Dispatches from the Ivory Tower

In celebration of my ten years in the blogosphere I have been compiling some of my past posts into thematic meta-posts. The first of these listed my posts on the higher-order thought theory of consciousness. Continuing in this theme below are links to posts I have done over the past ten years reporting on talks/conferences/classes I have attended. I wrote these mostly so that I would not forget about these sessions but they may be interesting to others as well. Sadly, there are several things I have been to in the last year or so that I have not had the tim to sit down and write about…ah well maybe some day!

  1. 09/05/07 Kripke
    • Notes on Kripke’s discussion of existence as a predicate and fiction
  2. 09/05/2007 Devitt
  3. 09/05 Devitt II
  4. 09/19/07 -Devitt on Meaning
    • Notes on Devitt’s class on semantics
  5. Flamming LIPS!
  6. Back to the Grind & Meta-Metaethics
  7. Day Two of the Yale/UConn Conference
  8. Peter Singer on Climate Change and Ethics
    • Notes on Singer’s talk at LaGuardia
  9. Where Am I?
    • Reflections on my talk at the American Philosophical Association talk in 2008
  10. Fodor on Natural Selection
    • Reflections on the Society of Philosophy and Psychology meeting June 2008
  11. Kripke’s Argument Against 4-Dimensionalism
    • Based on a class given at the Graduate Center
  12. Reflections on Zoombies and Shombies Or: After the Showdown at the APA
    • Reflections on my session at the American Philosophical Association in 2009
  13. Kripke on the Structure of Possible Worlds
    • Notes on a talk given at the Graduate Center in September 2009
  14. Unconscious Trait Inferences
    • Notes on social psychologist James Uleman‘s talk at the CUNY Cogsci Speaker Series September 2009
  15. Attributing Mental States
    • Notes on James Dow‘s talk at the CUNY Cogsci Speaker Series September 2009
  16. Busy Bees Busily Buzzing ‘Bout
  17. Shombies & Illuminati
  18. A Couple More Thoughts on Shombies and Illuminati
    • Some reflections after Kati Balog’s presentation at the NYU philosophy of mind discussion group in November 2009
  19. Attention and Mental Paint
    • Notes on Ned Block’s session at the Mind and Language Seminar in January 2010
  20. HOT Damn it’s a HO Down-Showdown
    • Notes on David Rosenthal’s session at the NYU Mind and Language Seminar in March 2010
  21. The Identity Theory in 2-D
    • Some thoughts in response to theOnline Consciousness Conference in February 2010
  22. Part-Time Zombies
    • Reflections on Michael Pauen‘s Cogsci talk at CUNY in March of 2010
  23. The Singularity, Again
    • Reflections on David Chalmers’ at the NYU Mind and Language seminar in April of 2010
  24. The New New Dualism
  25. Dream a Little Dream
    • Reflections on Miguel Angel Sebastian’s cogsci talk in July of 2010
  26. Explaining Consciousness & Its Consequences
    • Reflections on my talk at the CUNY Cog Sci Speaker Series August 2010
  27. Levine on the Phenomenology of Thought
    • Reflections on Levine’s talk at the Graduate Center in September 2010
  28. Swamp Thing About Mary
    • Reflections on Pete Mandik’s Cogsci talk at CUNY in October 2010
  29. Burge on the Origins of Perception
    • Reflections on a workshop on the predicative structure of experience sponsored by the New York Consciousness Project in October of 2010
  30. Phenomenally HOT
    • Reflections on the first session of Ned Block and David Carmel’s seminar on Conceptual and Empirical Issues about Perception, Attention and Consciousness at NYU January 2011
  31. Some Thoughts About Color
  32. Stazicker on Attention and Mental Paint
  33. Sid Kouider on Partial Awareness
    • a few notes about Sid Kouider’s recent presentation at the CUNY CogSci Colloquium in October 2011
  34. The 2D Argument Against Non-Materialism
    • Reflections on my Tucson Talk in April 2012
  35. Peter Godfrey-Smith on Evolution And Memory
    • Notes from the CUNY Cog Sci Speaker Series in September 2012
  36. The Nature of Phenomenal Consciousness
    • Reflections on my talk at the Graduate Center in September 2012
  37. Giulio Tononi on Consciousness as Integrated Information
    • Notes from the inaugural lecture of the new NYU Center for Mind and Brain by Giulio Tononi
  38. Mental Qualities 02/07/13: Cognitive Phenomenology
  39. Mental Qualities 02/21/13: Phenomenal Concepts
    • Notes/Reflections from David Rosenthal’s class in 2013
  40. The Geometrical Structure of Space and Time
    • Reflections on a session of Tim Maudlin’s course I sat in on in February 2014
  41. Towards some Reflections on the Tucson Conferences
    • Reflections on my presentations at the Tucson conferences
  42. Existentialism is a Transhumanism
    • Reflections on the NEH Seminar in Transhumanism and Technohumanism at LaGuardia I co-directed in 2015-2016

Levin on Brown

My paper Deprioritizing the A Priori Arguments Against Physicalism, which was a product of the online consciousness conference, directly grew out of blog discussions I had around here shortly after I started this blog in May of 2007 (which, by the way, I just noticed, means that the 10 year anniversary of Philosophy Sucks! is coming up soon!!)…at that time I had been interested in modal arguments against physicalism but had no plans at all of writing a paper on zombies. At any rate this paper has become my second most cited paper (and is even cited by the Stanford Encyclopedia of Philosophy’s entry on Zombies (and the Wikipedia one too!)) but it is usually cited en passant, so to speak, so it is nice to see some actual discussion of the argument.

