The Higher-Order Response to the Zombie Argument

I have been having a very interesting discussion with Richard Chappell about his argument against physicalism and for modal rationalism which got me to thinking. If the higher-order theory is right, any version of it, then there is a very nice response to the zombie argument to be made. The zombie argument depends on there being a possible world that is exactly like the actual world except that the people and animals that inhabit this world do not have any conscious experience. As I have been arguing with Richard, one promising response to this argument is to claim that we are not really imagining a world that is exactly like ours except without consciousness we are really imagining a world which looks a lot like this one and which has no consciousness.

But what kind of world would this be? There would have to be people that looked liked us and behaved like us. They would say and do all the things we would do but the would not have consciousness. There would be nothing that it was like for them when they cried or were in “pain”. If one thinks about this from the higher-order view point this is a description of a world where there are no higher-order representations. That is, this is a world where there are only first-order states and no accompanying higher-order states. But how could that world be exactly the same as this one? In this one the presence of the first-order states leads to the arrival of higher-order representations. Something must be different about this zombie world.

Chappell on the A Priori

The a priori seems to be on the rise of late, especially with defenders like Richard Chappell championing the cause. According to Chappell an ideallly rational being would have access to all the metaphysical possibilites. Given that we can ideally (or coherently)  conceive something we can infer that the thing in question is metaphysically possible. This is, of course, the basis for the zombie argument against materialism. Since we can coherently concieve of a zombie world (a world where there are beings like us in every physical way except that they lack conscious experience) that shows that consciousness cannot be a physical property.

The standard (Kripkean) objection to this line of argument is to try to distinguish between metaphysical and epistemic possibility. Some things that are epistemically possible (i.e. seem coherently conceivable) turn out to be impossible (a classic example is to point out that before you learn that the square root of 1,987,690.000 is 1409.855 (rounded up to the nearest thousandth) it is concievable that it be other than 1409.855 but once we find out what it is it is impossible for it to be otherwise. According to the materialist one of these things is the zombie world. While it seems that we can coherently concieve of such a world, we are actually missing some contradiction, or physical difference between our world and the zombie world and so it is not actually (ideally/coherently) concievable. 

Chappell objects to this line of argument for (at least) two reasons. The first has to do with the theoretical extravagance of the materialist’s claim that the identity between (say) H2O and water is necessary. It posits an unexplained strong necessity, wheras the modal rationalist (the one who thinks that it is a metaphysical possibility that water could be other than H2O, not just an epistemic possibility) doesn’t have to posit something like this. All that she needs to posit is a single uniform space of possibilities that we describe in various ways. The materialist has to posit a space of epistemically possible worlds and a seperate space of metaphysically possible worlds. Parsimony and simplicity seem to favore that modal rationalist here.

The second is an attack on the claim that calling something a rigid designator settles the dispute. As Chappell says,

Perhaps our term ‘consciousness’ is, like ‘water’, a rigid designator. But who cares about the words? Twin Earth still contains watery stuff, even if we refuse to call it ‘water’, and the Zombie World still lacks phenomenal stuff (qualia), even if we stipulate that our term ‘consciousness’ refers to some neurophysical property (and so is guaranteed to exist in this physically identical world).

Yes it will, IF we have settled the issue in favor of Chapell’s view and we then think that we are genuinely concieving of a real metaphysical possibility. If there is a question as to whether these kinds of possibility are distinct then Chapell has done nothing more than beg the question.

This is evidenced when he says,

Kripke himself noticed something along these lines. While we can imagine a world where watery stuff isn’t truly water, it’s incoherent to imagine a world where “painy” stuff isn’t truly pain. To feel painful is to be painful.

Pointing out that Kripke begs the same queston as you are beging is not a way to absolve yourself of beging the question. There is a legitimate case to made that being in pain and feeling pain are in fact two seperate things. The evidence for this comes, not from a priori reflection on the nature of pain, but from evidence from cognitive science.

 But suppose that you are not moved by this evidence and you still maintain that a priori analysis reveals that the zombie world is metaphysically (not just epistemically) possible. Is this a coherent position? One objection that immediately pops up is that on this view it seems that we can concieve of various possible worlds that result in contradiction. So, I seem to be able to concieve that God necessarily exists and that God necessarily doesn’t exist (or that numbers do and don’t necessarily exist). Since the claim that conceiveability entails possibility entails that God (or numbers) both necessarily exists and doesn’t exist only one of those possibilities can be a real metaphysical possibility; the other must be an epistemic possibility.

