Astonishing Hypothesis Psychology

[Chapin Ratte]

ProfessorPaul 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."

Now, you might have different views around--People around this roomwill have different views as to whether reincarnation really exists,but we can imagine it. We could imagine a person dying and thenreemerging in another body. This is not Hollywood invention. One of thegreat short stories of the last century begins with a sentence by FranzKafka: "As Gregor Samsa woke one morning from uneasy dreams, he foundhimself transformed in his bed into a gigantic insect." And again,Kafka invites us to imagine waking up into a body of a cockroach and wecan. This is also not modern. Hundreds of years before the birth ofChrist, Homer described the fate of the companions of Odysseus who weretransformed by a witch into pigs. Actually, that's not quite right. Shedidn't turn them into pigs. She did something worse. She stuck them inthe bodies of pigs. They had the head and voice and bristles and bodyof swine but their minds remained unchanged as before, so they werepenned there weeping. And we are invited to imagine the fate of againfinding ourselves in the bodies of other creatures and, if you canimagine this, this is because you are imagining what you are asseparate from the body that you reside in.

Finally, most people around the world, all religions and most peoplein most countries at most times, believe that people can survive thedestruction of their bodies. Now, cultures differ according to the fateof the body. Some cultures have the body going to--sorry--the fate ofthe soul. Some cultures have you going to Heaven or descending to Hell.Others have you occupying another body. Still, others have youoccupying an amorphous spirit world. But what they share is the ideathat what you are is separable from this physical thing you carryaround. And the physical thing that you carry around can be destroyedwhile you live on.

These views are particularly common in the United States. In onesurvey done in Chicago a few years ago, people were asked theirreligion and then were asked what would happen to them when they died.Most people in the sample were Christian and about 96% of Christianssaid, "When I die I'm going to go to Heaven." Some of the sample wasJewish. Now, Judaism is actually a religion with a less than clearstory about the afterlife. Still, most of the subjects who identifiedthemselves as Jewish said when they die they will go to Heaven. Some ofthe sampled denied having any religion at all--said they have noreligion at all. Still, when these people were asked what would happenwhen they would die, most of them answered, "I'm going to go toHeaven."

So, dualism is emmeshed. A lot rests on it but, as Crick points out;the scientific consensus now is that dualism is wrong. There is no"you" separable or separate from your body. In particular, there is no"you" separable from your brain. To put it the way cognitive scientistsand psychologists and neuroscientists like to put it, "the mind is whatthe brain does." The mind reflects the workings of the brain just likecomputation reflects the working of a computer. Now, why would you holdsuch an outrageous view? Why would you reject dualism in favor of thisalternative? Well, a few reasons. One reason is dualism has always hadits problems. For one thing, it's a profoundly unscientific doctrine.We want to know as curious people how children learn language, what wefind attractive or unattractive, and what's the basis for mentalillness. And dualism simply says, "it's all nonphysical, it's part ofthe ether," and hence fails to explain it.

More specifically, dualists like Descartes struggle to explain how aphysical body connects to an immaterial soul. What's the conduit? Howcould this connection be made? After all, Descartes knew full well thatthere is such a connection. Your body obeys your commands. If you bangyour toe or stub your toe you feel pain. If you drink alcohol itaffects your reasoning, but he could only wave his hands as to how thisphysical thing in the world could connect to an immaterial mind.

Descartes, when he was alive, was reasonable enough concluding thatphysical objects cannot do certain things. He was reasonable enough inconcluding, for instance, as he did, that there's no way a merelyphysical object could ever play a game of chess because--and that sucha capacity is beyond the capacity of the physical world and hence youhave to apply--you have to extend the explanation to an immaterial soulbut now we know--we have what scientists call an existence proof. Weknow physical objects can do complicated and interesting things. Weknow, for instance, machines can play chess. We know machines canmanipulate symbols. We know machines have limited capacities to engagein mathematical and logical reasoning, to recognize things, to dovarious forms of computations, and this makes it at least possible thatwe are such machines. So you can no longer say, "Look. Physical thingsjust can't do that" because we know physical things can do a lot andthis opens up the possibility that humans are physical things, inparticular, that humans are brains.

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