Towards the end of the discussion we began to discuss what was involved in conceiving of the shombie world. Dave seemed to think that doing so involved conceiving of a possible world where physicalism was true. This amounts to the claim that <>[](P–>Q), i.e. that it is possible that it is necessary that the physical facts of our world entail that there are qualitative facts. In S5 if something is possibly necessary it is necessary (this is intuitive since if there is one possible world where a necessary truth is true then, if it is to be necessary, it must be true at all worlds including the actual one). This way of reading the shombie/illuminati argument has it more like contemporary versions of the ontological argument.

This is a bad way of thinking about the shombie argument since once we start to think about the possibilities of necessities we have to think about the entire space of possible worlds and our intuitions about how this space will turn out become very untrustworthy. I agree with Dave that we are better off just trying to conceive of one specific possible world. So to conceive of the shombie world all we need to do is to conceive of one possible world where physical facts entail qualitative facts (or alternatively where qualitative properties just are physical properties). That world is negatively conceivable (call this the illuminati claim) and plausibly positively conceivable (call that the shombie claim). Now is this a world where physicalism is true? Well that depends on your views about the necessity of identity statements. As is well know there is a very simple proof of the necessity of identities. The following is taken from Kripke’s Identity and Necessity,

1. (x)(y)(x=y)–>(Fx–>Fy)

2. (x)[](x=x)

3. (x)(y) (x=y)–>([](x=x)–> [](x=y))

4. (x)(y) (x=y)–> [](x=y)

The first premise says that if x and y are the same thing then if x has a property y has that property also. The second premise just says that it is necessary that every object is self identical. The third premise is a substitution instance of 1. What it says is that if x and y are the same thing then if x has the property of being necessarily self identical then so does y. From that we get four since we know that [](x=x) is true (though I suppose one could block the argument if they denied this…maybe someone like Dave will do this?)

At any rate 3 makes clear the point I am trying to make. The postulated identity in the antecedent is one thing and the hypothesis that if there is an identity then it is necessary is another. Thus we do not have to conceive of the shombie world as one where it is possible that some necessary truth is true. We simply need to conceive of a world where P=Q for some subset of the total physical facts and some qualitative fact. It is true that this by itself will not rule out dualism. The dualist might counter that the shombie world is conceivable but dualism still might be true of our world (though as a side note this is a much less attractive view for the dualist since if they admit that it is possible to have shombies then we probably should be focused on empirically finding out which is true) but this can be ruled out independently with the above argument.

Towards the end of the discussion Barbara Montero brought up the possibly of what she called “blocker worlds”. A blocker world is one where there are illuminati, or shombies, but in addition there are nonphysical properties or entities that ‘block’ the qualitative properties. Thus in this world there are physical duplicates of us, the physical facts entail that there are qualitative facts, but the nonphysical blockers block these facts. Barbara and dave seemed to think this was a problem for physicalism. Jim Pryor suggested that it wasn’t since even though in this world there were no qualitative properties if one just took the physical facts by themselves we would get qualitative facts. Kati seemed to think that this world wouldn’t be a world where there was a minimal physical duplicate of me since a minimal physical duplicate is one that has only the properties that I do and nothing else. Others were pressing here suggesting that blocker world folk are minimal physical duplicates because they have all of the very same physical properties as I do. I seemed to think that these creatures wouldn’t really even be physical duplicates of me since the blockers were interfering with the physical processes in such a way as to make a physical difference (how else could they block the qualitative properties? Barbara suggested that the blockers were like aspirin, but this works by effecting physical processes…I mean clearly there is a physical difference between someone who took aspirin for a headache and someone who did not.)

Anyway, I have to get ready to head out to Benji Kozuch’s cog sci talk at the Graduate Center….

On Tuesday I attended a discussion with Kati Balog of her paper Zombies, Illuminati, and Metaphysical Gridlock which was very interesting.

She begins by thinking about zombies and the things they say. If there really is a world that is microphysically identical to ours but that lacks consciousness and one of those creatures is a microphysical duplicate of David Chalmers then it is reasonable to think that Zombie-Dave will be giving zombie versions of the zombie argument. Zombie-Dave will say things like that he doesn’t see how structure and function could suffice for phenomenal experience even though all the while he doesn’t have any phenomenal experience (he is a zombie after all). Zombie-Dave will even say things like from the fact that he can conceive of all of the physical facts without the phenomenal facts obtaining it follows that physicalism is false.

The response to this argument hinges on the distinction between negative and positive conceivability. To negatively conceive of something is simply to be unable to rule it out a priori. Positive conceivability involves something more. For Kati positive conceivability is just negative conceivability (i.e. not being able to rule something out a priori) plus the application of standard everyday concepts. This is a modest notion of positive conceivability that leaves no room for an act of the imagination or a special act of conceiving. At any rate, the response to the Zombie-Dave objection then becomes the claim that while Zombie-Dave might be able to negatively conceive of P & ~Q* (where Q* is Zombie-Dave’s conception of what a phenomenal property is) he cannot positively conceive of it.