Janet Levin discusses it in her paper Do Conceivability Arguments Beg the Question Against Physicalism? which was published in the 2014 issue of Philosophical Topics that I edited as a result of the 4th online consciousness conference. At the time I was putting the issue together I contemplated writing something about it in a brief response but decided to wait. ‘Better late than never’ is quickly becoming my motto!

Levin starts with Perry’s response to the zombie argument in his 2001 book Knowledge, Possibility, and Consciousness and I think this is a good place to start. As a bit of an aside Perry’s book  has been hugely influential on me. I read it in my philosophy of mind course, with Kent Bach, in the fall of 2001 and at the time I remember feeling that the identity theory was not really given the due that it deserved and then I saw Perry defending it and it gave me hope. I even invited him out to SFSU to give a talk to the philosophy club as a result and he did. This may have been my first attempt at organizing an academic event! The paper I wrote for that class, “Sticking to the Subject: My Response to Chalmers’ Response to Perry” became my writing sample when I applied to PhD programs. I rewrote it with feedback from the class and afterwards when I approached him with this as a potential writing sample….I think I used to have this up on my website at some point when I was in Connecticut but it seems to be lost now (especially after my pre-cloud computer crash back in 2004 or 2005). I  only have a vague notion of what was in that paper and it would be interesting to see it again.

(On another tangent I also recall this book influenced a paper I wrote for my epistemology class I had in the spring of 2002 (also with Kent Bach) where I argued that adopting Perry’s view showed us how we can say that when I play Resident Evil and have thoughts like “there’s a green herb in the basement” they come out true (and how this shows a way to avoid skepticism)).

…But back to Levin’s critique. Here is what she says,

In his (2010), Richard Brown argues that the zombie argument (and its relatives) beg the question; they seem compelling only to those who already assume that qualitative properties are not physical.

One thing that I think has become clear over the years is that I was not clear enough in the original paper about my background assumptions and intentions. I had been used to arguing with people like David Chalmers and Richard Chappell and they were both very strong supporters of a priori reasoning and some version of two-dimensional semantics. So when I said that the zombie argument begged the question I meant that it begged the question against a physicalist who accepted the link between conceivability and possibility. I was trying to show that even if you grant all of the other assumptions that dualists make they still do not have an argument against physicalism. I didn’t really intend this to be a claim that the zombie argument begged the question against those who accepted type-B physicalism, or who otherwise denied the link between conceivability and possibility (as I am in some moods likely to do).

So how was this supposed to play out? As Levin says, I attempt to show this by

…presenting conceivability arguments analogous to the Zombie Argument that aim to support, rather than undermine, physicalism.  In particular, Brown argues for the conceivability of Zoombies; that is (p. 50), ‘creatures non-physically identical to me in every respect and which lack any non-physical phenomenal consciousness’, and also of Shombies; that is (p. 51), ‘creature[s] that [are] microphysically identical to me, ha[ve] conscious experience, and [are] completely physical’, and suggests that arguments with such conceivability premises will seem as compelling to physicalists as the zombie argument seems to dualists.

I can see why she says this but I would like to clear this up a bit.

First, I never intended my paper to offer any support for physicalism. I took the point to be that we did not have any good reason to think it was false, or that the a priori arguments against it did not show it to be false (currently, that is. Whatever their potential to do so in the future amounts to they do not presently constitute a reason to think that physicalism is false). Perhaps this is in fact to offer some kind of indirect support for physicalism but even so the conceivability arguments she is here discussing were aimed at showing that dualism is false. So take the pair {zombie, shombie}. If one accepts a two-dimensional semantics and one buys the general arguments against strong necessitates, then only one of this pair is truly ideally conceivable and the other is necessarily inconceivable. That much is common ground between those who accept two-dimensional semantics )and I do for the purposes of this argument…and sometimes for other purposes as well). But which one of this pair is ideally conceivable? No one has really been able to show that either one leads to a contradiction.

So, as I stressed above, given this set of background assumptions then I think the zombie argument is question begging. It begs the question by assuming that it is zombies that are truly ideally conceivable and not shombies. But if I am working inside 2D semantics then I find shombies to be conceivable and so that means zombies have to be the ones that are ideally inconceivable, even if I cannot yet say why. It is at this point, from within the 2D framework that the standoff manifests most strongly. As the Stanford encyclopedia entry on zombies suggests the best option for the dualist like Dave is to maintain that shombies are inconceivable (Dave has said this as well) but when pressed on why they are all that can be said is that many people have found it very hard to see how physicalism could be true of consciousness. But that is just to say that shombies are incredible for him, just as zombies are for me.

