lunes, 18 de abril de 2011

Qualia, Sensation and Wittgenstein


The Human Condition (1933)
Rene Magritte
"We see [the world] outside ourselves, yet all we have of it is a representation inside ourselves. In the same way we sometimes locate in the past something that is happening in the present. Time and space then lose that crude sense of which only everyday experience takes account"

The False Prison
A Study of the Development of Wittgenstein's Philosophy
by David Francis Pears

(Go here for an essay dealing with the meaning of the title, "The False Prison".)

Comments on similarities between qualia in Edelman's theory of mind and Wittgenstein's treatment of sensations. (Go here for an essay dealing the relationship between Wittgenstein's type of philosophical therapy and E. O. Wilson's program of consilience.)

I am getting through large parts of "The False Prison" and I have been thinking about Wittgenstein's distinction between
i) the human experience of sensations (qualia, "raw feels") and
ii) human experience of a brain-constructed view of an external world full of coherent objects.

The Double Secret (1927)
Rene Magritte
"An object implies that there are other objects behind it..."

These two types of human conscious experience correspond roughly to the popular division of consciousness into perceptual/abstract, primary/higher-order, Ned Block's P- and A-consciousness. Wittgenstein claimed that there is NO way for us to communicate to each other what our personal qualia feel like. I can never really know for sure if my pain feels like your pain.

For interpersonal communication, the human brain relies heavily on its higher-order mode of consciousness that chunks together the elements of raw sensations into coherent objects. To communicate with each other, we associate our brain-constructed "images" of objects with words. For most of the worldly things we need to communicate with each other about, our linguistic system works just fine. For communicating with each other about our qualia, natural languages fail.

Damasio has written about "Descartes' Error", but there was also Descartes' Diversion, his diversion of science and its objectification of reality away from the problem of mind. People who wisely accepted this diversion away from scientific investigation of mind were saved the agony of trying to prematurely construct a science of mind.

How do I define "premature science of mind"? As a mind/brain monist, I have always done so by calling dualistic theories of mind premature. I have long imagined that the SOURCE of dualistic theories of mind was over-reliance on introspection. Bergson's theory of mind in his book "Matter and Memory" is a good example of a premature theory of mind. I generally credit Edelman with the first and so far (this is increasingly amazing with each passing year) only full-sized theory of physically embodied mind. Edelman went beyond just constructing a biological theory, he examined some of its philosophical implications. From the perspective of modern neuroscience, Edelman's first two assumptions (physics and evolution) are "mainstream" and expected. Edelman's third assumption (qualia) is the most revolutionary from the perspective of modern neuroscience, while being concerned with exactly the aspect of mind that many philosophers fault biologists for being most likely to ignore.

I cannot prevent myself from trying to imagine how Wittgenstein would have deconstructed Edelman's theory of mind. At the core of a Wittgensteinian analysis of Edelman's theory would be a focus on the forms of language which Edelman selected in order to talk about sensations (remember, Wittgenstein's claim that nobody can coherently describe and communicate their sensations in language).

Now, Edelman tried to accept both
1) the existence of qualia ("sensations" in Wittgenstein's terms.....Wittgenstein wanted to use "plain" language, not the dubious constructs such as "qualia" that are only used by funky philosophers and not the average person)
2) that "We cannot construct a phenomenal psychology that can be shared in the same way as a physics can be shared".
"So far Edelman is making all the right moves," I imagine Wittgenstein thinking. But how do we incorporate sensations into a scientific theory of mind in a way different from what would be forced on us by the tools available to the physicist? Edleman's answer: we must make an attempt to correlate human subjective experiences to what our objectively scientific model of mind PREDICTS about human sensations. Now, I have to admit that Edelman never put the situation in such blatant terms ("theoretical predictions about the experience of qualia"); he walked right up to the brink of doing so then walked away. I suspect there is an opening here for Wittgenstein to jump in, but I cannot quite see how it would go down. In any case, Edelman tried to prevent himself from dealing with the can of worms that this opens up. Edelman tried to limit his theory to an attempt to map out some boundaries, the "constraints on experience." Does Edelman really save his theory by making this move or is he just sweeping the dirty aspect of qualia under the rug? I imagine Wittgenstein moving to the edge of his seat and preparing to jump into the fray at this point, the point at which Wittgenstein would have suspected that Edelman was on the verge of building metaphysical castles in the sky. What can Edelman possibly say about sensation without becoming incoherent?

Having said all of the above I briefly return to:
Bergson's failed theory at the end of the 1800's and his view of "pure thought" defined as "the mind reflecting on its own conditions of thought". Something about this definition appeals to me, so I will run with it into the 20th century towards Wittgenstein and Edelman.
What are the "conditions of thought"? Edelman's Qualia Assumption unavoidably positions qualia as a "condition of thought", so if we apply Edelman's line of theory development to Bergson's starting position, we see (as I believe Wittgenstein would have seen) that "pure thought" must deal (at least in part) with qualia. Wittgenstein would have asked, "So how can your theory of mind explain thought, in particular how do you explain sensations, in the language of science?" And Wittgenstein would have answered himself, "Bergson could not do so, so in the end Bergson created a dualistic, metaphysical, and failed theory of mind." From Wittgenstein's position, did Edelman do any better?

