Archive for the ‘Philosophy of Mind’ Category

A Lewisian Argument for Conceptualism

July 10, 2008

Below is a revision of a paper I wrote for a class on David Lewis’ On the Plurality of Worlds in which I argue for conceptualism about abstract objects. I tried to make it understandable for general readers, but I apologize for readers who are interested but not very well-versed in philosophical style writings. Hopefully this piece will be self-explanatory enough. Originally the instructions for the paper were to try to mimic Lewis’ style, summarizing some argument or idea he has, criticizing it, and then offering a possible defense. The defense of Lewis that I wrote at the end doesn’t seem very substantial to me, so I will attempt to refute it and thus vindicate my argument for conceptualism. Before actually making the argument, I will give a brief introduction to modal logic for those who are new to the subject. (more…)

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The Argument from Rationality for Absolute Personal Identity

March 1, 2008

I have seen this argument used before elsewhere, but I thought I would post it here when I was reminded of it while reading Andrea Christofidou’s paper “God, Physicalism, and the Totality of Facts” (Philosophy, vol. 82, October 2007, pp 515-542). I think its fairly well-known, but I want to expose people who haven’t heard of it before. It attempts to show that a view of personal identity as an absolute and irreducible non-physical quality that defines us (as opposed to something like memory grounding personal identity) is a precondition for us to be rational.

The Argument from Rationality:

1. In order for me to be rational in forming my beliefs, I must be able to consider all the premises of an argument and its conclusion.

2. In order to be able to consider all of the premises of an argument and its conclusion, I must exist from the moment I consider the first premise to the moment I assent to or reject the conclusion.

3. If I exist from the moment I consider the first premise to the moment I assent to or reject the conclusion, then I am absolutely the same particular individual across a stretch of time.

C. Therefore, in order for me to be rational in forming my beliefs, I must be absolutely the same particular individual across a stretch of time.

Insofar as the defender of memory views of personal identity and other views aren’t willing to give up their claim to rationality (lest we dismiss them and ignore them) it seems they must agree that we are absolutely the same particular individual across a stretch of time. I think the absolutist view of personal identity causes problems for physicalism as I have argued elsewhere. I wonder how a defender of a non-absolute view of personal identity would defend against this?

Dualism and Joint Causality

December 21, 2007

In his response to my argument against property dualism from its inadequate account of personal identity, Brett made a suggestion that if the soul together with the body is adequate to generate a continuity of consciousness, that the body alone is adequate to generate a continuity of consciousness. Here I will examine and critique these suggestions.

Brett wrote:

“I have no problem accepting a materialist account of the mind and here is why: if the dualist hold that certain material states of the brain “capture” or “hold in” the soul to the body, then they believe that it is sensible to say that some physical state causes the continuity of the soul’s interaction with the body. It appears to me that a dualist would have to accept this in light of what we know about labodomis: if dualism is true, then the altering, or rather severing, of the frontal lobe causes the aspect of the “soul” that causes emotion to vanish and go off somewhere else. Therefore, from this, we can draw a general principal (lets just assume that other phenomena of the mind like belief work in the same way emotion has been demonstrated to work) that physical states are a necessary factor for states of consciousness to endure continually. Well, if ((X and S)->continuous Y) where X is a certain chemical combination, S is some soulish agent, and Y is the consciousness being presently experienced, then it necessarily follows that (X->continuous Y) is also possible, where X and Y are the same things. If one is to say that X, since it is material and its parts are being replaced, cannot be one of the casual factors in bringing about uninterrupted consciousness because its token is changing constantly (X->continuous Y), then it follows that X should also be insufficient to continually “cage in”, or “hold onto” the soul in an uninterrupted fashion, as would occur in the case of ((X and S)->continuous Y). In short, it seems that the argument that Michael uses to critique the brand of materialism under question is either valid, and therefore the dualist and the monist account of consciousness are both incompetent, or the critique is invalid, and the dualist and monist models are both workable. I believe that both models, the dualist one and monist alike, are possible and that the critique does not show that either are incompetent, but I think the monist account wins because it does not multiply as many bodies to explain the phenomena as with the dualist account, when taking occum’s razor into consideration.”

