Rationality

12/02/2011 by admin.

Another answer to the Edge question (here), has intrigued me. This one is written by Alison Gopnik, the author of The Philosophical Baby. She rejects the usual image of the unconscious and replaces it by a very rational mind.

One of the greatest scientific insights of the twentieth century was that most psychological processes are not conscious. But the “unconscious” that made it into the popular imagination was Freud’s irrational unconscious — the unconscious as a roiling, passionate id, barely held in check by conscious reason and reflection. This picture is still widespread even though Freud has been largely discredited scientifically.

She draws a picture of Turing’s rational unconscious.

Alan Turing, the father of the modern computer, began by thinking about the highly conscious and deliberate step-by-step calculations performed by human “computers” like the women decoding German ciphers at Bletchley Park. His first great insight was that the same processes could be instantiated in an entirely unconscious machine with the same results. A machine could rationally decode the German ciphers using the same steps that the conscious “computers” went through. And the unconscious relay and vacuum tube computers could get to the right answers in the same way that the flesh and blood ones could. … Turing’s second great insight was that we could understand much of the human mind and brain as an unconscious computer too.

… More recently, cognitive scientists have added the idea of probability into the mix, so that we can describe an unconscious mind, and design a computer, that can perform feats of inductive as well as deductive inference. Using this sort of probabilistic logic a system can accurately learn about the world in a gradual, probabilistic way, raising the probability of some hypotheses and lowering that of others, and revising hypotheses in the light of new evidence. This work relies on a kind of reverse engineering. First work out how any rational system could best infer the truth from the evidence it has. Often enough, it will turn out that the unconscious human mind does just that.

… The Freudian picture identifies infants with that fantasizing, irrational unconscious, and even on the classic Piagetian view young children are profoundly illogical. But contemporary research shows the enormous gap between what young children say, and presumably what they experience, and their spectacularly accurate if unconscious feats of learning, induction and reasoning. The rational unconscious gives us a way of understanding how babies can learn so much when they consciously seem to understand so little. …

I like the portrait of the unconscious mind as being workman-like processes to produce movement, preception etc. and not a leftover Freudian construct. I have three problems, only little nitpicking ones, with her picture. First I think the metaphor between brain and computer is overused these days and the idea that the brain is a Turing computer is a stretch too far. She doesn’t say it is, but comes very close. Second, I find ‘rationality’ is maybe a misleading word for the what I see as the appropriateness to a living organism of the brain’s processes. Rationality, in ordinary use, implies a sort of mathematical purity without attention given to values, emotions and significances. And finally, she appears to give room for a conscious mind separate from an unconscious one, although she never actually says this. I prefer the model: we have a single mind, part of its processing is constructing consciousness, only a small part of thought reaches conscious awareness.

Despite my small reservations, this piece is so refreshing a take on thought.

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