Swamp Thing About Mary

Richard Brown 5 Comments

On Friday I attended Pete Mandik’s Cogsci talk at CUNY. The talk was excellent; entertaining and with a spirited discussion of many interesting topics. This paper represents one of a two part project that Pete is pursuing that involves Swamp Mary. One project employs Swamp Mary against dualists while the other employs her in an in-house dispute between what Pete call ‘gappy’ and ‘non-gappy’ physicalism. Friday’s talk was the latter and is based on his paper Swamp Mary Semantics: A Case for Physicalism without Gaps.

Pete’s distinction is recognizable as meant to capture type-a and type-b physicalism. More generally it is the distinction between a priori and a posteriori phsyicalism. Or at least one may get that idea from the way Pete characterizes the distinction. He says that the issue is over whether or not what we can “classic Mary” in her pre-release condition is in a position to know what it is like to see red. Pete claims that the gappy physicalist will deny that she does while the non-gappy physicalist does not. Swamp Mary is then presented as a challenge to the gappy physicalist. In short the challenge goes as follows. Swamp Mary is a physical duplicate of post-release Mary, the one who has seen red and so knows what it is like to see red, but Swamp Mary has never herself seen red since she is a swamp being who, we can stipulate, has had no experiences herself at all. She is a duplicate of a being that has had the experience of seeing red but hasn’t herself had the experience. Nonetheless, Pete urges, it is natural to say that Swamp Mary knows what it is like to see red. This is natural since post-release Mary knows what it is like to see red and Swamp Mary is a physical duplicate of post-release Mary. But since it is also natural to say that Swamp Mary has never seen red, or had an occurrent red quale, it is now mysterious why it is supposed to be the case the pre-release Mary doesn’t know what it is like to see red. If Swamp Mary can know what it is like to see red without ever having a red quale then it ought to be the case that pre-release Mary can also know what it is like to see red without having seen it. Thus, Pete concludes, physicalist should be non-gappy physicalist and hold that Mary can know what it is like to see red in her pre-release state.

Pete then goes through various responses that might be made by the type-b physicalist and tries to show that they all have problems. He does this by examining four different psychosemantic theories, which he also claims to be exhaustive, and arguing that they cannot provide the relevant explanation (i.e. of the difference between pre-release Mary and Swamp Mary’s knowledge of what it is like to see red). The four categories of psychosemantic theory are: 1. Quotation 2. Actual Cause 3. Nomological 4. Descriptive-homomorphic/isomorphic. Briefly, 1 is supposed to capture any kind of self-presentational view about phenomanl concepts like that of Chalmers or perhaps Block. 2 is supposed to capture any kind of teleological or causal theory of content while 3 is supposed to capture anything that resembles Fodor’s psychosemantics (think ‘asymmetric dependance’ here). Finally, 4 is supposed to capture any kind of conceptual role kind of theory. The problems for each of these, to make a long story short, are that 1 and 2 cannot explain how Swamp Mary does know what it is like to see red while 3 & 4 end up having problems explaining why pre-release Mary doesn’t know what it is like to see red.

There is a lot of detail that I am leaving out but in general Pete is trying to construct an argument against a central claim of the type-b physicalist. This is the intuition, shared by many, that one cannot really have the full concept RED without having the red quale present in ones consciousness. Or to put it more common sensically, one cannot know what it is like to see red unless one has (a) had a red experience and (b) has the ability to think, or otherwise identify, that the experience is red while one is having it. Pete has the intuition that Swamp Mary knows what it is like to see red and yet neither (a) nor (b) seem to be met and therefore concludes that the type-b physicalist is wrong. I suggested in discussion that Pete was running over the distinction between ‘knowing what it is like’ in the general sense, and ‘knowing what it is like FOR one’. To know what it is like for one too see red requires that one have, or be able to recall, a red experience and to be able to say, so to speak, to one’s self ‘this is what it is like to see red’. To know what it is like in the generic sense is to know what it is like to see red in the way that pre-release Mary is typically thought of by the type-b physicalist. She can know a lot about what it is like to see red. She can know that it is more like seeing something pink than it is like seeing blue, and all other kinds of facts. But intuitively she doesn’t know what it is like for her to see red. Once we have this distinction in mind we no longer have a problem with Swamp Mary. Swamp Mary knows what it is like in the generic sense, in just the same way as pre-release Mary, but she does no know what it is like for her to have the experience, again just like pre-release Mary. To put this in different terminology, both pre-release Mary and Swamp Mary lack the “pure” phenomenal concept, though they have many others. On the other hand, if we think that Swamp Mary does know what it is like in this way it will be because she has an ability to call up the red experience and identify it, whereas Classic Mary cannot do this.

