I’m back safe and sound in Brooklyn…still a bit dazed and confused, shocked and awed, and just generally jet lagged and irritable…I also just found out that I will be presenting my paper ‘Emotive Realism: A Mostly Neglected Kind of Expressivisim’ at the Second Annual Felician Ethics conference (in Jersey, so no flying!!!). This is good because the paper is basically a synopsis of my dissertation, which will get me back into thinking about metaethics after all of this consciousness/phil logic/phil language nonsense…
Greeting from Tucson! I am on my way out to hear a talk by Bernie Bars and Wolf Singer, so I haven’t much time. I hope to get to the comments that are building up.
I have recently been mounting an offensive against the back-from-the-dead Zombie argument against materialism. My most recent attempt was to offer a parody of the zombie argument to the effect that dualism is false (since I can conceive of non-physical zombies). This is, in my opinion, enough to show that the zombie argument against materialism is hopeless and misguided. Richard Chappell disagrees.
The zombie argument begins by providing an undisputed specification of the “physical respects” of the world. It then asks whether phenomenal consciousness logically follows from the specification. Our answer is ‘no’. That’s why physicalism is false.
This is of course nothing more than more of the usual question begging. Does phenomenal conscious follow from a complete physical description of the world that we live in? That depends on whether materialism is true or not. If it is, then OF COURSE it logically follows that there is phenomenal consciousness; if it is not then OF COURSE it doesn’t logically follow. The point is that this cannot be known a priori. To imagine otherwise is as absurd as saying that one can know a priori whether the caloric fluid theory of heat is true or not.
Chappell goes on to say
A proper analogy, then, would require building up the “non-physical zombie” world from an undisputed non-physical specification, just as we earlier built up a physical zombie world from an undisputed physical specification. But of course RB cannot do this. So that’s why the zombie argument cannot be turned against dualism in this way.
I, of course, cannot do that because there is no ‘undisputed non-physical specification’ of ANYTHING. So the fact that I cannot build up such a description is irrelevant. What is relevant is that I can imagine a creature just like me in all non-physical respects; therefore dualism is false.
OK, so I am running late…gotta go!!!
Having thought about this a bit, I am at a loss to understand why RC thinks it is so important that we ‘build up’ rather than ‘subtract’ when we do this conceiving. What’s the relevant difference?
I am conceiving of a world that is just like this one in all non-physical respects except that it lacks consciousness. Therefore dualism is false.
Does anyone think that this is agood argument? I do, and I am sure that the world is conceivable, so sorry guys.
In a few hours I will be on my way to Tucson for the big consciousness shin-dig! But first I have office hours and a full day of teaching…ah well. I may be slow in responding to comments (though I will respond to Josh in person in the form of a twenty minute drum solo entitled ‘Pain Asymbolics are in Pain, it’s just not Painful’ 🙂
There has been a surprising amount of talk about zombies recently around the blogosphere. Here I thought the zombie issue was settled back in the ’90’s; but I suppose that’s what I get for forgetting that there aren’t any solved problems in philosophy, and it is in the nature of zombies to come back from the dead so I suppose I shouldn’t be all that surprised.
At any rate this zombie flare-up was brought about by Richard Chappell’s argument against physicalism. It starts by claiming that there is a possible world where there are creatures exactly like us in every physical way but who lack conscious experience. They scream when stabbed and ohh and ah over Matisse but ‘all is dark inside’; they are merely going through the motions since they do not have any conscious mental experiences. Since this world is conceivable it is metaphysically possible and since this world is metaphysically possible that means that physicalism about consciousness is false. This is, of course, not new with Chappell; this is the argument developed by David Chalmers. Chappell then presses JAckson and Chalmers’ argument that the popular Kripkean response fails to meet the zombie challenge. He argues that the zombie world is conceivable and whatever we decide about the way we want to use our words (i.e. whether we decide to apply our word ‘consciousness’ to the zombies), the metaphysical possibility of that world is enough to refute physicalism.
I have been arguing that Chappell’s argument fails to address the most plausible physicalist response to the zombie argument (and that his defense of modal rationalism itself adopts a version of the Kripkean strategy). This is to deny that the zombie world is actually conceivable. Sure, it seems to Chappell that he is imagining a world where there are physical duplicates of me (or you) and no consciousness but he is really imagining a world that LOOKS a lot like there are physical duplicates of me (or you) which lack consciousness. This is what I have been calling the Kripkean response because it is exactly the strategy that Kripke adopts in Naming and Necessity. It seemed to people that they were imagining a world where water wasn’t H2O (or where Aristotle wasn’t Aristotle) but they are really imagining a world where there is stuff that LOOKS like water does to us which isn’t H2O (or a world where there is a person who LOOKS like Aristotle (or satisfies most or all of the descriptions that Aristotle satisfies in the actual world) who isn’t Aristotle). Why should we think this is really what is going on? There are many reasons:
1. Do Conscious Mental States Cause Behavior?
If the answer to this question is yes then it is obvious that zombies are inconceivable. The zombie world is a world physically just like ours but which lacks conscious experience. Conscious experience act as causes of behavior, so a world that lack them would not be one where things went on as usual. It would be a world that was missing a bunch of causes and so, if just like ours, would have creatures that looked like us but would not act just like us. This is basically the argument that John Perry developed in his “Knowledge, Possibility, and Consciousness”.
