Philosophy of Mind

Recent Events

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Well, the semester at LaGuardia is finally coming to a close (our schedule is out of step with the rest of CUNY). A lot has been going on and I have barely had time to do anything but since today is our reading day and I have a brief break before final exams come in, I thought I would quickly talk about what has been going on.

My new course, Cosmology, Consciousness, and Computation was a huge success and the students really seemed to enjoy the chance to take these kinds of questions seriously. The basic idea behind the course is to explore issues related to physicalism but after a grounding in the actual physics. My experiment to use the Stanford Encyclopedia as a primary text seemed to work ok as well. Some of the readings are fairly technical but I gave students the choice of which to read and which to write a one page summary/reaction to. They also seemed to like the Terminator book, which was nice. This is the first time I have used it in a class. I am toying with the idea of maybe recording the lectures for this course over the summer as I prepare to teach it again next semester (but I am also teaching philosophy of religion and ethics over the summer and I am tempted to record my philosophy of religion as well…they do overlap a bit so maybe I’ll do both!). For those interested, here is the syllabus. As with any new class I expect to update a lot of it in light of what happened this semester and any feedback would be appreciated.

All of that will have to wait until later in July, though, since I am currently getting ready for my trip to San Diego for the 17th meeting of the Association for the Scientific Study of Consciousness (ASSC). This year I have organized a symposium on the Role of the Prefrontal Cortex in Conscious Experience. The speakers are Rafi Malach, Joe Levine, Doby Rahnev, and myself. I am really looking forward to it, as well as to the rest of the program! I am hoping to post a video of my talk in the nearish future.

I have also been working on a new paper, which came out of discussion at the 5th Online Consciousness Conference. It is entitled Consciousness is (Probably) a Biological Phenomenon. Those who know me know that I am attracted to an identity theory when it comes to consciousness and that I harbor the suspicion that consciousness is a uniquely biological phenomenon. This paper is my first attempt to spell out an answer to Chalmers’ fading and dancing qualia arguments using empirical results (in particular the partial report results that have figured in the overflow debate (see here and here)). It is extremely drafty (I have been working on it an hour here and hour there for the last few weeks) and any feedback would be much appreciated.

In addition to all of this I have just returned from my trip to the Omaha Kripke Conference (during which I was also on my first dissertation committee at the Grad Center, which was very much fun but then I also had to read and think about a dissertation!), which was a really rewarding experience. Omaha is a wonderful town and the conference itself was excellent, if exhausting. Three days of excellent papers and excellent discussion, and it was very cool to see Saul so active and engaging with the material. Unfortunately, due to bad weather, he came late and so he missed my talk but there was none the less a lot of very helpful discussion. The main objection was Dan Shargel’s ‘hierarchy objection’ which he presented at Tucson last year (the basic idea is that we can move the argument up to the level of appearance and imagine that we have that appearance without the neural state, etc). I have got to get better at explaining what my answer to that objection is. After the discussion at the conference I have come to think that the main problem is that we are using ‘how pain appears to me’ as a way to pick out two different states, one a psychological state and the other a neural state. On the one hand we use it to pick out the pain sensations, that is the first-order sensing of bodily damage. But we can also use it to pick out the neural state that the appearance is identical to (note: not the neural state that the sensation is identical to, but the neural state that is identical to the awful painfulness appearance. We can use the appearance property as a way to pick out that state itself). It is in that second sense that we avoid the charge of regress. This takes some spelling out to make sense of it and I am hoping to write something more detailed on it in the nearish future (hopefully before I head out to the ASSC).

During and after one of the other sessions I had the chance to talk to Saul about his 1963 paper Semantical Considerations on Modal Logic, which I have discussed previously on the blog. When I suggested that it was a cost to one’s theory to give up logical constants in your quantified modal logic he insisted that it was not. This was because for any sentence with a logical constant in it we could translate it into a sentence without the constant without loss of meaning using Quine’s trick of inventing a predicate. This led me to wonder whether this made it the case that we could reformulate the bothersome proofs using translated sentences. At the time I wasn’t able to come with a way to do this but once I got home I thought about it a bit more and came up with the following.