I will try to analyze this part of Brett’s post in 3 segments.

(1) Brett first states that “if the dualist hold that certain material states of the brain “capture” or “hold in” the soul to the body, then they believe that it is sensible to say that some physical state causes the continuity of the soul’s interaction with the body. It appears to me that a dualist would have to accept this in light of what we know about labodomis: if dualism is true, then the altering, or rather severing, of the frontal lobe causes the aspect of the “soul” that causes emotion to vanish and go off somewhere else. Therefore, from this, we can draw a general principal (lets just assume that other phenomena of the mind like belief work in the same way emotion has been demonstrated to work) that physical states are a necessary factor for states of consciousness to endure continually.”

Brett uses language of “capturing” which seems to imply that on his view of dualism, the dualist is saying that the body is what causes the continual interaction between soul and body. But this is false. Dualists would hold that a precondition for the interaction of the soul with the body is the existence of specific physical states (the body, and more specifically, certain causal channels within the body). But preconditions (Brett’s “necessary factors”) aren’t causes. The example of lobotomy does show that the soul may have some powers that are inactive if certain physical states aren’t in place that the soul will normally act through. But that doesn’t imply that the body and specific brain states are efficient causes of the soul continually interacting with it–no more than the existence of a plaster surface is the efficient cause of a three week painting project.

It is the assumption that physical states cause the continual interaction that leads to Brett later arguing that “if the body can cause continual interaction, then the body can adequately cause continual consciousness”. I will continue to address the soul/brain relation below as related issues come up (see [3]).

(2) Next Brett says “Well, if ((X and S)->continuous Y) where X is a certain chemical combination, S is some soulish agent, and Y is the consciousness being presently experienced, then it necessarily follows that (X->continuous Y) is also possible, where X and Y are the same things.”

It seems to me that this is false–even obviously so. Take for instance the good ole’ volcano experiment that you did in fourth grade. You wanted to make foamy, fizzy bubbles. So you took vinegar (ingredient x) and baking soda (ingredient s) and you put them in the cheap paper-mache volcano sculpture. You got a whole ton of bubbles (continuous Y) and were a very happy kid.

But was it ever reasonable to believe that ingredient x was adequate on its own to give a continuous Y? I don’t see how. It is not in fact sufficient. The fact that X and S can lead to Y doesn’t imply by any known rules of inference that I’m aware of that X is sufficient by itself to generate continuous Y.

But, you might protest, we *know* this to be the case with baking soda and vinegar because we’ve *seen* the interaction between them and that both are joint causes of bubbling. But that isn’t true with the soul and brain states. We haven’t seen that they’re *both* jointly necessary. We just know that the brain states are necessary–the question of whether they are jointly necessary is something else. So its simpler, given this consideration, to assume that the soul is not a necessary factor and need not be postulated to explain consciousness.

I would agree with this (other things being equal–like assuming we don’t have any other arguments for the existence of a soul). But that last comment (“we know this to be the case with baking soda and vinegar… but that isn’t true with the soul and brain states…”) is the *real* intuition–a principle of parsimony–that motivates the assumption that a soul isn’t necessary to explain consciousness. All by itself, the assumption in the last comment (“we know…but this isn’t true…”) serves to undercut the assumption that a soul is necessary. But this is very different from the line of reasoning expressed in the argument for “possibly, X–>Y”. That original reasoning was what I have already criticized above; I thought it was more closely analogous to assuming that because baking soda and vinegar are jointly necessary and sufficient for bubbles, that vinegar by itself is necessary and sufficient for bubbles. Why incorporate that whole extra first part that is, by itself, fallacious reasoning until you add in the principle of parsimony to explain what you’re really trying to say (“we shouldn’t assume both are necessary for consciousness if we only experience one”) if the principle of parsimony would have got the job done in the first place?