Finally, does saying this really make one a gappy/type-b phsyicalist? I claim that it doesn’t. I agree that in the way the Mary thought experiment is usually set up we arrive at the conclusion that pre-release Mary cannot know what it is like for he to see red. This is because she lacks the appropriate concept, the pure phenomenal concept. In order to acquire this concept she needs to have the experience. But once she does there is no longer any gap between the physical and phenomenal. Once Mary has the pure phenomenal concept she is able to know what it is like to see red in the complete way necessary to make deductions from physical facts to phenomenal facts without relying on the pure phenomenal concept (or introspection) for justification of any step in the deduction. Thus in order to really count as a gappy physicalist in Pete’s sense we would have to deny that even once Mary had this concept she would be unable to know what it is like for her to see red just on the basis of the physical facts. This is much less plausible to me.

After the talk at the bar we started to talk about the role that intuitions should play in philosophy. This discussion was started by thinking about the experience principle. Why does anyone think that it is true that in order to fully have the concept of red one must have seen red, or had a red experience? I claimed that have prima facie evidence for this claim from the fact that it is intuitively obvious to many philosophers. I agree, basically, with Michael Devitt’s view that intuitions, especially those of experts, should count as defeasible evidence. Thus, we can have a priori justification for believing something but not a priori knowledge in the traditional sense. The mere fact that most philosophers think that Mary couldn’t know what it was like for her to see red from within her room should count as evidence, not for epiphenomenalism or dualism, but rather for the experience principle. That is what is really being tested there. Now, I agree that this is defeasible evidence. We could come to have reason to reject the idea. I *think* I can at least negatively conceive of a situation where pre-release Mary comes to know what it is like to see red without seeing it first. She will know that when people see red they are in a certain brain state. She will also know that people talk about knowing this state in a special first-person way and that they can only do this when in the relevant brain state. She might then conclude that to know what it is like to see red in this sense requires that she be in this brain state. Since she is not allowed to have the stimulus that will produce the brain state she must find some other way to produce the brain state. She might then realize that when one imagines seeing red one goes into something like the brain state that one is in when one actually sees red. Could she come to token this brain state without the stimulus? Well, obviously she could rig some kind of autobrain stimulation to stimulate the area and produce the experience. But is it absurd to think that she could do this without brain stimulation? That is, could she imagine what red looked liked without ever having seen it? I am not sure…my intuitions tend to go with the experience principle but I can’t see anything contradictory about the scenario just described…

There is more to say about all of this but this is getting too long already!

Two Ways to (Not) Think About Unicorns

Richard Brown 3 Comments

Listening back to the discussion Pete and I had, as well as my previous post on this stuff, and something occurred to me. There really are two different ways of thinking about the concept “unicorn”. One way is the way that I have been thinking about it ad that is as a regular natural kind term like ‘horse’, ‘tiger’, etc. Concepts like this, according to me, are best treated along the lines of a causal-historical account like the Kripkean inspired theory that Devitt produced. But there is another way of thinking about unicorn, one that thinks of it as like ‘bachelor’ rather than ‘tiger’. Terms like that are best treated in terms of a conceptual-role theory. So, it is the relations between the concept ‘bachelor’, ‘unmarried’, and ‘male’ that makes my thought that all bachelors are unmarried males true. If one thought about ‘unicorn’ like this, one might think that it is the conceptual relations between ‘unicorn’, ‘horse’, and ‘horn’ have that make it the case that when I am thinking about unicorns I am thinking about horned horses. That is, one might think of the concept ‘unicorn’ as being defined as ‘horse with a horn’. Now, it seems to me that we employ both kinds of representations in thought so then the question becomes one of which kind features in the content of higher-order thoughts. I claim that it is the former and not the latter and that that matters.

cfp: 3rd Online Consciousness Conference

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Please post and distribute widely; apologies for cross-posting.