And this is just what Levin herself says, as we’ll see below. She goes one to say,

More precisely, Brown argues that Zoombies and Shombies—along with zombies—are all prima facie conceivable, and contends (like the theorists discussed above) that one’s antecedent theoretical commitments determine one’s convictions about which of these creatures will be ideally conceivable, conceivable ‘in the limit’.  And, though he is officially neutral about what the ultimate outcome will be, he suggests that if we were to learn, and sufficiently attend to, all the (not yet discovered) physical and functional facts about the world, we would be able to recognize that these facts do indeed entail that certain of our internal states are conscious experiences.

I would balk at this way of putting things. It is true that I am neutral about which one is ultimately truly conceivable but I do not think that it must be the case that we end up being able to make these deductions. I only think this is a possibility and that it is not ruled out by the conceivability arguments against physicalism. I do think that for different people different combinations of zombies and shombies will seem to be conceivable/inconceivable and that it is one’s background theoretical commitments that tacitly determine which is which.

I will also say that one thing that has been somewhat disappointing is that the suggestion that we may be able to make deductions a priori from physical states to phenomenal states only when we have the relevant concepts, whatever those turn out to be. So, Mary cannot do it in her room unless she has the relevant phenomenal concept (I can be neutral on what exactly these are and do not mean to endorse any account of them here). I have always thought that this was the best way to respond to the Mary case and I do not see it being discussed very much. I wish it were!

The main problem Levin has with what I say is something she points out as a flaw in Perry’s argument as well. She says,

Brown characterizes his view as a species of (what Chalmers calls) Type-C physicalism, the view that, although zombies may be conceivable now, they would be inconceivable ‘in the limit’.   But of course dualists would deny this, and it’s worth getting clear about what, on Brown’s view, could account for the eventual inconceivability of zombies.  First (p. 49) he likens the (prima facie) conceivability of zombies for us now to the prima facie conceivability of H2O in the absence of water for those living in the early 18th century, and suggests that, just as further empirical discoveries made H2O without water inconceivable, so further empirical discoveries will do the same for zombies. But this argument, like the ones discussed above, relies on a questionable analogy.  At least arguably—as noted before—what enables us (and not our 18th century counterparts) to deduce water facts from H2O facts is not merely that we have increased our empirical information, although this, to be sure, is crucial.  In addition, we, at least implicitly, appeal to certain principles that go beyond one’s empirical or methodological ‘theoretical commitments’; in particular, that the referent of ‘water’ is a  (natural) kind of stuff (e.g. the stuff that fills our lakes and comes out of our faucets or, alternatively—pointing to a lake or a puddle—that kind of stuff), and that natural kinds are to be individuated by their compositional properties (such as being composed of H2O).  But it is not clear that there are analogous principles which, when combined with our knowledge of the structure and function of the brain and central nervous system, would permit the deduction of facts about conscious experience from even a complete statement of the physical and functional facts.  And thus, it seems, it is plausible to think that even those committed to physicalism and open to further information about the structure and function of the brain will continue to find zombies conceivable.

I think I partially agree with what she is saying here. Especially with respect to the ‘extra empirical’ factors relevant to theory adoption in general.

Levin’s comments can be made especially poignant for the ‘water is H2O’ example. To anyone really interested in these issues I would recommend  reading Hasok Cheng’s book Is Water H2O? Evidence, Realism, and Pluralism, which was recommended to me after a talk I gave in Taiwan at the Academia Senica. This book really clarified a lot of the technical philosophical and empirical issues about the theoretical identity of water and H2O and I think it does highlight similar kinds of extra empirical forces at work in the history of science. I highly recommend it to anyone interested in these issues. But I am not sure why this kind of point is supposed to count against  the claim I am making. It seems to me to further support it!

If I am reading Levin right it looks like she is arguing that we may be Type B physicalists at the limit. That is, we may learn all of the physical facts and yet still find that zombies are conceivable even if we become otherwise convinced that physicalism is true. I agree that this is a possibility and this is why I think it is correct to say none of these arguments (employing zombies or shombies) are question begging tout court. They beg the question against a particular way of thinking about physicalism.

I also tend to agree that in the background of my thinking is something like what she points to about natural kinds. Especially in this case where I am interested in being as close to two-dimensional semantics as possible (because part of me thinks it is nice view to have). If one takes that point of view then consciousness is similar enough in that it can be picked out by a primary intension. We can, I think, attend to specific instances of phenomenal consciousness and say ‘that kind of stuff’ and thereby pick something out. So while I agree that my way of thinking is not the only way or forced up on in any way I am more concerned with arguing that this way of thinking is not (currently) threatened by any a priori arguments.

This is because my aim is not to establish physicalism but to show that arguments aimed at undermining it don’t do so without further assumptions. Even if you grant that the ideal conceivability of zombies would show that physicalism is false we need more than that. We need to also know that zombies are in fact ideally conceivable, and that is why homies are problematic. They must be inconceivable but then why can I, and so many others, conceive of them? The reason is, I suggested, that neither side has been able to show what contradiction is (or could be) entailed by the other side. Dualists and type B physicalists correctly point out that no one has made a successful case for why zombies are  inconceivable but, less often pointed out of late, it is also the case that no one has shown what contradiction is entailed by shombies. As far as we can tell at this point either both are ideally conceivable and so 2-dimensional semantics and modal rational fail or only one of the pair is ideally conceivable and we don’t presently know which one it is.

