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

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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!

Southern Fried Spring Phenomenology

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Winter is winding down and I am prepping for my Southern Fried Spring Phenomenology tour.

1st stop is the Southern Society for Philosophy and Psychology March 22-24 in Savannah Georgia, where I will be commenting on Benji Kozuch’s paper (on lesions to the prefrontal lobes and the implications for higher-order theories), as well as giving a talk in an invited symposium “Explaining Consciousness” (with Josh Weisberg and Kenneth Williford); “Phenomenal Consciousness Ain’t in the (Back of the) Head”. I am putting the final touches on the presentation and hope to record a practice run of it sometime this week (look for it on my YouTube channel). This conference should be a lot of fun since it seems like I know everyone on the program! Kudos to Pete Mandik for assembling such a great group of people!

2nd stop back to New York for Funkomenological Overflow at the Local 269 Tuesday April 3rd. This free event in lower Manhattan features the music of the Space Clamps, the return of Quiet Karate Reflex, and the William James Trio…all three of these groups feature me on the drums! We have been rehearsing a lot and each group has a unique sound and set list…where else can you find jazz/funk, 8bit experimental breakbeats, and funk/awesome rock played by philosophers, neuroscientists, and psychologists?

3rd stop is back to the south for the Tenth Biennial Towards a Science of Consciousness conference in Tucson (ok, ok, so that’s a different south, but c’mon!). I will be giving a talk in the Dualism and Modal Arguments concurrent session which will be a ‘all-things-considered’ statement of my 2D argument against Non-Materialism. I haven’t been to Tucson since 2008 so I am really looking forward to it!

Hope to see you on the road!

The Overflow Cup Runneth Over

Richard Brown 4 Comments

There has been a lot of action on the overflow front lately! It started with papers by Ned Block and Dennett and Cohen in Trends in Cognitive Science (Block’s paper criticized, among others, my recent paper on this stuff). These articles spawned a response by me here and here, which I still stand by.

But now, having read the response from Kouider (which echoes his response given at his CUNY Cogsci talk) as well as the response from Overgaard and Block’s response to both of them in addition to Lamme’s response to Cohen and Dennett and their response in turn, it seems a couple points should be emphasized.

Accessed vs. Accessible
Block again and again says that his argument does not depend on inaccessible consciousness but rather on it being necessary that at any given moment there is some consciousness that is not accessed (but could be accessed at a different moment and so is not inaccessible tout court). There seem to me to be several issues worth considering here.

First is that there is a conceptual question about what it means to say that something is accessible but not accessed. One might think that you cannot know that something is accessible without it actually being accessed. Block and others respond that something is accessible when, roughly, it is globally broadcast. But then we might wonder why we ought to think that being globally broadcast is equivalent to being accessible. Aren’t their mental contents/states that are globally broadcast but which are not accessible? David Rosenthal has pressed this kind of question in conversation and I am not exactly sure what the neuropsychological answer is in this case. Is there any serious neuropsychological reason to think that global broadcasting is equivalent to being accessible?

Second one might worry about the ‘thin edge of the wedge’ implications of Block’s argument. If we can show that there is consciousness that is not accessed then it seems a short step to consciousness that is inaccessible in principle. And if it is true that there is a principled connection between the two then though it would be strictly speaking true that Block’s argument did not rely on inaccessible consciousness it would none the less still be appropriate to give a reductio of his argued for view in terms of absurdities in the view it leads to.

Finally, it does seem as though there is a principled connection between the two notions. Block argues that it is inappropriate to argue against the claim that there is inaccessible consciousness because he only requires that some consciousness not be accessed not inaccessible. But if one thinks just of a particular moment in consciousness leaving aside the next moment it is of course true that some consciousness is inaccessible. It is inaccessible at that moment. Block’s view is that at any given moment in your daily conscious experience there is, necessarily, some parts of your conscious experience that are inaccessible at that moment. Because of this his view really does have all of the problems associated with in principle inaccessible consciousness.

Given these considerations I don’t think that the appeal to the distinction between not accessed and inaccessible helps make Block’s case.

Kouider’s Data Count Against His Own View?
Block has said several times that Kouider’s own data counts against the no-overflow view. He says in his latest response,

According to the hypothesis Kouider et al. put forward, what is in consciousness before the cue are generic representations plus specific representations that are too sparse to provide the information necessary to explain partial report superiority. However, on their hypothesis one would expect a substantial error rate concerning the uncued items. However, Kouider et al. found the error rate to be small: their own evidence counts against them.

It really is not clear to me why Block thinks that one would expect a substantial error rate concerning the uncued items. He seems to be thinking that the no-overflow view is committed to only generic phenomenology before the cue but this is clearly not the case. It is compatible with the no overflow view that there is some specific phenomenology before the cue (just not all of the items as per overflow).

But even if one is not moved by this there is an obvious problem with the argument. The no overflow position maintains that there is enough information unconsciously processed to do the task. Subjects don’t make a lot of errors because that information was there whether consciously or not.