In the original reductio we used this sentences ☐∃x(x=k), where this is read as ‘there exists an x such that x is identical to Saul Kripke’. How would we translate this sentence to get rid of the constant? We would replace the constant with a predicate, say ‘K’ (‘the Kripisizer’) and thus we would get ☐∃x(x=Ky) but this has a free variable in it so we would have to take it as asserting the ‘closed’ version, so we get ∀y☐∃x(x=Ky). We can then proceed to prove this in the same way as before using a reductio

1. ~∀y☐∃x(x=Ky) -assumption for reductio
2. ∃y~☐∃x(x=Ky) -1, quantifier exchange
3. ∃y◊~∃x(x=Ky) -2, definition of ☐
4. ∃y◊∀x~(x=Ky) -3, quantifier exchange
5. ∃y◊~(Ky=Ky) -Universal instantiation on 4
6. ∀y☐(Ky=Ky) -instance of axiom of identity
7. ~∃y~☐(Ky=Ky) -6, quantifier exchange
8. ~∃y◊~(Ky=Ky) -7, definition of ☐
9. ∃y◊~(Ky=Ky) & ~∃y◊~(Ky=Ky) -4,8 -conjunction introduction
10. ∀y☐∃x(x=Ky) -1-9 reduction

I think the main issue with this reformulated proof is line 5 when I use ‘Ky’ as an instance of x in 4. It seems to me that this move should be allowed, though. This is because part of the whole point of the 1963 paper was that we could block these kinds of proofs and still keep our traditional quantification theory. So we should be able to use UI, but if we are not allowed the use of constants then we will have to use predicates, which is what I did. Also, the variable in 5 is not free and is bound by the existential quantifier. So all in all I think this reformulated proof works but I really haven’t had the time to think about it very carefully.

Well that is enough for now…time to head over to Brains to read some of the commentaries in the Symposium on Louise Richardson’s “Flavor, Taste and Smell”.

Peter Godfrey-Smith on Evolution And Memory

Richard Brown 1 Comment

On friday I attended the first session of the CUNY Cognitive Science Speaker Series. The talk seemed to me to be based largely on this paper. I only have a few moments but I thought I would jot down the gist of the talk while it is fresh in my mind.

Godfrey-Smith wanted to take the ‘sender-receiver’ model of communication develop by David Lewis and apply it to debates about memory. On the Lewis model we have a sender that has access to a part of the world that the receiver does not, a sign that is passed between them, and a receiver that is able to take the sign and produce an action. Godfrey-Smith’s guiding idea is that when you have this kind of set up in the psychology of an organism and the signaling takes place over time, then you have memory.

One of the main points he wanted to make in the first half of his talk was that the idea of episodic memory as ‘constructive’ does not show that one of the main functions of episodic memory is to be truth preserving. He was aiming to oppose a group of scientist working on memory who hold what he called the ;future first’ hypothesis about episodic memory. Roughly speaking the idea is this. Our ability to imagine future events, and their outcomes is crucial for us and gives us an evolutionary advantage against those that cannot do it. What we have found out is that the neural areas that underlie our ability to do this are also largely the same ones involved in our ability to remember our past experiences. The ‘future first’ hypothesis is the idea that our ability to remember our own past experiences is simply a by-product of our ability to imagine future events and their outcomes. This is supposed to be further supported by the fact that episodic memory is thought of as ‘constructive’ in the sense that it is often wrong about the details of past experiences and tends to ‘construct’ memories along the most likely scenarios. Godfrey-Smith argued that if we think of memory in terms of the sender-receiver model then we should not immediately expect that the contrastive nature of episodic memory means that it is not truth-tracking. It is perfectly conceivable that the senders produce truth-tracking representations and that the receivers, who may be a bit smarter, ‘improvise’ from there. We can then go on and ask just how much deviation from the facts there is in the sender’s signal.

In the second half of his talk he went to discuss the controversy in cognitive science of whether there is any kind of reader in the brain. That is, is there anything in the brain which is akin to the ‘head’ in a turing machine. Something which interprets whatever message has been sent by the sender. He argued that the dominant view in the sciences is that there is no such reader. Godfrey-Smith went on to argue that there must be a reader, but that there is no sender. DNA, for instance, on this view is not an instance of information being sent. It is information, that happens to be able to be read (as a result of natural selection), but it has not been ‘written’ because, to put it crudely, nothing had the purpose of sending the message. In discussion he wanted to back away from talk of intention and purpose as ‘shorthand’ for the longer answer but I couldn’t make out what the longer answer was supposed to be.

Zombies vs Shombies

Richard Brown 2 Comments

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

Richard Brown 17 Comments

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.

The Brain and its States

Richard Brown 1 Comment

Some time ago I was invited to contribute a paper to a forthcoming volume entitled Being in Time: Dynamical Models of Phenomenal Experience. I was pleasantly surprised to find out that I was invited because of my paper “What is a Brain State?” Looking back at that paper, which I was writing in 2004-2005, I was interested in questions about the Identity Theory and not so much about consciousness per se and I wished I had said something relating the thesis there to various notions of consciousness. So I was happy to take this opportunity to put together a general statement of my current views on this stuff as well as a chance to develop some of my recent views about higher-order theories. Overall I think it is a fairly decent statement of my considered opinion on the home of consciousness in the brain. Any comments or feedback is greatly appreciated!