I think that Levin herself arrives at something like this position as well, as we’ll see. She goes on to say,

In a related argument, Brown suggests (p 55) that what could permit ‘the deduction of the phenomenal facts from the physical facts is the (for us) a posteriori discovery of identities between phenomenal and physical properties’.  But given the asymmetry discussed above, one may wonder, on behalf of dualists, what makes it plausible to think that any such a posteriori discovery could occur.  The answer, Brown maintains (pp. 55-56), is that further empirical investigation is likely to show that (contrary to Chalmers, et al and also Type B physicalists) ‘we will have discovered that phenomenal properties can be explained in broadly functional terms’, and goes on to argue that ‘this does not thereby endorse Type A physicalism.  It is just to point out that I cannot really conceive of anything else doing any explanatory work…No one has ever given anything like a proper account of what non-physical properties are or how they explain phenomenal consciousness.’

This, however—as for Perry—seems to be a matter not of zombies’ being inconceivable, but rather incredible, and the plausibility of Type C physicalism depends on the plausibility of the former, stronger, claim.  In short, there is no particular reason to think that any further discoveries of the neural structure of the brain and psychological laws governing mind-body interactions will provide information of a different sort from the information we have now.  And given that there seem to be no a priori links between physical (or physical-functional) and phenomenal concepts, and no a priori principles determining the nature or essential properties of the items denoted by our phenomenal concepts (other than that they must feel a certain way), it’s hard to see how zombies could become inconceivable—even in the limit.

Here I completely agree with her and in fact I think this is part of the point that I was trying to make.  Some people seem to find zombies conceivable, some people seem to find shombies conceivable. Since I am assuming that our reasoning capabilities are good enough for this (another common assumption between Chalmers and I for this argument) that leaves only empirical or conceptual issues left. So I agree that we haven’t yet got the story. I have argued that something like the higher-order theory will help but really the larger point is that we need a theory of consciousness and empirical data to move forward.

Again I would also point out that I think that part of the story here must invoke something about how these identities could be established. Here I think we could have a 2D version but also a version like that of Ned Block (that is a non-two-dimensional account). I am attracted to both kinds of pictures about the way these identities will be discovered.

But all of that to one side the whole point is that we cannot start from the assumption that zombies are in fact ideally conceivable. They may *seem* to be so *to you* given what *we know now* but this is not at all the same thing as their actually really being ideally conceivable, as shombies show. If one or the other were truly ideally conceivable *at this point in time* then we wold be able to show what contradiction is entailed by the zombie or shombie world. Thus, until that can be done, instead of ‘physicalism is false’ the best we get from the zombie argument is ‘it seems to me now that physicalism is false’. I hope it goes with out saying that I think the same is the case for the a priori arguments from the physicalist.

On a final note, Levin says in a footnote that Thomas Nagel in his 1965 paper Physicalism discusses cases like zoombies. Zoombies were supposed to be non-physical duplicates of me which lack consciousness. These creatures have all of my non-physical properties and yet they do not have consciousness. This seems conceivable to me, but is this what Nagel is talking about? When I went and re-read that paper it seemed like a warm up for his Bat paper and at the end he is talking about indexical information (which seems to be part of the story about how I became part of PQTI in Chalmers’ work and may be a precursor to Perry’s work). Maybe this is what she meant? I might have to re-re-read it…anyone else see the similarity?

Chalmers on Brown on Chalmers

I just found out that the double special issue of the Journal of Consciousness Studies devoted to David Chalmers’ paper The Singularity: A Philosophical Analysis recently came out as a book! I had a short paper in that collection that stemmed from some thoughts I had about zombies and simulated worlds (I posted about them here and here). Dave responded to all of the articles (here) and I just realized that I never wrote anything about that response!

I have always had a love/hate relationship with this paper. On the one hand I felt like there was an idea worth developing, one that started to take shape back in 2009. On the other hand there was a pretty tight deadline for the special issue and I did not feel like I had really got ahold of what the main idea was supposed to be, in my own thinking. I felt rushed and secretly wished I could wait a year or two to think about it. But this was before I had tenure and I thought it would be a bad move to miss this opportunity. The end result is that I think the paper is flawed but I still feel like there is an interesting idea lurking about that needs to be more fully developed. Besides, I thought, the response from Dave would give me an opportunity to think more deeply about these issues and would be something I could respond to…that was five years ago! Well, I guess better late than never so here goes.

My paper was divided into two parts. As Dave says,

First, [Brown] cites my 1990 discussion piece “How Cartesian dualism might have been true”, in which I argued that creatures who live in simulated environments with separated simulated cognitive processes would endorse Cartesian dualism. The cognitive processes that drive their behavior would be entirely distinct from the processes that govern their environment, and an investigation of the latter would reveal no sign of the former: they will not find brains inside their heads driving their behavior, for example. Brown notes that the same could apply even if the creatures are zombies, so this sort of dualism does not essentially involve consciousness. I think this is right: we might call it process dualism, because it is a dualism of two distinct sorts of processes. If the cognitive processes essentially involve consciousness, then we have something akin to traditional Cartesian dualism; if not, then we have a different sort of interactive dualism.

