Saturday, January 05, 2008

Dialogue with Shygetz on DC

VR: So when we say mental states are brain states, what do we mean?

Shygetz: We mean that each mental state corresponds to one and only one brain state. However, you labor under the misconception that when you think "apple" and I think "apple" we have the same brain state. We do not--when you think "apple" what color fruit are you imagining? What size, what exact shape, shiny or dull, alone or in a context? If "apple" doesn't refer to a single unique physical state, what makes you think it refers to a single unique mental one.

VR: There are, of course, various chairs, some made of different stuff and some different colors, but there is something that makes them all chairs. Doesn't everyone's thought of an apple have to have something physical in common if it is a physical state.

More, A can correspond to B without being identical to B, so there has to be more to identity than correspondence.

Causal role is determined by physical structure. If there is nothing about the property "being a thought about a pencil" that is identical to some particular physical state-type, then the mental state-type cannot be causally relevant.

Shygetz: And the only way you can do this is to posit something that interacts intimately with physical matter and can be strongly affected by physical matter while remaining somehow distinct from physical matter in some manner you have yet to even attempt to explain. I hope you are not trying to imply that dualism is more simple than physicalism, because it is not by some undefined by doubtlessly large amount. You are positing an entire new branch of physics based on a substance that violates its current laws.

VR: No problem. We need this one in order to preserve the logical foundations of science.

Shygetz: Yet again, you make a bald assertion that actually flies in the face of (admittedly incomplete) evidence. Do you have any evidence that this is true? If so, by all means present it. If not, you are not making an argument--you are declaring by fiat. Argument is necessary, sir; I don't think anyone here will be convinced by raw audacity. Show me a reason to think that physical data are insufficient to determine mental states--otherwise, you merely continue to beg the question.

VR: It's very simple really. Identity claims are necessary truths. In order for physical states to determine intentional states uniquely, it must be logically contradictory to deny the mental state once the physical information is given. Postulate any amount of physicalistic information you want, and you will never get anything that logically entails the existence of a mental state. The only way to get an argument that has a conclusion "X is about B" is to have intentional states in the premises. It doesn't matter how much physical information you give, it will always be logically possible for me to deny the existence of the mental state without logical contradiction.

The irreducibility of intentional states to physical states is held by many philosophers, many of whom, like Donald Davidson, are philosophical naturalists. There is also the argument that intentional-state attributions involve normative elements, and therefore, cannot follow necessarily from the existence of physical states. Many naturalists accept a dualism of properties but try to avoid a dualism of substances. The problem then arises as to how those nonphysical properties fit into a physical world, and also how non-physical properties can possibly be causally relevant.

Shygetz: Ah, now you are at least starting down the right path. Have you ever, and I mean EVER, added, subtracted, or manipulated powers in a mental vacuum? No; you always bring along your "unique perspective" which changes your mental state. Computers can add in a vacuum; if I take two identical computers and have one add 2 + 2, then take another computer and manipulate its physical states so they replicate the first one exactly, the second computer will have added 2 + 2. What is the reason to think that the human brain is different when adding 2 + 2?

VR: Computers have no first-person perspective. Therefore, they do not literally add 2 + 2. They do not perceive the relationship amongst the meanings. We perceive those relationships. However, physical facts are not perspectival. If my perspective determines how atoms go in my brain, we have a non-publicly accessible fact that determines physical states. That's not considered good naturalism.

It's like taking a bunch of indicative facts about the world and concluding the existence of an objectively binding moral obligation. You have to wrong type of facts on the one side to draw the proper conclusions on the other.

You have to go from facts are not subjective or perspectival, not normative, not intentional, and not purposive, and yet these facts have to entail truths that are subjective/perspectival, normative, intentional and purposive. That is a good deal more than just a question about how the bacterial flagellum got engineered.



At 1/06/2008 12:13:00 PM , Blogger Blue Devil Knight said...

Identity claims are necessary truths. In order for physical states to determine intentional states uniquely, it must be logically contradictory to deny the mental state once the physical information is given.

"Water is H20." Is it "logically contradictory" to deny it?

At 1/07/2008 05:58:00 AM , Blogger Rino said...


If I remember my Kripke, he offers reasons for saying that identities are necessary. I guess we can ask: if I mix H3SO4 together, could I still get water? It seems improbable to me. But I'm not decided on the issue.

At 1/07/2008 12:38:00 PM , Blogger exapologist said...

He does think they're necessary. But I think BDK's point is that (as Kripke pointed out) some necessities are knowable only a posteriori, in which case it's not contradictory to deny them.

At 1/07/2008 01:00:00 PM , Blogger Rino said...

Hi Exapologist,

You could be right here, I don't remember Kripke well enough. Perhaps I can ask: Are we talking about words or ontology? For example, perhaps it is true that the word 'water' and the word 'H20' are synomyms, and it could be otherwise. However, is it really the case that the substance in the world with liquidlike, colourless, tasteless properties is waiting on humans to know about it, in order to prove that it is identical to the liquidlike, colourless, tasteless substance that it has been for eons? It seems that the two were identical, because there was only one thing, long before any human ever existed to know about it.


At 1/07/2008 06:33:00 PM , Blogger properly basic said...

""Water is H20." Is it "logically contradictory" to deny it?"

Isn't this the same statement as "A is A?" If yes, how is it not "logically contradictory" to deny it?

At 1/07/2008 09:04:00 PM , Blogger exapologist said...