2. Do We Have Epistemic Access to Our Conscious Mental Experience?
If the answer to this question is yes then the zombie world is inconceivable. This is the argument developed by Robert Kirk in his book “Zombies and Consciousness” (and the one being talked about over at Overcoming Bias). Here is a quick summary of the argument (from my review of the book for phil. psych.)
The anti-zombie argument can be stated rather easily. According to the ‘zombist’ there can be a creature that is a molecule-for-molecule-duplicate of me and yet lacks phenomenal consciousness. At the same time they want to hold that we have ‘epistemic access’ to our phenomenal consciousness. These two claims are not consistent with each other. To see why, imagine a zombie world that is identical to ours except in respect of phenomenal consciousness. Since that world is just like ours we can assume that it is causally closed under the physical. Now, continues Kirk, it should be possible to add to that world whatever it is that the zombist thinks will transform it into a world that does have phenomenal consciousness. But since whatever we added would have to be nonphysical, since their world is identical to ours (excepting consciousness), and so could not interact causally with the physical world (which is closed under the physical), it follows that we could not know anything about these ‘e-qualia’. Therefore, we could not have ‘epistemic access’ to them.
To make this vivid he offers what he calls the ‘sole-pictures’ argument. Again, consider our zombie world. Let’s add whatever it is that the zombist thinks will transform it into a world like ours. Now let’s imagine that by a “strange shift in the natural laws” of the zombie world the visual processes that in me cause e-qualia instead cause
sequences of constantly changing pictures to appear on the soles of [the zombie twin’s] feet. The changing colored patterns on his soles are isomorphic to those neural process in the same way as my e-qualia are isomorphic…to similar process in my brain. (p. 45)
Is there any reason to think that the zombies will have any access to these sole-pictures? Kirk’s answer is ‘NO!’ If not then zombies are not conceivable. The zombist commits what he calls the ‘jacket fallacy’: They treat qualia as something that can be stripped off a world without changing anything in the way that I can remove a jacket and remain the same. In the second half of the book Kirk tries to construct a theory of perceptual-phenomenal consciousness that does not commit the jacket fallacy.
This argument is convincing to me, and others. Has anyone responded to it?
3. Do qualitative properties (partially) Constitute our Phenomenal Beliefs?
If the answer to this question is yes then zombies are inconceivable. This is the option that Chappell and Chalmers opt for. They argue that qualitative properties are epiphenomenal in that they do not causally interact with the physical states of my brain but since the partly constitute the phenomenal beliefs I have (or in other words, my beliefs about what phenomenal states I am in). My zombie twin will believe that he sees red when I do but whereas I have a belief whose content is partly constituted by the epiphenomenal non-physical property ‘redness’ (or whatever), my zombie twin’s phenomenal beliefs lacks this property entirely and so we have very different beliefs even though we are physically identical. This seems conceivable and so it may seem that this response avoids the kind of physicalist response I am suggesting. But this is too quick.
The reason it is too quick is because of the discovery of pain asymbolia. Pain asymbolia is a rare condition where people report that they are in pain, and can even tell you what kind of pain it is (burning, pinching, stabbing, etc) yet they do not feel it as painful. The distinctive painfulness of the pain is absent. Presumably then these patients have an our world equivalent of the kind of beliefs that Chappell and Chalmers take the zombies to have. But far from acting in the same ways that we do when we have the same beliefs + qualitative painfulness these pain asymbolics laugh and smile at the pains. So the world that Chappell is imagining is not physically just like ours. If it were then the zombies would not behave in all the same ways that we do.
All of these discoveries come from a posteriori investigation. Even on Chappell’s modal rationalism these all turn out to be a posteriori discoveries because they depend on which world is actual. A purely rational being would not a priori whether the answers to 1-3 were ‘yes’ or ‘no’ until looking at the world. This is the Kripkean strategy. Chappell hasn’t argued against it and it doesn’t fall prey to the arguments he does develop.
Here is the virtual presentation for my upcomming Tucson presentation (you may have to press play if it doesn’t automatically start after opening). It is also available on the side bar with the other virtual presentations. It is a decendent of the presentation I gave at the ASSC, but instead of sketching my view of the propositional attitudes as consisting of a qualitative mental attitude held towards some intentional content, I consider several objections to the argument raised by Rocco Gennaro, Josh Weisberg, and David Rosenthal. Comments are as always very welcome.