Looking back on this now I think that I can say that part of the idea I had was that what Dave here calls ‘process dualism’ is really what lies behind the conceivability of zombies. Instead of testing whether (one thinks that) dualism or physicalism is true about consciousness the two-dimensional argument against materialism is really testing whether one thinks that consciousness is  grounded in biological or functional/computational properties. This debate is distinct and orthogonal to the debate about physicalism/dualism.

In the next part of the response Dave addresses my attempted extension of this point to try to reconcile the conceivability of zombies with what I called ‘biologism’. Biologism was supposed to be a word to distinguish the debate between the physicalist and the dualist from the debate between the biologically-oriented views of the mind as against the computationally oriented views. At the time I thought this term was coined by me and it was supposed to be an umbrella term that would have biological materialism as a particular variant. I should note before going on that it was only after the paper was published that I became aware that this term has a history and is associated with certain views about ‘the use of biological explanations in the analysis of social situations‘. This is not what I intended and had I known that beforehand I would have tried to coin a different term.

The point was to try to emphasize that this debate was supposed to be distinct from the debate about physicalism and that one could endorse this kind of view even if one rejected biological materialism. The family of views I was interested in defending can be summed up as holding that consciousness is ultimately grounded in or caused by some biological property of the brain and that a simulation of the brain would lack that property. This is compatible with materialism (=identity theory) but also dualism. One could be a dualist and yet hold that only biological agents could have the required relation to the non-physical mind. Indeed I would say that in my experience this is the view of the vast majority of those who accept dualism (by which I mostly mean my students). Having said that it is true that in my own thinking I lean towards physicalism (though as a side-side note I do not think that physicalism is true, only that we have no good reason to reject it) and it is certainly true that in the paper I say that this can be used to make the relevant claim about biological materialism.

At any rate, here is what Dave says about my argument.

Brown goes on to argue that simulated worlds show how one can reconcile biological materialism with the conceivability and possibility of zombies. If biological materialism is true, a perfect simulation of a biological conscious being will not be conscious. But if it is a perfect simulation in a world that perfectly simulates our physics, it will be a physical duplicate of the original. So it will be a physical duplicate without consciousness: a zombie.

I think Brown’s argument goes wrong at the second step. A perfect simulation of a physical system is not a physical duplicate of that system. A perfect simulation of a brain on a computer is not made of neurons, for example; it is made of silicon. So the zombie in question is a merely functional duplicate of a conscious being, not a physical duplicate. And of course biological materialism is quite consistent with functional duplicates.

It is true that from the point of view of beings in the simulation, the simulated being will seem to have the same physical structure that the original being seems to us to have in our world. But this does not entail that it is a physical duplicate, any more than the watery stuff on Twin Earth that looks like water really is water. (See note 7 in “The Matrix as metaphysics” for more here.) To put matters technically (nonphilosophers can skip!), if P is a physical specification of the original being in our world, the simulated being may satisfy the primary intension of P (relative to an inhabitant of the simulated world), but it will not satisfy the secondary intension of P. For zombies to be possible in the sense relevant to materialism, a being satisfying the secondary intension of P is required. At best, we can say that zombies are (primarily) conceivable and (primarily) possible— but this possibility mere reflects the (secondary) possibility of a microfunctional duplicate of a conscious being without consciousness, and not a full physical duplicate. In effect, on a biological view the intrinsic basis of the microphysical functions will make a difference to consciousness. To that extent the view might be seen as a variant of what is sometimes known as Russellian monism, on which the intrinsic nature of physical processes is what is key to consciousness (though unlike other versions of Russellian monism, this version need not be committed to an a priori entailment from the underlying processes to consciousness).

I have to say that I am sympathetic with Dave in the way he diagnoses the flaw in the argument in the paper. It is a mistake to think of the simulated world, with its simulated creatures, as being a physical duplicate of our world in the right way; especially if this simulation is taking place in the original non-simulated world. If the biological view is correct then it is just a functional duplicate, true a microfunctional duplicate, but not a physical duplicate.

While I think this is right I also think the issues are complicated. For example take the typical Russellian pan(proto)psychism that is currently being explored by Chalmers and others. This view is touted as being compatible with the conceivability of zombies because we can conceive of a duplicate of our physics as long as we mean the structural, non-intrinsic properties. Since physics, on this view, describes only these structural features we can count the zombie world as having our physics in the narrow sense. The issues here are complex but this looks superficially just like the situation described in my paper. The simulated world captures all of the structural features of physics but leaves out whatever biological properties are necessary and in this sense the reasoning of the paper holds up.

