Thursday, April 02, 2009

Neuroscience & Philosophy

Linda and I are taking a much-needed day off together today. We're in Ann Arbor, and began with a lunch at one of our new favorite restaurants, Jerusalem Garden. We love eating this kind of food! I began with a bowl of lentil soup w. fresh lemon squeezed in it. Delicious! Linda, who is a grape-leaves-addict, thinks their vegetarian grape leaves are some of the best she's ever had.

Then we walked downtown Ann Arbor - I got a cup of Espresso Royale coffee. When we lived in East Lansing I drank a lot of this stuff and acquired a taste for it. It's a unique flavor that I like a lot. We walked on U-M's main campus "quad" area by the main library - professors were holding classes outside, students were all over the place sunning and talking and being glad for the spring weather.

After a lot of walking we came to Ann Arbor's downtown Borders. The original Borders store was in Ann Arbor. I came down to that great store many times before they grew into lots of stores.

So I'm sitting here in A-A's Borders now drinking Starbuck's and reading Neuroscience & Philosophy: Brain, Mind, Language. The authors are neuroscientist Maxwell Bennett and philosophers Peter Hacker, Daniel Dennett, and John Searle. These are four very big names in the current neuroscience discussion. In this book it's a tag-team match: Bennett & Hacker VS Dennett & Searle. B&H think a lot of current cognitive neuroscience is wacked out. D&S think that philosophical psychology is being "superannuated" by scientific breakthroughs in the study of "mind." Should psychological attributes be ascribed to the "mind" or the the physical "brain?" Is the "mind" "a peculiar, perhaps immaterial, substance distinct from the brain," or is the brain identical with the mind?

Consider this physicalist-reductionist quote from Francis Crick:

"What you see is not what is really there; it is what your brain believes is there... Your brain makes the best interpretation it can according to it previous experience and the limited and ambiguous information provided by your eyes... The brain combines the information provided by the many distinct features of the visual scene (aspects of shape, colour, movement, etc.) and settles on the most plausible interpretation of all these various clues taken together... What the brain has to build up is a many-levelled interpretation of the visual scene... [Filling-in] allows the brain to guess a complete picture from only partial information - a very useful ability." (16)

Bennett and Hacker say, from this kind of reasoning that Dennett and Searle mostly agree with mutatis mutandis, that "brains decide, or at least "decide," and initiate voluntary action."

Bennett and Hacker question the intelligibility of ascribing psychological attributes to the brain. Using Wittgensteinian-type reasoning they believe that those who think it is the physical brain that "decides," "estimates," "interprets data," and so on, are commtting the "mereological fallacy." "Mereology is the logic of part/whole relations." (22) The mereological fallacy is to ascribe attributes of the whole to the parts. This is the equivalent of the informal logical "fallacy of division," which states that it is an error to assume that what is true of the whole is also true of the parts. Quoting from Wittgenstein's Philosophical Investigations: "Only of a human being and what resembles (behaves like) a human being can one say: it sees, is blind; hears, is deaf; is conscious or unconscious." B&H state: "This epitimizes the conclusions we shall reach in our investigation." (19) Bennett is the only actual neuroscientist among the four, and in a technical essay concludes that "claims that synaptic networks, whether of the biological kind or after useful reduction to an engineering device, possess psychological atributes struck me as extraordinary." (66)

Dennett and Searle rebut B&H. Dennett, at times, is really funny. He writes: "When Hacker lambastes me, over and over, for failing to appreciate the mereological fallacy, this is a case of teaching your grandmother to suck eggs. I am familiar with the point, having pioneered its use. Did I, perhaps, lose my way when I left Oxford?" (77)

I am now turning to Searle's essay "Putting Consciousness Back In The Brain: Reply to Bennett and Hacker."

B&H then reply back.

It makes for good reading, and a good albeit very technical introduction to one of the discussions of our day.