(3) Next, Brett suggests that “If one is to say that X, since it is material and its parts are being replaced, cannot be one of the casual factors in bringing about uninterrupted consciousness because its token is changing constantly (X->continuous Y), then it follows that X should also be insufficient to continually “cage in”, or “hold onto” the soul in an uninterrupted fashion, as would occur in the case of ((X and S)->continuous Y).”

I think this assumes that on my account, a single continuous physical state is causally responsible for the
continual interaction between soul and body (I already discussed this above somewhat). But I deny this; I think that the soul by its nature interacts with its body so long as the body is available. The soul’s qualities are what cause the continual interaction with the brain, through the various causal channels in the brain.

You might think of it in terms of a computer–more specifically, a robot–like this: certain faculties of the soul are like USB ports. They can sense whether a USB drive (the body–specifically the brain) has entered into it (whether the soul and body are united). When the USB drive does enter into the port, it accesses it, (the soul is aware of the body) and displays it as available on the computer screen (kind of like the brain displaying sensory data [transmitted through the eyes] to the soul). Then the computer (soul) can interact with the USB drive (body/brain), transferring files on and off of it (causing brain events, and allowing physical/brain events to be preconditions to the soul causing mental events–if they are identified as the appropriate kind of physical events). But it is the computer’s robotic arm that goes through the process of inserting the USB drive (it is the soul that causes itself to be united to the body and keeps that union in place).

So some powers of the soul cause it to automatically be joined to the body if the right physical preconditions are in place.

Now, even if we grant the assumption that the body causes the soul to remain united to it, what follows? I’m not sure we can automatically go to Brett’s conclusion–that it follows that the body could be an adequate grounding for the continual existence of certain mental entities. Why would we have to assume that in order for the soul to remain united to the body, there must be the *same* body parts that cause it to be continually united? I don’t see why the physical states that causes soul-body union couldn’t be replaced over time slowly so that eventually they are totally replaced. It could be that every physical state of the type U (cause of the union between soul and body), whether it be U1, U2, or U3… Un, U[n+1], will automatically cause the union of what remains of the body with the soul that was united to it before. So why not think the soul remains united to the body so long as there is a state of type U?

For an analogy, think of a king’s throne that a servant has to carry on his shoulders to keep the king up. In order to keep the king supported, all you need is an entity of type S–a “strong servant type” of human being. There doesn’t have to be absolute numerical sameness throughout time–you can replace one servant with another after the first guy gets tired. All that has to be there is *someone* who can handle the load. Because we aren’t talking about an identity relation here (the servant example is illustrating continual causality, not sameness or identity) its okay for him to be replaced. He can uphold the king, who remains elevated in place the entire time.

So I think the problems with Brett’s arguments are numerous. Some of them seem to be fallacious (until coupled with considerations that would have illustrated the same point just fine on their own); others seem to be working off of assumptions that dualists aren’t willing to grant; while still others seem to be easily answerable.

Physicalism, Property Dualism, and Personal Identity (II)

December 21, 2007

Brett has suggested that my critique of property dualism as adequately grounding personal identity fails. Here I will attempt to respond to his criticisms of my argument.

Brett wrote:

Michael introduces this as a critique of type-property dualism, but this seems to be another critique of token-property dualism taken from a different angle. Michael points out that the second tape is a “different tape” from the first one, which seems analogous to the difference between the first token-molecules of the mind being different in token to the second token-molecules of the mind, even though they are the same type throughout. But as Michael himself points out the same image will pop up on the screen, and so he agrees that it is the same “type” and that nothing has changed as far as “type” even though, with the switching of tapes, things have changed with “token.” And since the “type” does show continuity between the exchanging of tapes, this hypothetical situation does correlate to what we experience phenomenological. So, in the instance of property dualism, where aspects of consciousness are the emergent property of brain chemicals, it seems that the changing of brain chemicals will not interfere with the belief, feeling, or image that it emergently creates.