This is why I think the comparison with Russellian monism invoked by Dave is helpful. In fact when I pitched my commentary to Dave I included this comparison with Russellian monism but it did not get developed in the paper. At any rate, I think what it helps us to see is the many ways in which we can *almost* conceive of zombies. This is a point that I have made going back to some of my earliest writings about zombies.  If the identity theory is true, or if some kind of biological view about consciousness is true, then there is some (as yet to be discovered) property/properties of biological neural states which necessitate/cause /just are the existence of phenomenal consciousness. Since we don’t know what this property is (yet) and since we don’t yet understand how it could necessitate/cause/etc phenomenal consciousness, we may fail to include it in our conceptualization of a ‘zombie world’. Or we may include it and fail to recognize that this entails a contradiction. I am sympathetic to both of these claims.

On the one hand, we can certainly conceive of a world very nearly physically just like ours. This world may have all/most of the same physical properties, excepting certain necessary biological properties, and as a result the creatures will behave in indistinguishable ways from us (given certain other assumptions). On the other hand we may conceive of the zombie twin as a biologically exact duplicate in which case we do not see that this is not actually a conceivable situation. If we knew the full biological story we would be, or at least could be, in a position to see that we had misdescribed the situation in just the same way as someone who did not know enough chemistry might think they could conceive of h2o failing to be water (in a world otherwise physically just like ours). This is what I take to be the essence of the Krpkean strategy. We allow that the thing in question is a metaphysical possibility but then argue that it is actually misdescribed in the original argument. While misdescribing it we think (mistakenly) we have conceived of a certain situation being true but really we have conceived of a slightly different situation being true and this one is compatible with physicalism.

Thus while I think the issues are complex and that I did not get them right in the paper I still think the paper is morally correct. To the extent that biological materialism resembles Russellian monism is the extent to which the zombie argument is irrelevant.

Professor Shombie

I had planned on posting here more once back from Taiwan but that has’t exactly worked out! If one wants to see the videos from the conference in Taiwan they are here and I will eventually write up a paper from my talk (and the one I gave at the Grad Center). Even so lots has been going on. I am also happy to announce that I am now officially Tenured and promoted to Full Professor! Tenured Full Professor…It hasn’t quite sunk in yet but it is still pretty cool.

In other news I am getting ready to head up to UConn to give a talk. I left UConn way back in 2003 to come to NYC and I went back in 2007 to participate in the Yale/UCONN graduate conference but I haven’t been back since then so I am looking forward to it! I figure since it is so close to Halloween I will talk about ways to kill zombies. In particular I have been thinking a lot about the 2D argument against dualism and plan to present an updated version of that. I have a draft up at PhilPaper which I wrote after my presentation at the Towards a Science of Consciousness conference back in 2012 and the helpful comments from Dave on the linked to post but I think I have a better way to present it now.

The main points are the same: The shombie argument is aimed at establishing the falsity of dualism, not the truth of physicalism. Physicalism can be formulated as the familiar [](P ⊃ Q) and dualism can be formulated as the claim that it is necessary that if all there is in a world is the physics of our world then there is no consciousness at that world. We can symbolize that as [](PT ⊃ ~Q). Here PT is the conjunction of the familiar P (a complete description of the fundamental microphysics of our world, laws and particles, etc) together with a ‘that’s all’ clause. To show that this is false we need to show that it is possible that we could have PT and at the same time Q. In symbols ◊(PT & Q). So the shombie argument is as follows. PT & Q is conceivable and so possible. From that it follows that [](PT ⊃ ~Q) is false. From here the main action is how to understand the that’s all clause. Dave suggested a modal and non-modal (see the paper or his comments) way to interpret it and I think either of those would work. There are tricky issues about parity here and whatever turns out to be the case for shombies should be the case for the zombie argument as well. So if we need to invoke modal notions, or notions of fundamentality to describe the shombie world then I am happy with that as long as we also need to do it to describe zombie worlds.

However that turns out I think we can describe the shombie world without any modal terms in any of the premises. I understand the shombie world to roughly be the following kind of world. For everything that exists in that world there is a physical property which is that thing. We can symbolize this as: (x)[∃y(y=x) ⊃ ∃z(Pz & (z=x))]. This says that for anything that exists there is some physical property which is that thing. Here one might object that the identity statement in the consequent already has modal notions smuggled in but I think we can get rid of this as well. The basic idea is that we have a non-modal way of understanding what it means to say that x is identical to y, it just means that if x has some property F then so does y. In symbols this is (x=y) ⊃ (Fx ⊃ Fy). We can substitute this into the above to get (x)[∃y(y=x) ⊃ ∃z(Pz & (Fz ⊃ Fx))] which is now a non-modal ‘that’s all’ clause. It says that for any object which exists there is some physical property (which may be very complex) such that if that property is a certain way then so is the physical object. It may be the case that I need something like ‘for all F, if z is F then x is F’ or maybe even ‘for all F, z is F if and only if Fx’ but either way there are no modal claims here. We simply imagine one world where consciousness is physical and that is enough to show that dualism is false. We do not need to imagine anything complicated like that it is possible that it is necessary that P entails Q.

