The Astonishing Hypothesis

[Carlee Members]

Thedeath of Francis Crick at the end of last month drew many eulogies, most of which naturally highlighted the discovery of the double helix structure of DNA. In the latter part of his life, however, Crick turned his attention to the problem of consciousness rather than genetics or microbiology. He seems to have been temperamentally inclined to working in collaboration with a partner - having cracked the mystery of DNA with Watson, he now developed a fruitful partnership with Christof Koch. His view of consciousness, however, was summed up in his own book 'The Astonishing Hypothesis'.

The hypothesis in question is '...that "You", your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behaviour of a vast assembly of nerve cells and their associated molecules.'

It has been suggested by some that this is not such an astonishing hypothesis after all. Certainly the idea that our mental life arises from the activity of the brain has been a mainstream one for a considerable time, but the key words in Crick's hypothesis are perhaps 'no more than'. On the face of it, this is indeed a fairly extreme claim; a reductionism which stops just short of denying the actual existence of consciousness. The quotation marks around the word 'You' suggest that Crick was also tempted by scepticism about the self.

It's difficult to be absolutely clear about Crick's philosophical position, however. Searle criticised 'The Astonishing Hypothesis' for not being clear about exactly what kind of reductionism it was putting forward, and with some justice: at times Crick talks in terms of emergence, and he seems to want to disavow naive or eliminativist reductionism, but his bottom line does seem to be that consciousness is nothing more than the activity of neurons.

One reason for this lack of clarity is perhaps that Crick, as he very fairly points out, is not even trying to set out a finished theory, only a hypothesis and a suggested line of attack. But the fundamental reason is that Crick is really interested in telling a scientific story, not a philosophical one. Most of the book is taken up with doing this. Crick's strategy is to approach consciousness via a consideration of the faculty of vision. He gives a very clear and interesting account of research in this area, with a well-judged balance of speculation and caution. Personally, however, I think the focus on vision dooms the enterprise from the start, at least as far as consciousness is concerned. The best one can hope to get by investigating vision alone is some insight into attention and sensory awareness; the central issues of consciousness are likely to remain untouched. Blind people are fully conscious, after all!

It's also true that Crick's close focus on neurons at the expense of philosophy seems to lead him into some dubious positions. He and Koch are particularly known for the view that consciousness arises when sets of neurons fire in a co-ordinated way, at frequencies around 40 Hertz. Crick suggests that synchronised firing of this kind might, in particular, be the neural correlate of visual awareness. To be really consistent with Crick's general attitude, the firing really needs to be visual awareness, not just correlated with it, but that is perhaps a nit-picking point: the more fundamental difficulty is that no explanation is ever offered as to why co-ordinated firing should give rise to conscious experience. Crick suggests that this kind of co-ordination might be the answer to the notorious binding problem, because it explains how neurons in different visual areas which respond to different qualities of the seen object (form colour, motion, etc) 'temporarily become active as a unit', but it seems that at best that might be part of the answer. A particularly difficult aspect of the problem is that different pieces of sensory data which relate to the same object don't arrive in one place in the brain at the same time, yet our conscious experience never seems to suffer from, as it were, faulty lip sync. It's hard to see how simultaneous patterns of firing could deal with the chronological problem.

At the end of the book, Crick offers a short and tentative postscript setting out an idea about free will. This is really an explanation for why people think they have free will - Crick is presumably a determinist. His idea is that there is an unconscious part of the brain which makes the plans for what we are going to do: these plans then pop into the conscious mind as if from nowhere, giving an impression of free will. The conscious mind may be able to guess the factors behind the plans, or it may get them wrong: either way, it feels there is some mystery about the process. Crick, drawing on some research by Damasio, goes so far as to suggest that this unconscious planning facility (the 'seat of the will') is probably located in or near the anterior cingulate sulcus.

