the debate between Richard Chappell and myself as I get ready to do the re-write for the Journal of Consciousness Studies (where this paper and others from Consciousness Online are slated to appear).

The basic claim that Chappell makes is that the zoombie argument is not really a parody of the zombie argument. The basic reason for this is his claim that there is an important dis-analogy between the zombie argument and the zoombie argument. This dis-analogy arises because the completed micro-physical description of the world contains qualitative facts, if it does at all, only implicitly. This opens up the conceptual gap between the physical and the qualitative in a way that leaves the physicalist susceptible to the conceivability argument.

The dualist on the other had think that the qualitative facts are primitive and must be added to a completed micro-physics explicitly. Since the qualitative is not reducible to any base facts that are not themselves qualitative the dualist is not susceptible to conceivability arguments in the same way that the physicalist is. Another way to make the point, and a way that I think Richard prefers to make the point, is in terms of asking what follows from a completed micro-physics. The original zombie argument tries to show that the qualitative facts do not follow from the complete physical facts. The zoombie argument doesn’t work this way. We do no build up the non-physical facts and then ask whether or not the qualitative facts follow from them. This is because the dualist claims that the qualitative facts have to added explicitly. There is no issue of whether the follow from any other kind of fact since they are taken to be primitive.

Now, clearly, there is this dis-analogy between the two arguments. But does it follow, as Chappell alleged, that this dis-analogy makes it “daft” to mount a conceivability argument against the dualist? Or, another charge from Chappell, does this dis-analogy make the zoombie argument a bad parody of the original zombie argument (actually he said that it was irrational to think so, but let’s not dredge that stuff up) or show that I have misunderstood the original zombie argument (yet a further gem from Chappell)?

To start with the first question, the answer is obviously ‘no’.  A conceivability argument just starts from the claim that something is conceivable and reasons to that thing’s being possible. If something follows from that possibility then fine.If not fine. In this case it is conceivable that NP, being the complete set of non-physical facts about the actual world, obtain without any qualitative properties included in NP. If this is conceivable then it is possible and if it is possible dualism is false. Is this a bad parody of the zombie argument? Only if you think a parody must be identical in every respect to the original. The point is that zoombie argument is like the zombie argument in the right respects; in particular in asserting the conceivability of p and reasoning from there. The fact that what is at issue in the zoombie argument is not “what follows from what” but is rather “what must be included in the complete non-physical description of a world that is non-physically identical to the actual world?” is irrelevant. All that maters is that the possibility of zoombies shows that qualitative properties are not non-physical properties.  Finally, does this show that the proponent of the zoombie argument misunderstands the zombie argument? I don’t think so. The zombie proponent holds that zombies are conceivable because there is a gap between our physical/functional concepts and our qualitative concepts; or in other words that there is no reason as of now to think that qualitative properties are physical properties. The physicalist like me will claim that this gap will be abolished as we reach the ideal limit and so zombies are prima facie conceivable but not ideally conceivable. The zoombie proponent holds that zoombies are conceivable because there is no reason to think that qualitative properties are non-physical and so no reason to think that they must be included in a complete description of a non-physical duplicate of our world. Clearly both of these (zombies and zoombies) can’t be ideally conceivable so a priori arguments won’t help us decide between theories of consciousness.