Chappell is of course aware of this objection and tries to deal with it in the post linked to above. Here is what he says,

I agree with Chalmers that the most attractive response for the modal rationalist here is to hold on to their strong position, and instead deny the… conceivability intuitions found, for example,…above. It isn’t at all clear that a necessary being, or a shrunken modal space, is coherently conceivable in the appropriate sense. The modal rationalist will want to hold that their position is not just true, but a priori. They would then expect opposing views to be refutable a priori, and hence not feature in any a priori coherent scenario. Of course, it would beg the question to merely assert: “the thesis is true and hence has no successful counterexamples”. But that is not what’s going on here. Rather, I hope to show that the modal rationalist can explicate their commitments in a way which makes clear exactly why, on their view, the meta-modal cases in question are not taken to be genuinely conceivable. If successful, this should suffice to undermine the charge of internal inconsistency or self-refutation.

The problem with this line of argument is that it commits the very ‘fallacy’ that Chappell accuses the Kripkeans of making. The strategy that he is here proposing is that of trying to show that there is some possible state of affairs that seems conceivable but which, on reflection, is not in fact metaphysically possible (i.e. that there are possibilities that (seem)concievable but are not metaphysically possible). But if there are possibilities that (seem) concievable but not metaphysically possible then we need an independent argument that the zombie world is not one of these worlds. No such argument has been given. Rather what Chappell does is to assume that it is in fact coherently concievable; but this cannot be assumed if there are any possibilities which (seem) concievable and are not metaphysically possible. Chappell’s own view commits him to there being such possibilites, so by his own view the modal argument against materialism is suspect.

Has Idealism Been Refuted?

So, I have been having a very nice and informative discussion with Brandon about Berkeley’s so-called “Master Argument” which got me to thinking. Has immaterialism been refuted? It seems to me not. Here is a brief, and no doubt sketchy, survery of some of the better known ‘refutations’.

I. Kant

Kant famously argued as follows:

I am conscious of my own existence as determined in time. All determination of time presupposes something permanent in prception. This permanent cannot, however, be something in me, since it is only through this permenent that my existence in time can iteself be determined. Thus perception of this permanent is possible only through a thing outside me and not through a mere representation of a thing outside me…(B276)

Let us leave aside the problems with applying the concept ‘thing’ to noumena. It seems clear that this is question beging against the immaterialist, for they will gladly admit that there is something outside their mind; namely immaterial ideas. Kant’s argument only establishes, if it establishes anything, that our experience is not possible if we are solipsists

2. Moore

Moore, as I understand it, argued that the nature of judgement refutes idealism. Our hudgments are about things that are outside our minds and this fact shows that not everything is in the mind. But again, this is nothing more than question beging for the same reasons as given above. What argument has been given that the things outside the mind are not themselves mental?

3. Armstrong

Armstrong identifies materialism with the view that only the postulates of physics are ultimately real. He then argues against immaterialism using something that is closer to my heart; namely the causal clusure of the physical. We have no reason to believe that there are immaterial substances because it would be utterly mysterious how they would causally act in the world. But yet again this is just question beging against the immaterialist from the get go. The immaterialist can happil;y admit that the only things that are ultimately real are the postulates of physics but then maintain that electrons and quarks are simply ideas out of which more complex ideas are composed.

So it seems to me that idealism is far from being refuted. Rather it just seems that people are sick of arguing about it…Now, I don’t mean to say that it is true (or that it is false; I am agnostic).

Are there any other refutations of idealism that I don’t know about?

God Vs. The Delayed Choice Quantum Eraser

This is the name of an experiment first proposed in 1982, and is the one that I have had in mind when talking about God and quantum mechanics. I realized that most of the comments I have received seem to be taking me to be talking only about the standard double-slit experiment; this is of course my own fault since I haven’t done a very good job of indicating what I had in mind. So, let me describe these results and then reformulate the argument.

We have to build up to this, so let’s start with the quantum eraser experiment. Here is how Brian Greene describes the experiment in his recent book The Fabric of the Universe.

