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Non-deducibility and Informativeness

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Non-deducibility and Informativeness

TecnoTut
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0 of 1 people found this post helpful Posted 05/20/09 - 12:14 AM: Subject: Non-deducibility and Informativeness	#1
Dr. Chalmers, Where do you think the strength of the Knowledge Argument lies within? The claim that Mary cannot deduce phenomenal knowledge from physical/functional knowledge? Or rather, the claim that the phenomenal knowledge is novel and informative? Or both non-deducibility and informativeness? I think it's fair to say any truth that's not logically deducible is informative, and some logically deducibile truths are trivial and uninformative. However, there are some logically deducible truths that are also informative (e.g. calculating a very long and complex mathematical formula). As you know, some philosophers (type-A materialists, such as Dennett and the Churchlands) claim that pre-release Mary can deduce phenomenal knowledge from knowledge of functional facts. But even if we assume that type-A materialism is right, that leaves open the question of whether that knowledge is still informative. Arguably, Mary might still be surprised when she deduces phenomenal truths from functional ones, and thus, reductive functionalism would still remain false. However, I'm leaning towards the claim that non-deducibility is what gives strength to the Knowledge Argument. Following Ayers, I think informativeness is too closely related to our cognitive limitations, and since Mary is allegedly omniscient towards physical-functional facts, I doubt she would be surprised (assuming she can deduce phenomenal truths). Edited by TecnoTut on 05/22/09 - 12:56 AM
I won't utter falsehoods, but I've no objection to uttering meaningless statements - A.J. Ayer, when saying grace. The apparent negation of a pseudo [meaningless] statement must also be a pseudo-statement - from Carnap's Empiricism, Semantics, and Ontology Those who deny [Aristotle's] first principle should be flogged or burned until they admit that it is not the same thing to be burned and not burned, or whipped and not whipped. - Ibn Sina (Avicenna)

davidchalmers
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1 of 1 people found this post helpful Posted 05/21/09 - 09:01 PM:	#2
I'd say nondeduciblity is closer to the crux than informativeness. As you say, there are cases of in-principle deducibility that are nevertheless informative. If the relationship between physical and phenomenal facts were like that, that would be quite compatible with materialism (it would then just be analogous to the relationship between physical facts and complex mathematical facts). Although to be more general, the relevant sort of deducibility isn't just logical deducibility, but something like a priori deducibility. I take the key premise of the argument to be the claim that certain conditionals such as 'If P, then Q' (where P is the complete microphysical truth, Q is a phenomenal truth) are not knowable a priori, even in principle -- i.e. that Q isn't in-principle a priori deducible from P.

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Posted 05/22/09 - 01:23 AM:	#3
Hi Dave, You mentioned that the relevant sort of deducibility in general is not just a logical inference, but should be an a priori one too. Yet, I've always been under the impression that any logical deductive inferences is always a priori in nature. Are you suggesting some logical inferences are not a priori? Or are you saying not all a priori inferences are logical? Edited by TecnoTut on 05/25/09 - 11:11 AM
I won't utter falsehoods, but I've no objection to uttering meaningless statements - A.J. Ayer, when saying grace. The apparent negation of a pseudo [meaningless] statement must also be a pseudo-statement - from Carnap's Empiricism, Semantics, and Ontology Those who deny [Aristotle's] first principle should be flogged or burned until they admit that it is not the same thing to be burned and not burned, or whipped and not whipped. - Ibn Sina (Avicenna)

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Posted 05/24/09 - 05:01 PM:	#4
Hi -- I meant that some a priori inferences are not logical. For example, 'All bachelors are unmarried' and 'There are an infinite numner of primes' are arguably knowable a priori without being logical truths.

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Posted 05/30/09 - 05:05 AM:	#5
I think there may be an issue concerning the notion of knowledge here. It seems to me, at least that it is arguable, that if Mary has all of the physical facts then she could know truths about the world based on those facts (and having never had a phenomenal experience beyond her black and white room). For example, even though she has never seen red before, she could know that a particular apple would be experienced as red based on the physical facts. Mary may not have 'phenomenal knowledge' (whatever that might be) but it seems that she surely could have propositional knowledge.