In the course of re-working all of this it struck me that I spend a lot of time trying to show that the zombie argument (and related scenarios like inversions etc) are not relevant to the question of physicalism. Thus I think that in the shombie case if one is partial to modal rationalism (as I sometimes am) then only one of the pair (zombies, shombies) can be ideally conceivable and different people find them differently conceivable. Thus for us these intuitions are not helpful one way or the other. This was also the point I was trying to make in my short paper Zombies and Simulation which was in the JCS issue on Dave’s singularity paper. But another route to this kind of conclusion just struck me.

Suppose that the identity theory is true, so that consciousness in our world is (necessarily) physical, let us symbolize that as b=q, where b is some brain state and q is some episode of consciousness. If the identity theory is true are zombies conceivable (and you accept modal rationalism)? The answer seems to be ‘no’. For, suppose that b=q as we have said. Then someone who said that you could have a physical duplicate of me, which includes b, and yet lack consciousness, q, would be asserting both that b was and was not instantiated at the possible world in question. It is instantiated because I am described as being in brain state b and yet it is described as not being there because we are told that there is no q, even though we are assuming that b=q. This is like being told that there is H2O (and our laws of physics) and yet no water. If water is H2O then this is not conceivable.

So far so good, but what is often unnoticed is that we can conceive of a creature that is physically just like me except that it is not in brain state b (and so not having conscious experience q). It seems like there is nothing contradictory about the scenario where this creature behaves just like I do when I have the relevant brain state (and thus the relevant conscious experience). This will be a world where there are causal gaps, where, that is, the behavior of our world is duplicated but without the usual causes. So this creature may put its hand in the fire and in me this would cause brain state b (and thus conscious experience q) and this in turn would case me to yell etc. But the creature we are imagining puts its hand in the fire and does not go into the relevant brain state, but does go into the relevant states that cause behavior (and has the relevant beliefs, etc). This creature still has a brain and is very similar to me excepting for the fact that it has no conscious experience (due to lacking those specific brain states) and all of these strange causal gaps (to make its behavior indistinguishable from mine). This creature counts as a zombie, though not the kind that is relevant to physicalism. Thus one kind of zombie threatens the identity theory while the other does not. So which one is really conceivable? I find that I can only really make sense of the non-threatening kind (surprise! surprise!)But what kind of evidence could push us one way or the other? Once again I find conceivability (for now) to be of now use in answering questions about consciousness.

Ok enough for now! I am hoping to make it out to what should be a very interesting discussion of a paper by Jonathan Simon on how to conceive of pain inversions (I hope someday to write up some of the stuff that comes out of the nyu consciousness discussion group but we’ll have to see if Ryland lets me! 🙂

Towards some Reflections on the Tucson Conferences

As anyone who is even remotely interested in consciousness probably already knows, we are coming up on the big 20th Anniversary Towards a Science of Consciousness Conference in Tucson Arizona. Sadly I am not able to make it this year (due mostly to financial reasons) but I thought I would take a moment to reflect on my involvement with this conference.

I transferred to San Francisco State University in the Spring of 1997. I chose SF State over another college that had an interdisciplinary Cognitive Science program (I think it was Stanislaus, but I really can’t remember) mostly because I loved the city and was thrilled at the chance to set up shop in the Bay Area. I got there and had some adventures, taking Philosophy of Language with Kent Bach, which I really liked (some of the ideas I had in that semester eventually made it into my dissertation). But what really got me was the Philosophy of Mind course I took in the Spring of 1998 (also with Kent Bach), the same semester I was taking a Cognitive Science course. It was in those courses that I met someone who first mentioned the Tucson conference. I remember going home and using the dial-up modem (!!!!) to go online and look into this conference. It seemed really exciting (I also became aware of the Mind and Language seminar at NYU, which I really wanted to be a part of!).

I earned my Bachelors degree in 2000 and applied to exactly two graduate schools, which were NYU and Rutgers. I figured that if I was going to leave California it would be to go study consciousness and mind where it seemed to be flourishing. When I was rejected from both (no surprises there though I did get an offer from the Tisch School of NYU) I entered the graduate program at SFSU that same year. I started working with Mark Geisler in the psychology department and presented at my first professional conference with his lab (the Society for Psychophysical Research in Montreal, on a side note that conference was in October 2001, right during the Anthrax scare…not a good time to be flying around!!). Tucson2002
I suggested that we submit to the Tucson conference in Spring of 2002 and we did. Our lab had two posters at that conference. Mine was “EEG Response to Chromatic and Achromatic Hermann Grid Illusions” where I tried to show that the Herman Grid illusion was at least partially due to activity in V1. It was a great conference, and I remember being in one of the sessions, listening to a talk on how the brain processes information that allows a baseball player to catch a ball and the ways in which these players get it wrong when they talk about it. I thought to myself that it would be really cool to give a talk at this conference some day.

I came back to Tucson in 2006 to realize that goal and give my talk ‘What is a Brain State?’. My session was chaired by Hakwan Lau and I was exceedingly nervous. Even though I had presented at conferences before this was my first presentation in front of a significant number of people and I remember looking out at the audience and feeling a bit nauseated. Even so it was a lot of fun and I had some really good discussions with people afterwards.