I am pleased to announce the call for papers for the third online consciousness conference. Invited speakers include,

Kathleen Akins, Simon Fraiser University

Paul Churchland, University of California San Diego

Steven Harnad, University of South Hampton

Jesse Prinz, The Graduate Center, CUNY

Papers in any area of consciousness studies are welcome, though the conference has as its theme this year ‘Neurophilosophy and the Philosophy of Neuroscience’. Selected papers from the conference relating to this theme, pending outside review, will be published in the annual special issue of Synthese “Neuroscience and its Philosophy”. Because of this contributions that are unpublished elsewhere and related to the theme are preferred, though exceptions can be made.

Papers should be roughly 3,000-4,000 words and subsequent presentations, should the presenter choose to make one, should be about 20 minutes (though longer papers/presentations are acceptable). Submissions, suitable for blind review, should be sent to consciousnessonline@gmail.com by January 5th 2011. Those interested in being referees or commentators should also contact me. Authors of accepted papers are urged to make, or have made, some kind of audio/visual presentation (e.g. narrated powerpoint or video of talk) though this is not required to present.

For more information visit the conference website: http://consciousnessonline.wordpress.com

More Square

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As I mentioned in my last post we are discussing the traditional vs modern square of opposition in my logic course (which did not go over well btw, most students reacted viscerally to the claim that modern logicians reject the entailment of the I proposition by the A proposition…to the point that one student exclaimed that it was a betrayal of Aristotle!) but at any rate I was reading the entry at the Stanford Encyclopedia on the Traditional Square of Opposition which is written by Terrance Parsons. The article is very interesting and provides a valuable history of the development of the square.

Along the way Parsons develops the very interesting idea that the modern problem with empty terms is not a problem for Aristotle’s original formulation of the square and especially because of the way he formulated the O statement, which is not as the traditional ‘some A is not B’ but rather is ‘Not every A is B’. This, argues Parsons, solves the problem with existential import since ‘not every A is B’ does in fact seem to be true as is required. Parsons blames Boethius for the rewording of the O form,

Aristotle’s work was made available to the Latin west principally via Boethius’s translations and commentaries, written a bit after 500 CE. In his translation of De interpretatione, Boethius preserves Aristotle’s wording of the O form as “Not every man is white.” But when Boethius comments on this text he illustrates Aristotle’s doctrine with the now-famous diagram, and he uses the wording ‘Some man is not just’. So this must have seemed to him to be a natural equivalent in Latin. It looks odd to us in English, but he wasn’t bothered by it.

But isn’t it obvious that ‘not every unicorn is an animal’ is truth-functionally equivalent to the traditional ‘some unicorn is not an animal’? That is to say, it is clearly the case that ~(x) (Hx –> Mx) is equivalent to Ex (Hx & ~ Mx) [by quantifier exchange, the definition of ‘–>’ and DeMorgan’s law]. So…Boethius was right, wasn’t he? And not just because it is a natural translation in Latin, but because the two statements are logically equivalent….right?

Does All Imply Some?