One of the interesting things that came up at this point was whether or not zombie phenomenal concepts have any mode of presentation. Kati seemed to think that they did not. Since Zombie-Dave denies that phenomenal properties are physical/functional properties it seems right to say that the zombie phenomenal concepts do not present phenomenal properties as physical/functional properties. Given that zombies actually lack phenomenal properties then there doesn’t seem to be anything else that could be a mode of presentation. So Kati thinks that a zombie’s phenomenal concept refers to a physical state of the zombie’s brain but it doesn’t present that property to the zombie in any way. While this seems right, it also seems right to say that there is some way in which the zombie thinks about, discriminates, or is rationally responsive to things it would call red, blue, green, etc. If all one means by mode of presentation is something like ‘a way of thinking about the referent’ then there doesn’t seem to be any problem in saying that the zombie’s phenomenal concepts present the brain states in a certain way.

Kati then introduces Illuminati as an answer to the positive conceivability argument. Illuminati are creatures that are completely and only physical and which have phenomenal properties. I call illuminati ‘shombies’ Keith Frankish has called them ‘anti-zombies’. Are such creatures conceivable? Well, clearly they are at least negatively conceivable. As Kati argued, illuminati are negatively conceivable for the same reason that zombies are. There is nothing in our grasp of phenomenal properties that tells us one way or the other whether they are physical or not. This is an important point. Someone who denies this is what I call a type-A dualist. Type-A dualism seems to me to be clearly an unattractive view since it amount to no more than defining phenomenal properties into nonphysicality. The response to this negative conceivability argument is again to invoke positive conceivability and the a priority of the zombie intuition. if it is a priori that zombies are positively conceivable then it cannot be the case that illuminati are negatively conceivable.

At this point there are two ways one can go. Kati’s preferred way is to try and bolster the negative conceivability of illuminati by offering a coherent physicalist metaphysics and ontology. If one can give a coherent philosophical account in completely physicalist terms then it would seem to bolster the case for the negative conceivability of illuminati. Another way to go would be to invoke positive conceivability of shombies. The shombie argument starts from the premise that shombies are positively conceivable (or what I really think is that it starts from the premise that they seem positively conceivable). Kati is skeptical of this move since she thinks that someone like Dave might be working with a notion of positive conceivability that is strong enough to make shombies inconceivable. My feeling is that any such notion will also make zombies inconceivable. But we would have to see the actual account of positive conceivability in play. According to the one I have been working with, shombies certainly seem positively conceivable. I can actually imagine discovering that we are shombies via the use of a philosophical theory of consciousness (like a higher-order theory) and relevant brain science discoveries.

Dave’s objection was that zombies are more intuitively conceivable than shombies. Perhaps after the acquisition of a bunch of theory one could have the shombie intuition but regular people have the zombie intuition quite strongly and pre-theoretically. I wonder whether if some experimental philosopher actually asked a bunch of undergraduates whether Dave would be right. My experience is that at least some of my students have the shombie intuition quite strongly and seemingly pre-theoretically. But I really don’t see why this matters. That one theory is taken for granted doesn’t show that it is true. I can’t imagine that someone who objected to the heliocentric view of the universe by complaining that one needed a bunch of advanced physics under your belt to see how it could be true would be taken seriously. It might be true that our natural inclinations run towards dualism; I admit that mine did when I was an undergraduate…but I also thought that the structure of the atom mirrored the structure of the solar system.

So I think that the shombie argument is the natural next move in the debate, but Kati does not. She then wonders what we are to say if at the end of the day we end up with two theories that are mutually incompatible but equally simple, elegant, predictive, and supported by the empirical evidence? If the physicalist and the dualist are each able to offer complete metaphysical and epistemological frameworks that are both compatible with the totality of the findings from science then what are we to say? Do we say that there is a fact of the matter about which theory is correct? Or do we say that there is no determinate fact of the matter about which is true? Or finally do we say that the issue is merely terminological? Kati seems to think that the answer is indeterminate. I think it is probably just terminological at that point, though as I have been arguing recently, I wonder if the dualist can even give a coherent account of what nonphysical properties are and so I doubt that we will end up with two equal theories at the end of inquiry. It seems to me that if the debate between the dualist and the physicalist comes out to be indeterminate then there are no determinate facts at all. That is, once we go Quinian we can’t stop the backslide all way to the inscrutability of reference. I for one just can’t bring myself to believe this. I mean if it were true then the fact that there are no determinate facts is itself indeterminate; but what could that mean?

…or so it seems to me at first glance as I run out of the house to class…