Falsifiability vs. Support by the Evidence
I think that Block is right that we do not want falsifiability as a=our standard here and that we need to evaluate theories holistically based on the widest swath of available evidence and theories available to us. Block thinks that there is some evidence that the kinds of unconscious processes necessary to sustain the no overflow view aren’t there. But this evidence is very weak and the jury is still out on this issue. In general the science is all over the place on this issue. There is partial evidence on both sides and no theory comes out on top on the basis of current scientific evidence alone. Hopefully this will change in the nearish future but at this point this is where it is.

Given this one might think that we should be agnostic about whether overflow is true or not but this doesn’t seem right to me. The overflow hypothesis is radical in that it postulates a kind of consciousness that cannot in principle be accessed (at that moment) and yet which is also for me in the way that normal accessed consciousness is for me. That is, I experience the unaccessed consciousness as mine without being aware that I do. How this could be so is deeply mysterious and perhaps in principle untestable with any known scientific methods. Barring prejudice in its favor we would need strong evidence indeed to accept such a notion.

Explaining Cartesian Consciousness

Richard Brown 2 Comments

In his classic paper “Two Concepts of Consciousness” David Rosenthal says “…if consciousness is essential to mentality no informative, nontrivial explanation of consciousness is possible” (2005 p 22). The claim is, roughly, that if all mental states are conscious and if there are no mental states that can occur unconsciously, then we cannot explain what makes a mental state conscious. But this assumes a certain way of characterizing the claim that all mental states are consciousness.

In a really excellent paper that just came out in Philosophers’ Imprint by Allison Simmons, Cartesian Consciousness Reconsidered, she argues that Descartes’ can understand consciousness as a kind of self-representation and can account for ‘unconscious’ mental states by appealing to gradations of consciousness and what she calls ‘phenomenal confusion’. I think she makes an excellent case that a Cartesian picture of the mind can go a long way towards providing an explanation of conscious and (seeming) unconscious states.

Yet even so, I think we can see that the initial claim made by Rosenthal is still true in a sense. The Cartesian moves made by Simmons all rely on a prior account of mentality. That is, the Cartesian explanation given relies on a prior understanding of sensations (as having objects as their ‘objective reality’, which we would translate as ‘having representational content’) and explains consciousness in terms of a thought having as it objective reality a first-order state (i.e. consciousness is the representation of our first-order states). In fact Simmons seems to make much the same point in her paper. If we interpret Descartes as claiming that thoughts and consciousness are identical then we will not be able to explain it. But, as she shows, this is not something that a Cartesian is committed to. So even if one is attracted to the view that all mental states are conscious one doesn’t need to give up on an explanation of what consciousness is.

Kant on Suicide

Richard Brown 5 Comments

I am no Kant scholar (thankfully!) but I do regularly teach ethics and so am constantly re-reading the Groundwork of the Metaphysics of Morals. I have never really known what to think about Kant’s argument in the section where he is discussing the formula of the law of nature and how it applies to suicide. Here is what he says:

…[the] maxim…is: from Self-love I make it my principle of action to shorten my life when its longer duration threatens more troubles than it promises agreeableness. The only further question is whether this principle of self-love could become a universal law of nature. It is then seen at once that a nature whose law it would be to destroy life itself by means of the same feeling whose destination is to impel toward the furtherance of life would contradict itself and would not therefore subsist as nature…

I have always interpreted this passage as expressing some kind of natural law theory rather than a deliverance of the categorical imperative. The function or role of self-love is the preservation of life. Using it in this way violates that natural function and so results in a contradiction of a sort but not the usual sort you find in the case of perfect duties. Of course the flaw in that reasoning is that it is not obvious why it must be the case that to use something contrary to its function is immoral (is it immoral to use a butter knife to screw in a screw?).

For full disclosure, I take myself to be a Kantian of a sort, though I would probably not be viewed as an orthodox Kantian (I, for instance, think we can derive Utilitarianism from the Categorical Imperative (like Hare did as well) and I think we can derive duties towards animals in much the same way). And I also take it that suicide is morally permissible in at least some cases and so I have always been happy to see something odd about Kant’s argument against suicide.  Yet today in class I found myself wondering whether this natural-law-remnant theory is the most charitable reading of that passage.

In the case of the other perfect duties we seem to find a pattern where in the imagined world the very thing that we are trying to do becomes impossible. Thus in the lying promise case the very act of making a promise becomes impossible. Since we cannot be coherently described as promising in a world where everyone makes lying promises we arrive at a contradiction. So, too, in the case of lying in general. In a world where everyone lies to avoid discomfort lying itself is impossible. So too for stealing. In a world where everyone steals stealing is itself impossible (since there is no ownership in such worlds and when we steal we take ourselves to be owners). So if we are to extend this general line to what Kant says here then it must somehow be the case that in the world where the maxim in question is a universal law suicide itself is impossible.

This seems implausible but it might not be. Suicide is the act of taking one’s life out of self-love. If self-love is itself not possible then suicide is not possible. So maybe what Kant had in mind was that self-love is by definition the thing which impels us towards life and so in the suicide-maxim world there is no self-love since there is no universal drive towards life, but rather only a limited drive towards life-as-long-as-it-is-agreeable or some such. Since there is no self-love there can be no suicide (which requires that you act from self-love). This would still be a questionable argument (since the limited thing still seems like self-love enough to do its job in ‘normal’ circumstances) but might be a more fair way of reading Kant’s claim in the above passage.

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