A simple version of the quantum eraser experiment makes use of the double-slit set up, modified in the following way. A tagging device is placed in front of each slit; it marks any passing photon so that when the photon is examined later, you can tell through which slit it passed…when this double-slit-tagging experiment is run, the photons do not build up an interference pattern.

As he goes on to point out, this is what we would expect. Since we measure the photon’s path, we get the photons acting like particles. But then it gets weirder. As Green continues, the quantum eraser asks,

What if just before the photon hits the detection screen, you eliminate the possibility of determining through which slit it passed by erasing the mark imprinted by the tagging device?

The answer, as it turns out, is that the interference pattern shows up again. Which, is , uh, weird. But again it gets weirder with the delayed-choice quantum eraser. Greene describes it thus,

It begins with [the set-up of the quantum eraser], modified by inserting two so-called down-converters, one on each pathway. Down-converters are devices that take one photon as input and produce two photons as output, each with half the energy (“down converted”) of the signal. One of the photons (called the signal photon) is directed along the path that the original would have followed toward the detector screen. The other photon produced by the down-converter (called the idler photon) is sent in a different direction altogether. On each run of the experiment we can determine which oath a signal photon takes to the screen by observing which down-converter spits out the idler photon partner. And once again, the ability to gleen which-path information about the signal photons– even though it is totally indirect, since we are not interacting with any signal photons at all– has the effect of preventing an interference pattern from forming.

OK, so far so good. This is just a fancier version of what we have already talked about, with the exception that we are now no longer causally interacting with the signal photon. Everything we know about the signal photon we learn by observing the idler photon. But even so, we get the photons acting like particles. But we aren’t done yet. Again Greene

 Now for the weirder part. What if we manipulate the experiment so as to make it impossible to determine from which down-converter a given idler photon emerged? What if, that is, we erase the which-path information embodied by the idler photon? Well, something amazing happens: even though we’ve done nothing directly to the signal photons, by erasing which-path information carried by their idler partners we can recover an interference pattern from the signal photons[!!!!!!]

OK, so what this seems to show is that it is not anything that we do to the photon that determines which way it will behave. Rather what determines this is whether or not we are able to know which path the photon takes to the detector. Nothing changes here except our ability to know which path the photon took.

We can hammer home this point with one further modification of the experiment. Suppose that we set it up so that we could only get which-path information from some of the photons (and further that which ones we get this information about is random). Again Greene.

Does this erasure of some of the which-path information– even though we have done nothing directly to the signal photons– mean that the interference effects are recovered? Indeed it does– but only for those signal photons whose idler photons [had their which-path information erased]…If we hook up equipment so that the screen displays a red dot for the position of each photon whose idler photons [had their which-path information erased] and a green dot for all others, someone who was color-blind would see no interference pattern, but everyone else would see that the red dots we arranded with bright and dark bands– an interference pattern.

So, it is the knowledge of which-path information that determines which way the photons behave. Since God always has which-path information, whether he obtains it in such a way as to effect the physical world or not, He will never see the interference pattern. Or in other words, the wave like nature of reality will be hidden from Him.

Sheez! That took longer than I thought!!  

God and Quantum Mechanics: Round Two

I was re-reading the comments on an earlier post where I proposed a dilemma for God’s knowledge of the nature of the reality. I argued that if God knows the outcome of the the random events hypothesized in (some interpretations of) quantum mechanics then his knoweldge of these outcomes will interfere with the physical process in such a way as to ‘hide’ the wave-like nature of matter. If this is the case then God’s knowledge is necessarily limited and we would have discovered something about nature that God can’t know (i.e. that matter has wave-like properties).

 In the comments the main response, given separately by Richard C. and Eric Weinberg, seemed to be that God’s knowledge would be achieved in such a way that it did NOT interfere with the physical process. It would not bring out the collapse of the wave-function and so His knowledge is not mysterious. I disagreed with this objection, but then I started thinking that even if I grant the objection there is still a problem here. So let’s grant it and assume that God knows the outcome of teh random physical process in such a way that it does not disturb the process and so does not collapse the wave-function.

 But if that is the case then we have the same, but opposite, problem that we had before. Instead of the wave-like nature of reality being ‘hidden’ from God, it now looks like it is the particle-like nature of reality that is ‘hidden’. For, if His knowledge does not collapse the wave-function then He won’t ever see the constituents of reality acting like particles!