Can Edelman's Neural Darwinism of "working up successive layers/loops of selected memory patterns" and "recursively synthesizing increasingly complicated tangles of reentrant mappings" bring us to some theoretical model of an "emergent level of thought" that CAN satisfy Wittgenstein and silence his objections? Or would Wittgenstein also condemn Edelman's theory as a metaphysical castle floating in the sky?

As described by Pears, Wittgenstein's analysis of the problem that sensations pose for philosophy of mind carefully progresses through several levels. First, Wittgenstein dealt with what to many people is an issue so obvious as to need no consideration. However, Wittgenstein knew the importance of exploring the mental tautologies that we usually take for granted. Thus, the first issue for Wittgenstein in dealing with sensations was the issue of possession. "How do we know who owns particular sensations?" Wittgenstein concludes that our brains are constructed so that they automatically assign sensations to the correct owner. In other words, if you have a human brain, then you need not worry about assigning sensations to the correct source, your brain will do this task automatically. This is also Edelman's first move (page 135 of Bright Air, Brilliant Fire): "only through direct possession by an individual of the appropriate morphology and experience do qualia arise." Edelman states the logical implication of this for theories of mind: a "theory [that] would, through the communication of its structure, allow an imaginary qualia-free animal [to {I really wonder if Edelman had an editor for his books}] know what qualia are-is not feasible." Wittgenstein hates theories, but here Edelman's program to explain how mind is embodied has led him to included Wittgenstein's first main conclusion about sensations in his theory of mind.

In Wittgenstein's analysis of sensation, the second issue is discrimination between sensations. This is also Edelman's next move. Edelman points out a fact "that has been known for a long time": that qualia can be automatically distinguished within our subjective experience because of the unique structure of each distinct neural network within which our various sensations are constructed. Edelman as arrived at a biological tautology as austere as Darwin's mechanism for evolutionary change by Natural Selection, so austere than many current Philosophers of Mind refuse to accept it, just as many philosophers have been reluctant to accept that Natural Selection is an adequate (powerful enough) mechanism to account for the diversity of life. However, Wittgenstein is not your average philosopher. Edelman's position with respect to discrimination between qualia is exactly that arrived at within Wittgenstein's philosophical analysis of sensation!

Having dealt with (at this point many would protest, as Edelman himself admits, that it seems we are being too generous to just describe what Edelman has done with respect to qualia as "dealing with", his critics would argue that this should be qualified to reflect the fact that from the perspective of many philosophers Edelman has only minimally dealt with qualia; he is clearly impatient with having to waste any precious time on the subject) our sense of ownership of qualia and our ability to discriminate between qualia, Edelman resists the temptation to take any further steps towards additional analysis of subjective experience. So, would Edelman's handling of sensations (qualia) have satisfied Wittgenstein? Has Edelman satisfied Wittgenstein's basic dictum, that having said all that can be said one should remain silent about everything else? By formulating a theory of embodied mind has Edelman for the first time succeeded in constructing a theory of mind transcending metaphysics, and is this accomplishment identical to the conditions required to silence the great critical philosopher, Wittgenstein? As of now, I must answer "yes", but I wish Wittgenstein were still with us. I worry that he would have had an even deeper insight and been able to pull the rug out from under Edelman.

Now, if the above analysis is correct, then in essence Edelman found the same place for qualia in his theory of mind as Wittgenstein had earlier found for sensation in his philosophy of mind, a common, solidly rooted place that does not float any metaphysical castles. If this is the case, then I have to ask: did Edelman and Wittgenstein reach this common destination independently? With respect to the Mobius strip analogy, we can imagine that they might have reached the same destination by independent traversal of the same path, but could they possibly have reached their common conclusions by two independent paths leading in opposite directions around the Mobius strip?

I suspect that they must have followed different paths, even though it is clear that Edelman has some knowledge of Wittgenstein's philosophy. Wittgenstein tried to totally abandoned theories and the objective methods of science. Edelman claims to have constructed his theory as a solid scientific theory that just happens to have some interesting philosophical implications because of the subject matter. Edelman insists that his is the only possible scientific way to incorporate qualia into a theory of mind. Wittgenstein's arguments about the nature of sensations are constructed entirely from the inner perspective and he claims that his is the only possible way to incorporate sensations into a logically consistent phenomenology. Should we view the ability of Wittgenstein and Edelman to reach the same conclusions by two different means as a satisfying way of "double checking" their result or is this just an artificial type of wave/particle duality that says more about our mistaken and fractured way of looking at the world than it does about some deeper meaning in the fact that Wittgenstein and Edelman reached the same final conclusions?

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