Brett says that I am giving a critique here of token-property dualism. But what I am really arguing is that type-property dualism is counterintuitive. Its correct that I am pointing out that the second tape of the same type is a different token from the first one, analogous to the difference between physical state X token A and token B. And yes, the same type of image will appear on screen. So there is continuity of the type of image even though there’s two different tokens.

But that’s the whole problem. Personal identity, whatever it is, has to involve total continuity and sameness across time. Now think of how property dualism articulates personal identity. If a ship lost its mast and got a new mast, we wouldn’t say that it was exactly the same ship. Whatever we believe about personal identity, we can’t believe that its grounded in switching the ship’s mast every time it falls off; that’s precisely *not* a continuity of identity, but two totally different things. Similarly, two different showings of the same film are *not* the same film. They are two very different things.

Now, the continuity of mental states Brett is imagining that gives us personal identity is like the continuity between two different showings of the same film on a tv screen. Its two very different things, not having any of the exact same parts or properties in common with previous states of the mind. Two different video tapes have successively gone into the VCR, and now the image being projected on the screen is a different one from before. This is not a continuity but precisely a discontinuity of identity between this showing of the film and the previous one. It may be displaying the same image, but we would not say its the *exact same film*.

Its like the replacement mast on the ship: sure, its a mast–but its not the same one as before. And similarly this is not a continuity but precisely a discontinuity of identity between this mental state and the previous one. Thus the continuity that is suggested by this theory of personal identity is like the replacement of one mast on a boat with another mast–hardly adequate for claiming numerical sameness throughout time in the sense necessary for *identity*. At most, this theory of personal identity seems like it can be dubbed a theory of *personal similarity*.

In Brett’s next section he talks about how substance dualism is unparsimonious. This may be true if we have no arguments for it. But of course an argument for dualism from the inadequacy of non-dualist theories of personal identity would qualify to override this appeal to parsimony. For if materialists can’t explain personal identity, and property dualists can’t explain personal identity, then parsimony should be set aside for the explanatory power of substance dualism.

Physicalism, Property Dualism, and Personal Identity

November 1, 2007

I have been thinking about physicalist/property dualist accounts of personal identity, including the memory account especially. The memory account says that personal identity is grounded in the continuity of memory in a single subject throughout time. So long as your current brain has the same memories as time progresses, it can be considered numerically the same person that existed previously as you in the past.

Here I will attempt to offer a critique of this theory of personal identity. As far as I know, this material is all original, but if I have mistakenly started regurgitating something Swinburne said (maybe something I read once and forgot where it came from–you know how that goes), please correct me and give me a chance to apologize.

One thing that strikes me as initially implausible about this account is that the brain has a cycle where it replaces every cell inside itself with new ones. Now, because of this, we obviously can’t locate personal identity in the continuity of a material object’s existence. But I think this fact about the brain also challenges the memory account of personal identity. Lets take what I consider to be the most sophisticated account of something-remotely-physicalist: epiphenomenalist property dualism. Property dualism says there is no immaterial substantial center of consciousness (soul) seperate from the body. Nevertheless, there are mental properties that are not physical properties. Your thoughts are not entirely reducible to physical objects; they have non-physical properties that genuinely transcend matter. Epiphenomenalism identifies mental entities as emergent properties or states that come into existence when the brain is in a certain state.

Now on epiphenomenalism, as I understand it, there is a necessary correlation between physical states and mental properties. A mental property will exist only when a certain combination of physical objects exists in a certain location. What this means is that there is no incorruptible mental life that is beyond the possibility of destruction. Rather, there is the possibility that a person’s consciousness will become destroyed if the physical objects that give rise to it get displaced or destroyed.