Hi rino and properly basic,

I understand your point, and I certainly agree with you about the metaphysical necessity of the identity relation. But I think (and I may be wrong -- I jumped into the discussion late) BDK is pointing out that even if physical states are identical to intentional states (or if one metaphysically includes the other), one shouldn't expect to see the identity relation reflected in language via the inability to consistently deny identity. For some identities are knowable only a posteriori, as Kripke and Putnam pointed out.

The claim

1. Water is not H20.

Is necessarily false, (since it turns out that water *is* H20, and the identity relation between a thing and itself is metaphsyically necessary); however, it's not *a priori* that it's false, since one had to do some science to discover that 'water' and 'H20' are co-referential natural kind terms. If one had said instead that

2. Water is not water.

Then it would be true to say that it's not only necessarily false, but also a priori.

I may be wrong about what BDK was after in his remarks, though, so I hope I"m not going off on a tangent!



At 1/08/2008 11:38:00 AM , Blogger Blue Devil Knight said...

Thanks exapologist. That was what I was aiming at.

At 1/09/2008 08:21:00 AM , Anonymous Deuce said...

blue devil knight:
"Water is H20." Is it "logically contradictory" to deny it?

Look closely again at Victor's statement:
In order for physical states to determine intentional states uniquely, it must be logically contradictory to deny the mental state once the physical information is given.

The bolded part is key. It's not logically contradictory to say that in some conceivable universe, you could have something like water (from a macro perspective), that didn't have the molecular composition H20. However, once the physical information is given about the actual universe, it is logically contradictory to deny that water is H2O, because it contradicts that physical information.

By contrast, as Victor states, you can "Postulate any amount of physicalistic information you want, and you will never get anything that logically entails the existence of a mental state."

At 1/09/2008 11:24:00 AM , Blogger exapologist said...

Deuce's point is interesting. It sounds very much like the move Joe Levine makes in his paper, "Materialism and Qualia: The Explanatory Gap", as well as Chalmer's Zombie argument, which is based on his version of two-dimensional semantics plus the notion of logical supervenience. However, that argument has come in for some rather heavy weather in the relevant literature. For example, it's been pointed out that even if you had all the facts about the microphysical states of H20, you still might not be able to deduce the existence of water (see, e.g., Ned Block and Robert Stalnaker's "Conceptual Analysis, Dualism and the Explanatory Gap", The Philosophical Review 108, No 1, 1999.

Perhaps, though, there is a good reply to this. If so, I would be very interested in hearing it.

At 1/09/2008 12:32:00 PM , Blogger Blue Devil Knight said...

Yes, this is Chalmers' tack too. But if you look at the rest of Victor's post he is arguing we are already able to know that denying the identity claim isn't contradictory. That is, Victor doesn't need to know any more about the physical correlate of mentation, as there is no way it will catch up.

He said, "It doesn't matter how much physical information you give, [sic] it will always be logically possible for me to deny the existence of the mental state without logical contradiction."

I would argue that we don't have a good specification of either side of such identity claims, so confidently denying them, affirming them, whatever, is speculative, premature, hubristic. As I've argued many times here before in different contexts.

At 1/10/2008 08:54:00 PM , Blogger Victor Reppert said...

But look at how different the cases are between water and H2O on the one hand, and between a physical state and a mental state with a determinate content that is recognized by the person. In the former case we find exactly the same physical structure every time we find something with the other properties of water. And with this reduction, the "phenomenal" properties are treated as the mind's reaction to water rather than intrinsic to water, so once again we get that "siphoning off" effect that we found in other successful conservative reductions.

Are the brains of, say, everyone who is a theist, going to be discovered to have a certain type of characteristic that is not present in the brains of atheists or agnostics. If "belief that God exists" is type-identical to a particular physical state, that is what neuroscience should expect to eventually find. But whenever I bring this up over on Debunking Christianity, the naturalists there seem to want to deny that we need to find such a common pattern in the brain.

If it's just token identity and we aren't worried about type identity, then the problem is that token identity is not sufficient to guarantee that the mental properties are going to have any causal relevance. A baseball can be token-identical to the baseball that Gonzo hit against Mariano Rivera to win the 2001 World Series for the Arizona Diamondbacks, but that does not mean that when that ball is thrown at a window, that characteristic (being the baseball Gonzo hit) is going to have any relevance to whether the window breaks or not. Sturctural properties seem to be the ones that do the work in the physical world.

Given what the physical must be in order to be the physical, and what the mental must be in order to be recognizably mental, it just seems to me that further scientific investigation has about as much likelihood of getting determinate mental content out of the physical as it has of getting determinate, objectively binding moral obligations out of the physical.I admit that it is not self-contradictory to suggest that some future scientific revolution will reveal the relevant reduction.

I would say that at present, our understanding of water is such that we are not prepared to use the word for anything that isn't H20. That's because our physical knowledge has gotten built into the concept. The Bablyonians would probably call XYZ water, we almost certainly would not.

At 1/14/2008 11:11:00 AM , Blogger Blue Devil Knight said...

Can't vouch for it, but paper but you might be interested in arguing against something I've advocated here phenomenology of propositional attitudes. (Well, almost against something I've argued: I've argued that propositions (if they exist) have no phenomenology, not that propositional attitudes don't have a phenomenology).

Propositional attitudes are often classified as non-phenomenal mental states. I argue that there is no good reason for doing so. The unwillingness to view propositional attitudes as being essentially phenomenal stems from a biased notion of phenomenality, from not paying sufficient attention to the idioms in which propositional attitudes are usually reported, from overlooking the considerable degree to which different intentional modes can be said to be phenomenologically continuous, and from not considering the possibility that propositional attitudes may be transparent, just like sensations and emotions are commonly held to be: there may be no appropriate way of describing their phenomenal character apart from describing the properties and objects they represent.


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