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Posted 05/30/09 - 08:50 AM:	#6
If I may be direct, I've never found the Knowledge Argument to have even an ounce of plausibility. If I am a physicalist, then my position is as follows: if Mary knows all the physical facts, she knows all the facts there are to know. If there is even one fact she does not know, she does not know all the physical facts. Because the argument assumes both that she knows all the physical facts and that she does not know all the facts simpliciter, it simply begs the question against the physicalist. My own position would be an instance of what Van Gulick refers to as the "zero stop" on the "Mary Train." That is, I do not think it possible for Mary to know all the physical facts given the problem's setup. Alternatively, we can take the premise that Mary knows all the physical facts seriously and get responses like those of Churchland, Dennett, or Hardin. I might even be willing to argue that all responses to the Knowledge Argument must fall into one of these two categories. After all, anyone who gets off the Mary Train after the first stop must have looped around back to my position that she did not, in fact, know all the physical facts. And given the stipulation in the argument that she does know all the physical facts, what would be able to justify such a position other than the assertion that her isolation precludes the very possibility of such knowledge?
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Posted 05/31/09 - 01:11 AM:	#7
Isn't this just a case of equivocation on knowledge? What Mary knows inside the room is robust, certain, formal, deductive, testimonial knowledge which yields ONLY more formalities. What she learns outside the room is weaker, contingent, sensical, experiential, inductive knowledge. The physicalist would just deny the second sort of unscientific knowledge.
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Posted 05/31/09 - 04:45 AM:	#8
Thinking of the experience of colour, eg red, what it is physically? Can't we say that experiencing red creates a neural correlate of red - some form or pattern which we will thereafter know and remember as red.? If Mary knows exactly the physical form of the neural correlate, is she able to experience it? IMO, no. To know - let alone understand - something, we, as a self-organized system, must be able to produce (recreate, remember) the thing in our mind. (In this case we can as well speak of brains, if someone feels it more acceptable.) But we cannot produce a physical form which is necessary for a physical experience from its description only. If it was possible, we could as well grow us wings if we'd like to fly. Philosophically I see the matter boiling down to the metaphysical relation between the state of affairs and its description. We must have experience of both levels to understand the relation. Referring to Tarski, we must understand both the sentence "snow is white" and the state of affairs 'snow is white', to justify whether the sentence is true.
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Posted 06/01/09 - 11:39 AM:	#9
I would describe the thought experiment or argument as demonstrating that Mary only had "objective" knowledge about red, she lacked any "subjective" knowledge about red, and I would also offer that it demonstrates that some of the most important things to "know" are what is experienced and may necessarily fall outside formalized explanation. As far as that applies to consciousness, my guess is that it implies that whatever the physical facts or theories of consciousness are, the experience of consciousness (which really is the heart of the matter) is not going to be able to be contained in the physical scientific explanation as we currently have it. I take it that this crucial lack is why Professor Chalmers has advocated a sort of dualism, since the gap is obviously present, yet missing.
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Posted 06/02/09 - 05:58 AM:	#10
Some of you are missing the point of this thread. Since the difference between Type-A materialists and KA advocates is a matter of a clash of intuitions, this thread assumes the Knowledge Argument is correct (just as Type-A materialists assume it's incorrect), and asks "If the KA argument is valid and sound, then what is it that makes it valid and sound?" Some describe Mary as being surprised when discovering the subjective appearance of colors, and this new information is what gives the KA its strength. My position is that the surprise is irrelevant. What's gives the KA its strength is pre-release Mary's alleged inability to deduce the subjective appearance of red from her knowledge of functional facts. Here's the important part: some may argue that even if Mary could deduce phenomenal facts from functional ones, she can still be surprised after the deduction (just as some logical deductions can surprise us). I think this response against Type-A materialism (Dennett, Churchlands, Tye) fails mainly because Mary is distinct from us in a very important way: she's omniscient regarding functional facts. Although some logical deductions do sometimes surprise us, they won't surprise Mary because, again, of her omniscience. The reason why we are surprised is because of our cognitive limitations, whereas that does not apply to Mary since she's not cognitively limited. This is similar to A.J. Ayer's statement that an omniscient being would not be surprised by any a priori knowledge or long logical deductions. Edited by TecnoTut on 06/02/09 - 07:45 AM
I won't utter falsehoods, but I've no objection to uttering meaningless statements - A.J. Ayer, when saying grace. The apparent negation of a pseudo [meaningless] statement must also be a pseudo-statement - from Carnap's Empiricism, Semantics, and Ontology Those who deny [Aristotle's] first principle should be flogged or burned until they admit that it is not the same thing to be burned and not burned, or whipped and not whipped. - Ibn Sina (Avicenna)

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