Now think about that with relation to certain beliefs which would constitute memory. Your belief that “I was born in a hospital” is a token of a certain belief-type. What that means is that there are more than one beliefs that “I was born in a hospital”. The belief-type “I was born in a hospital” is like the image on a strip of film that has been replicated; it can look exactly the same as other images on other strips of film. For instance if a movie was being mass-produced on vhs for home theater, there would be many versions of the movie, each with their own pieces of film, all looking more-or-less exactly the same.

This would be comparable to your belief “I was born in a hospital”; billions of other people have had this same kind of belief before. There have been many different belief-tokens of this belief-type. So what makes these belief-tokens different on the epiphenomenalist account? They were all produced from different physical locations by different brains. The same kinds of particles that gave rise to a belief-token x1 of type X gave rise to another belief x2 in a different brain. Yet these two tokens x1 and x2 are different precisely because they arose from a different arrangement of material objects. Here’s the thing: if the matter in your brain is being replaced frequently, then it seems that different combinations of matter are producing your beliefs over the years. At one point in your life, combo-token z1 of type Z was producing belief-token x1 of type X. Later, combo-token z2 was producing belief-token x2 of type X. All the matter that gave rise to your first belief has been replaced now. And because different combinations of matter are producing your belief you now hold, we can legitimately say you have a different belief-token.

This seems to undercut the possibility of a continuity of personal identity given epiphenomenalism or pretty much any physicalist or property-dualist account of personal identity. After all, your beliefs *are not the same as they were before*. What was once your belief that “I was born in a hospital” is now a different version–a new token of the same type of belief. If this is true, then we don’t seem to be dealing with the same beliefs that constitute memory; hence it is hard to see how we could be dealing with the same person enduring throughout time if we base personal identity off of memory.

What about just saying that its the type, not the token, that matters in order to retain identical memories? After all, if you still believe “I was born in a hospital”, what does it matter? Here we run into some problems. For think of the analogy with tv again. Lets say there’s a VCR that is your brain, the tape is a brain state, and the images on the tv are the mental states that arise from having the brain state in your brain. If I take a tape of Boodock Saints and put it in, and the tv has a picture of a scene from Boondock Saints, then this parallels what happens when you have a mental state of a certain kind for the very first time emerge from your brain. But lets say that one copy of Boondock Saints gets trashed; this would be comparable to your brain state losing the original physical particles that caused your belief. You would not have the image on the tv that came from the tape anymore; similarly you would not have the belief that came from the brain state anymore. Now lets say we replace the old Boondock Saints tape with a new one of the same kind–a second copy of Boondock Saints–and stick it in the VCR. What would this be the equivalent of for personal identity? It is the same as the lost group of particles being replaced by particles of the same kind in the same kind of relations, so that they give rise to the same type of belief.

But something is fishy here. When we replaced the tape, we don’t have two identical tapes, one that was replaced which is exactly the same as the one that is the replacement. There is not a strict continuity of identity here. When the image of Il Duce with guns blazing pops up on the screen, therefore, it may look exactly the same as the first image that was playing from the original tape; but it is *not* the same. Its a different tape. Likewise, when we replace the brain state with a new brain state of the same kind, it looks like we’re dealing with the same belief; but we’re not. There’s no strict continuity of identity there. If we aren’t willing to say that there is an absolute continuity of identity for the image of Il Duce when we put in a copy of the same tape, then we can’t say we’ve got an absolute continuity of personal identity in memories of the same kind arising from different sets of the same matter.

An alternate way of looking at personal identity is to see it as a basic and unanalyzable notion that is grounded in the uniqueness and distinctness of a person from his or her body. This I find to be the preferable route. Because our intuitions about the absolute continuity of our personal identity throughout time should not be taken lightly, perhaps we ought to accept the mystery and uniqueness of persons without reducing them to a kind or an effect of physical existence.