I purchased the audio recording of my presentation and then dubbed it over a really bad video of the powerpoint slides so that you can relive this classic moment in Tucson history! Can you count all of the ‘ums’? I lose track…

I came back in 2008 to present “HOT Implies PAM: Why Higher-Order Theories of Consciousness are Committed to a Phenomenal Aspect for all Mental States, even Beliefs” which was less fun for me. My talk was at the end of the session and by the time it was my turn there was only 10 minutes left in the session (barely even enough time to get through the title!). For me it was a lot of flying (which I hate/am deathly afraid of) and a lot of money (which I don’t have and am not reimbursed for) and I thought it was not worth it at all. I remember drunkenly yelling at Uriah Kriegel that I thought that there was not very much time for discussion during the conference and that the conference should be about ideas and discussion rather than profit. Of course I found out how naive that was. The conference is not ‘for profit’ in any serious sense of that word and the format employed is fairly standard for science-based conferences. But it was partially because of my dissatisfaction with my experience that year that I started the Online Consciousness Conference in the summer of 2008.

The next time I was in Tucson was in 2012 when I presented “The 2D Argument Against Non-Materialism“. This was a very different experience. By this time I knew most of the people at the conference, including David Chalmers, and even worse most of them knew me! Perhaps Ironically I missed the days when I could slink into the back of a talk unnoticed by anyone and disappear right afterwards without a trace. I mean, there are worse things than hanging with cool and interesting people and talking about consciousness but it did bring home how much things have changed for me in the last 15 years!

photo by Tony Cheng

photo by Tony Cheng

Here’s to 20 more years!

Zombies vs Shombies

Richard Marshall, a writer for 3am Magazine, has been interviewing philosophers. After interviewing a long list of distinguished philosophers, including Peter Carruthers, Josh Knobe, Brian Leiter, Alex Rosenberg, Eric Schwitzgebel, Jason Stanley, Alfred Mele, Graham Priest, Kit Fine, Patricia Churchland, Eric Olson, Michael Lynch, Pete Mandik, Eddy Nahmais, J.C. Beal, Sarah Sawyer, Gila Sher, Cecile Fabre, Christine Korsgaard, among others, they seem to be scraping the bottom of the barrel, since they just published my interview. I had a great time engaging in some Existential Psychoanalysis of myself!

The 2D Argument Against Non-Materialism

On wednesday I gave my talk out here in Tucson. You can see a rehearsal of it below. The discussion was very interesting and I thought I would quickly jot down a few notes on what happened.

Right at about 1:00 minute into the talk Dave Chalmers spontaneously objected to the way that I had formalized the shombie argument, which I reproduce here for ease of reference.

1. (~p v q) is conceivable
2. If it is conceivable then it is possible
3. if it is possible then non-materialism is false

In short his objection was that (~p v q) isn’t the right way to formalize the first premise of the argument. He had two related points to make. The first contention was that I needed a modal operator to capture the tension between the physicalist and the non-materialist. So, I would need something like [](~p v q) (which is equivalent to ~<>(p & ~ q)). But of course I do not want to do this at all! That would make premise one totally inconceivable. I really do not think I am able to conceive of the entire space of possible worlds and see that this is true in each of them. In fact Dave makes much the same point in his 2D argument against Materialism paper against a similar move made by Yablo. All that is needed in premise one is that it is conceivable that consciousness is physical at one possible world, not all of them!

This brings up his second objection, which was that (~p v q) is conceivable but in a way that doesn’t license the inference in premise three. So, one can easily conceive of someone being conscious, and so conceive of that person being conscious or our physics being false. But this misses the point of premise one. It is not merely that (~p v q) is conceivable. Rather the claim is that I can conceive of this being true of my physical duplicate. Since we know that ~p is false at this world (we are considering a physical duplicate of me in a world that duplicates our completed physics so p must be true) it has to be the case that q is true. That is just to say that this physical duplicate of me has consciousness in just the way that I do. What is key here is that this world merely duplicates our completed physics. So, it is no good to object that this would be true in a world where there are Cartesian spirits plus our physics (as David Pitt did). That world has more in it than our physics but the shombie world, and hence my shombie twin, has just our physics.

Given all of this premise one should perhaps be re-worded as 1′.

1′. A mere physical duplicate of me, of which (~p v q) is true, is conceivable

But of course I do agree that physicalism is the thesis which holds [](p –> q). The only point I have been making above is that I do not need to include the modal operator in the first premise, which is a premise about what is conceivable. I do not need to conceive of a necessary truth in order to conceive of a shombie: that is the crucial point. The necessity comes from an independent argument that identities, if true, are necessarily true. This is the role that Kripke’s argument is playing. It is that argument which should convince us that it is necessary that the physical facts entail the qualitative facts. Given this I should probably state the third premise as 3′.

3′. If shombies are possible then, if identities are necessary then non-materialism is false.

So, summing up, we can state the more explicit 2D argument against non-materialism as follows.

1′. A mere physical duplicate of me, of which (~p v q) is true, is conceivable
2. If it is conceivable then it is possible
3′ If it is possible then, if identities are necessary then non-materialism is false.
4. identities, if true, are necessarily true
5. Non-Materialism is false

There is more that I want to say (and more interesting questions and issues raised in the discussion) but I will have to come back to it later.