Either way, it looks like we have discovered something about reality that God couldn’t have discovered on His own…

58th Philosophers’ Carnival

Welcome to 58th edition of the Philosophers’ Carnival!

I am happy to be hosting the carnival again and glad to see that it seems to be doing well. I always liked the way that Avery did the 46th (international) Carnival and so I modeled this edition on his ‘psuedo-conference’ format. What follows is, indeed, a ‘narrow cross-section of philosophy from accross the web’.

Special Session on the Employability of Philosophers

  1. Presenter: Tom Brooks, The Brooks Blog
    The truth is out there: employers want philosophers
  2. Respondent: Rich Cochrane, Big Ideas
    The Value of a Philosophical Education

Symposium on Philosophy of Science

  1. Sharon Crasnow, Knowledge and Experience
    Is Science Based on Faith?
  2. Matt Brown, Weitermachen!
    Common Sense, Science, and “Evidence for Use”

Symposium on Race and Liberty 

  1. Richard Chapell, Philosophy, et cetera
    Implicit Interference
  2. Joseph Orosco, Engage: Conversations in Philosophy
    It’s Only Racism When I Say It Is

Invited Session

 Symposium on Philosophy of Consciousness

  1. Tanasije Gjorgoski, A brood comb
    The Myth of ‘Phenomenal/Conscious Experience’
  2. Richard Brown, Philosophy Sucks!
    Priming and Change Blindness
  3. Gabriel Gottlieb, Self and World
    Pre-reflective Consciousness: A Fichtean Intervention

Symposium on Metaphysics and Epistemology

  1. Marco, El Blog de Marcos
    Truthmaking and Explanation
  2. Kenny Pearce, blog.kennypearce.net
    What Does Bayesian Epistemology Have To Do With Probabilities?

Symposium on Philosophy of Religion

  1. Dave Maier, DuckRabbit
    D’Souza vs. Dawkins
  2. Enigman, Enigmania
    Is the Free-will Defence Defensible?
  3. Chris Hallquist, The Uncredible Hallq
    What’s the deal with philosophy of religion?

I hope you enjoyed! Be sure to check out future editions of the Philosophers’ Carnival.

    Submit your blog article to the next edition of philosophers’ carnival using our carnival submission form. Past posts and future hosts can be found on our blog carnival index page

Flamming LIPS!

So I just got back from the Long Island Philosophical Society meeting, where I presented Language, Thought, Logic, and Existence (the virtual version is here if you missed it, which considering that there was 10 people there, you probably did) it was early but I had a good time…in the afternoon I commented on a paper by Glan Statile called ‘Mind, Matter, and Religious Experience’ which argued that materialism about the mind was empirically false as shown by the near death experience of Pam Reynolds.

I argued that there was no evidence that she had had any experience during the one hour time that she was actually brainsead and that the details of her experience suggest that she had experience before and after the time she was literally dead. During the discussion I was asked if she was brain dead for the whole seven hours and had had some experience would I be convinced that materialism was false. I said that I thought I would and he said that I had conceeded too much.

So suppose that Pam had no electrical activity in her brain at time T1 and that later when she is awake she is able to recount details from T1 that she would only be able to know if she had experienced the events she described at T1. Glen was arguing that this would be empirical evidence that materialism was false, and I had been agreeing with this premise. But the suggestion was, why wouldn’t this instead be evidence that there was some other (physical) property of the brain, which we weren’t monitoring and which was responsible for generating experience. So, maybe electricity is just an accidental feature of the brain, and something else is responsible for generating experience (maybe spin, or whatever). So, if materialism is an empirical hypothesis, how could it ever be falsified?

I also had a very interesting discussion with Jonathan Adler about my claim that most moral truths are analytic, but I plan a seperate post for that.

Over at Brains…

In case anyone here doesn’t know, I am also a contributor to Brains a group blog in the philosophy of Mind, Psychology and Cognitive Science…if anyone is interested here are some links to my posts there…

1. When Platitudes Collide

2. The Qualitative Character of Conscious Thoughts

3. Do Horses Sense Their Riders desires?

4. Brain States Vs. States of the Brain

5. Multiple Realization  Vs. Multiple Instantiation

6. Just Like Home