Clip Show ‘011

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It’s that time of year again! Here are the top posts of 2011 (see last year’s clip show and the best of all time)

–Runner Up– News Flash: Philosophy Sucks!

Philosophy is unavoidable; that is part of why it sucks!

10. Epiphenomenalism and Russellian Monism

Is Russellian Monism committed to epiphenomenalism about consciousness? Dave Chalmers argues that it is not.

9. Bennett on Non-Reductive Physicalism

Karen Bennett argues that the causal exclusion argument provides an argument for physicalism and that non-reductive physicalism is not ruled out by it. I argue that she is wrong and that the causal exclusion argument does cut against non-reductive physicalism.

8. The Zombie Argument Requires Phenomenal Transparency

Chalmers argues that the zombie argument goes through even without an appeal to the claim that the primary and secondary intension of ‘consciousness’ coincide. I argue that it doesn’t. Without an appeal to transparency we cannot secure the first premise of the zombie argument.

7. The Problem of Zombie Minds

Does conceiving of zombies require that we be able to know that zombies lack consciousness? It seems like we can’t know this so there may be a problem conceiving of zombies. I came to be convinced that this isn’t quite right, but still a good post (plus I think we can use the response here in a way that helps the physicalist who wants to say that the truth of physicalism is conceivable…more on that later, though)

6. Stazicker on Attention and Mental Paint

Can we have phenomenology that is indeterminate? James Stazicker thinks so.

5. Consciousness Studies in 1000 words (more) or less

I was asked to write a short piece highlighting some of the major figures and debates in the philosophical study of consciousness for an intro textbook. This is what I came up with

4. Cohen and Dennett’s Perfect Experiment

Dennett’s response to the overflow argument and why I think it isn’t very good

3. My Musical Autobiography

This was big year for me in that I came into possession of some long-lost recordings of my death metal band from the 1990’s as well as some pictures. This prompted me to write up a brief autobiography of my musical ‘career’

2. You might be a Philosopher

A collection of philosophical jokes that I wrote plus some others that were prompted by mine.

1. Phenomenally HOT

Some reflections on Ned Block and Jake Berger’s response to my claim that higher-order thoughts just are phenomenal consciousness

The Myth of Phenomenological Overflow

Richard Brown 4 Comments

Update 7/27/11
The paper is now available on Consciousness and Cognition’s website: The Myth Of Phenomenological Overflow
————

I have just finished my contribution to the Special Issue of Consciousness and Cognition that I am editing featuring descendants of papers from the second online consciousness conference and made the pre-print available at my PhilPapers profile. Discussion and comments are welcome.

The Myth of Phenomenological Overflow

Abstract:
In this paper I examine the dispute between Hakwan Lau, Ned Block, and David Rosenthal over the extent to which empirical results can help us decide between first-order and higher-order theories of consciousness. What emerges from this is an overall argument to the best explanation against the first-order view of consciousness and the dispelling of the mythological notion of phenomenological overflow that comes with it.

Can We Think About Non-Existent Objects?

Richard Brown 8 Comments

I am scheduled to record a conversation with Pete Mandik for Philosophy TV tomorrow on higher-order approaches to consciousness and in the course of preparing for it I was rereading Pete’s Unicorn paper where, among other things, Pete gives several arguments that we are in fact able to think about non-existent objects. I do not think that we can.

It may seem quite natural to think that the answer to the above question is ‘yes’. For instance, we think of Count Dracula, unicorns, Santa Claus, and many other examples of this kind. If we take ‘thinking about’ to involve having some kind of relationship with the thing that is thought about this can seem crazy. If I am thinking about Santa Claus, for instance, that would mean that there would have to be some object that I was related to and since Santa doesn’t exist the object would seem to be a very strange one indeed! What should we conclude from this? Should we conclude that ‘thinking about’ doesn’t really involve a relationship between the thinker and the thing thought about?