Richard Brown 9 Comments

So in the logic course I am currently teaching we are about to start talking about the contrast between the modern and traditional square of opposition. The main difference, of course, is that poor Aristotle thought that if it was true that All A’s are B’s that made it the case that Some particular A was in fact B, and so he would be forced to exclude syllogisms as valid that have fictional terms. Consider the following proposition,

1. Some humans are mammals

Now, I often find that students think that 1 is false. They think that it is false because they think that it implies 2

2. Some humans are not mammals

but in the traditional square of opposition this is not the case. 1 and 2 are subcontraries, which means that they can’t both be false. Now this means that it is a possibility that both of them are true, but there is also the possibility that only one of them is true and the other is false.  Since it is true that all humans are mammals by subalternation we know that 1 is true . Thus, we can say that 1 is true because we know that 3 is true and 2 has to be false because it is the contradiction of 3.

3. All humans are mammals

But what are we to make of this on the modern interpretation? Can we no longer say that 1 is true because of the fact that all humans are mammals? It is still the case that 2 is false, as it is still the contradiction of 1. But what about the so-called existential fallacy?

But if we take this discussion out of the realm of categorical propositions and start talking in terms of truth-functional semantics don’t we get the traditional square back? So, 1 is written as 1* with

1* Ex(Hx & Mx)

Whereas 2 and 3 turns into 2* and  3*

2* Ex(Hx & ~Mx)

3* (x)(Hx–>Mx)

So to get the traditional square back we would need to show that 3* implies 1*.

Consider the following proof,

A. (x) (Hx –>Mx) [assumption]

B.  Ex (Hx) [assumption]

C. Hy [Existential Instantiation of B]

D. Hy –> My [Universal Instantiation of A]

E. My (Modus Ponens D, C)

E. Hy & My [conjunction introduction]

F. Ez (Hz & Mz) [existential generalization]

So, if B is correct and there are humans then 3 does entail 1 just like Aristotle said. Am I missing something?

Plant Rights? Yeah Right!

Richard Brown 2 Comments

Over at the Opinionator there is a very nice article examining the issue of whether we should eliminate meat-eating in nature if we could. Personally I think that I agree with McMahan’s conclusion that we have more reason to eliminate meat-eating in nature (if we could without great harm) than we do to preserve the various carnivorous animal species. What is striking are the two themes of the comments, or at least the first page of comments…I did not have the strength of will to go through all 11 pages of them. The first is the ludicrous idea that McMahan is somehow advocating the extinction of the Human Race. He very clearly says that humans should stop eating meat and become voluntarily non-carnivorous. The second theme in the comments is that plants have lives and when we eat them we cause them suffering so even being an herbivore is not good enough. Since this is obviously absurd it is concluded that the original claim was also absurd.

Why is this idea so prevalent among people? Our best scientific theories about the world suggest that you at least need some kind of central nervous system in order to have pain or suffering. Carrots have no central nervous system and so cannot suffer. One reason someone might object to this is allegiance to some kind of radical substance dualism. Non-physical minds can be had by anything, even carrots! But just as there is no reason to think that substance dualism is true for humans there is even less reason to think that it is true of carrots. One other line of evidence often cited is that plants react to their environment in ways we didn’t know about 1000 years ago. We have all heard about plants responding to music, “screaming” when in danger, “warning” other trees about fire, etc but isn’t it quite obvious that this is no more evidence that plants feel pain than finding out that a Roomba emits a certain frequency when it is smashed would be evidence for it feeling pain? Plants are alive and react to the environment but unless they have some kind of brain or brain-like system there is no reason to believe that they feel pain or suffer. Reaction to physical damage does not entail that there is pain much less suffering.

Now, I grant that it is conceivable that plants feel pain, and that the issue of whether it is moral to eat them hinges in large part on the answer to this question; if carrots suffered it would be prima facie wrong to eat them. I think I can also grant that we do not know with absolute certainty that plants don’t feel pain, so we cannot rule out that the actual world is in fact a world where carrots feel pain. Even so, if that were the case then McMahan’s argument would have to be put in terms of turning all species into photosynthesizes, or some other non-predatory way of producing energy and the main conclusion would still stand. So it looks like the appeal to plants is doubly off-base. In the first place it is off-base  because though plant sentience is a possibility there is no serious reason to think that it is actual and secondly it is off-base because the conclusion would still follow if we amended the argument in a suitable way.

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.