Professor Paul Bloom: We're going to begin the class proper,Introduction to Psychology, with a discussion about the brain. And, inparticular, I want to lead off the class with an idea that the NobelPrize winning biologist, Francis Crick, described as "The AstonishingHypothesis." And The Astonishing Hypothesis is summarized like this. Ashe writes, The Astonishing Hypothesis is that:

It is fair to describe this as astonishing. It is an odd andunnatural view and I don't actually expect people to believe it atfirst. It's an open question whether you'll believe it when this classcomes to an end, but I'd be surprised if many of you believe it now.Most people don't. Most people, in fact, hold a different view. Mostpeople are dualists. Now, dualism is a very different doctrine. It's adoctrine that can be found in every religion and in most philosophicalsystems throughout history. It was very explicit in Plato, forinstance.

But the most articulate and well-known defender of dualism is thephilosopher Rene Descartes, and Rene Descartes explicitly asked aquestion, "Are humans merely physical machines, merely physicalthings?" And he answered, "no." He agreed that animals are machines. Infact, he called them "beast machines" and said animals, nonhumananimals are merely robots, but people are different. There's a dualityof people. Like animals, we possess physical material bodies, butunlike animals, what we are is not physical. We are immaterial soulsthat possess physical bodies, that have physical bodies, that reside inphysical bodies, that connect to physical bodies. So, this is known asdualism because the claim is, for humans at least, there are twoseparate things; there's our material bodies and there's our immaterialminds.

Now, Descartes made two arguments for dualism. One argument involvedobservations of a human action. So, Descartes lived in a fairlysophisticated time, and his time did have robots. These were notelectrical robots, of course. They were robots powered by hydraulics.So, Descartes would walk around the French Royal Gardens and the FrenchRoyal Gardens were set up like a seventeenth-century Disneyland. Theyhad these characters that would operate according to water flow and soif you stepped on a certain panel, a swordsman would jump out with asword. If you stepped somewhere else, a bathing beauty would coverherself up behind some bushes. And Descartes said, "Boy, these machinesrespond in certain ways to certain actions so machines can do certainthings and, in fact," he says, "our bodies work that way too. If youtap somebody on the knee, your leg will jump out. Well, maybe that'swhat we are." But Descartes said that can't be because there are thingsthat humans do that no machine could ever do. Humans are not limited toreflexive action. Rather, humans are capable of coordinated, creative,spontaneous things. We can use language, for instance, and sometimes myuse of language can be reflexive. Somebody says, "How are you?" And Isay, "I am fine. How are you?" But sometimes I could say what I chooseto be, "How are you?" "Pretty damn good." I can just choose. Andmachines, Descartes argued, are incapable of that sort of choice.Hence, we are not mere machines.

The second argument is, of course, quite famous and this was themethod. This he came to using the method of doubt. So, he startedasking himself the question, "What can I be sure of?" And he said,"Well, I believe there's a God, but honestly, I can't be sure there's aGod. I believe I live in a rich country but maybe I've been fooled." Heeven said, "I believe I have had friends and family but maybe I ambeing tricked. Maybe an evil demon, for instance, has tricked me, hasdeluded me into thinking I have experiences that aren't real." And, ofcourse, the modern version of this is The Matrix.

The idea of The Matrix is explicitly built uponCartesian--Descartes' worries about an evil demon. Maybe everythingyou're now experiencing is not real, but rather is the product of someother, perhaps malevolent, creature. Descartes, similarly, could doubthe has a body. In fact, he noticed that madmen sometimes believe theyhave extra limbs or they believe they're of different sizes and shapesthan they really are and Descartes said, "How do I know I'm not crazy?Crazy people don't think they're crazy so the fact that I don't thinkI'm crazy doesn't mean I'm not crazy. How do I know," Descartes said,"I'm not dreaming right now?" But there is one thing, Descartesconcluded, that he cannot doubt, and the answer is he cannot doubt thathe is himself thinking. That would be self-refuting. And so, Descartesused the method of doubt to say there's something really differentabout having a body that's always uncertain from having a mind. And heused this argument as a way to support dualism, as a way to support theidea that bodies and minds are separate. And so he concluded, "I knewthat I was a substance, the whole essence or nature of which is tothink, and that for its existence, there is no need of any place nordoes it depend on any material thing. That is to say, the soul by whichI am, when I am, is entirely distinct from body."

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