Suppose that one accepted some kind of causal-historical account of the reference of (at least some of) our concepts and that thinking about x means tokening a thought containing a mental representation of x with the approriate causal-historical connection to x. So, to rehearse a familiar picture, Some child is born, his parents say “let’s call him  ‘Saul Kripke'”, other people are told “this is Saul Kripke” and thereby acquire the ability to refer to this child. Over time this name propagates, like a chain, link by link to us. So that when I think about Saul Kripke I employ a thought token that traces a causal-historical route back to the initial “baptism”. If this were the case, and one thought that natural kind terms worked like this as well, one would end up denying that we think about non-existent objects. The concept UNICORN has as its reference whatever it is that actually turns out to have been “baptized”. This may turn out to be a deformed goat, a hallucination, or maybe an imaginative act on the part of a person, whatever it actually turns out to be is what we are thinking about when we think about unicorns and that thing exists. So too for Dracula, Santa Claus, Jackalopes, etc.

But what about when we think thoughts like ‘there are no square circles’? Aren’t we thinking about square circles? I don’t think we are. Rather I think we are having an existentially quantified thought to the effect that nothing is both square and circular at the same time. Aha! Aren’t existentially quantified statements that are actually false examples of thinking about non-existent objects? If I think that the present King of France is bald, and there is no present King of France, are not I thinking about a non-existent object? Of course not! What you are thinking is that there is someone or other who is the present King of France and that is just plain, ordinary, boring false. There is no non-existent object which is correctly described as the one you are thinking about.

But isn’t denying that we can think about non-existent objects self refuting? What have we been talking about this whole time if not whether or not there are any of this kind of thought! So denying that there are any just shows that we have been thinking about non-existent objects all along! The very thoughts about non-existent objects that we have been discussing. But this is too quick. This is again just another example of an existentially quantified statement. ‘There are no thoughts about non-existent objects’ is really just saying that thoughts about non-existent objects don’t exist but that does not thereby mean that I am thinking about some non-existent objects! And this is for just the same reason as above; there are no objects which can be correctly described as the ones that I am thinking about.

So I am inclined to deny that we can think about non-existent objects…I am not saying that everyone should but only that there is a reasonable view, one that we ought to accept for other reasons not gone into here, and which denies that we think about non-existent objects. What this has to do with consciousness and Pete’s unicorn argument I will save for tomorrow’s discussion.

Zombies and Impossible Worlds

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Via Leiter’s blog I happened to be looking at the list of recent SEP entries. I read this entry on impossible worlds that got me thinking.

The response to the zombie argument that I have been developing over the last couple of year appeals to the distinction between prima facie and ideal conceivability. Something is prima facie conceivable, roughly, if there is no obvious contradiction in the imagined scenario. Something is ideally conceivable if, roughly, there is no contradiction in the imagined scenario even upon ideal reflection. I have tried to argue that zombies are merely prima facie conceivable and may not turn out to be ideally conceivable (another way of putting it that is roughly equivalent is that zombies are epistemically possible but not metaphysically possible) since there are equally plausible parity arguments (zoombies and shombies). As a corollary of this line of defense I have argued that what people like Dave actually succeed in imagining when they *think* they imagine the zombie world is really just a world that is very similar to the actual world. Just as a point of clarification I have always meant this to be a different claim than the Russellian response that the zombie world may have different ‘inscrutable’ fundamental physical properties. What I mean is that since we do not yet know all of the facts about the brain, physics, or theories of consciousness, we may be inadvertently failing to include some crucial physical law, property, or theory of consciousness. So it is very easy, I claim, to imagine a world that is physical in roughly the same sense that ours is but where there is no consciousness. For instance, if the higher-order thought theory of consciousness is right then the ‘zombie’ world is really just a world like ours that lacks higher-order thoughts.

Now people like Dave often claim that they can conceive that we add this feature and yet still it is intuitive that those creature could lack consciousness. If this is really the case and the higher-order theory is true then Dave has imagined an impossible world. But it seems to me that we can at this point admit that the traditional zombie world is conceivable and go on to argue for a restriction on the second premise of zombie argument, which to remind us, is the claim that if zombie are conceivable then they are possible. This premise becomes possibly false since it may be the case that zombies are conceivable but not metaphysically possible, where this means that they inhabit an impossible world.

One response to this line of thought might be that the use of ‘conceivability’ here isn’t the same as that employed by the zombie argument. As used by Dave ‘conceivable’ means roughly imaginable without contradiction but in these impossible worlds we conceive of a world with a contradiction (by stipulation it contains a contradiction). But, of course, the point here is that one may not notice or be in a position to spot the contradiction, which is exactly one of the reasons for postulating impossible worlds (or in this case impossible scenarios in Dave’s sense). If one takes this line, as I am inclined to do myself, then the issue reduces to the original one of the difference between prima facie conceivability and ideal conceivability. But if one has a more generic version of conceivability one can argue that zombies are conceivable and impossible in way that seems different from the usual type-b line…