proper, Introduction to Psychology, with a discussion

about the brain. And, in particular,

I want to lead off the class with an idea that the Nobel

Prize winning biologist, Francis Crick,

described as "The Astonishing Hypothesis."

And The Astonishing Hypothesis is summarized like this.

As he writes, The Astonishing Hypothesis 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

behavior of a vast assembly of nerve cells and their associated

molecules. As Lewis Carroll's Alice might

have phrased it, "you're nothing but a pack of

neurons." It is fair to describe this as

astonishing. It is an odd and unnatural view

and I don't actually expect people to believe it at first.

It's an open question whether you'll believe it when this

class comes 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.

Most people are dualists. Now, dualism is a very

different doctrine. It's a doctrine that can be

found in every religion and in most philosophical systems

throughout history. It was very explicit in Plato,

for instance. But the most articulate and

well-known defender of dualism is the philosopher Rene

Descartes, and Rene Descartes explicitly

asked a question, "Are humans merely physical

machines, merely physical things?"

And he answered, "no." He agreed that animals are

machines. In fact, he called them "beast

machines" and said animals, nonhuman animals are merely

robots, but people are different.

There's a duality of people. Like animals,

we possess physical material bodies, but unlike animals,

what we are is not physical. We are immaterial souls that

possess physical bodies, that have physical bodies,

that reside in physical bodies, that connect to physical

bodies. So, this is known as dualism

because the claim is, for humans at least,

there are two separate things; there's our material bodies and

there's our immaterial minds. Now, Descartes made two

arguments for dualism. One argument involved

observations of a human action. So, Descartes lived in a fairly

sophisticated time, and his time did have robots.

These were not electrical robots, of course.

They were robots powered by hydraulics.

So, Descartes would walk around the French Royal Gardens and the

French Royal Gardens were set up like a seventeenth-century

Disneyland. They had these characters that

would operate according to water flow and so if you stepped on a

certain panel, a swordsman would jump out with

a sword. If you stepped somewhere else,

a bathing beauty would cover herself up behind some bushes.

And Descartes said, "Boy, these machines respond in

certain ways to certain actions so machines can do certain

things and, in fact," he says,

"our bodies work that way too. If you tap somebody on the

knee, your leg will jump out. Well, maybe that's what we are."

But Descartes said that can't be because there are things that

humans do that no machine could ever do.

Humans are not limited to reflexive action.

Rather, humans are capable of coordinated, creative,

spontaneous things. We can use language,

for instance, and sometimes my use of

language can be reflexive. Somebody says, "How are you?"

And I say, "I am fine. How are you?"

But sometimes I could say what I choose to be,

"How are you?" "Pretty damn good."

I can just choose. And machines,

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 the method. This he came to using the

method of doubt. So, he started asking 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 a God.

I believe I live in a rich country but maybe I've been

fooled." He even said,

"I believe I have had friends and family but maybe I am being

tricked. Maybe an evil demon,

for instance, has tricked me,

has deluded me into thinking I have experiences that aren't

real." And, of course,

the modern version of this is The Matrix.

The idea of The Matrix is explicitly built upon

Cartesian--Descartes' worries about an evil demon.

Maybe everything you're now experiencing is not real,

but rather is the product of some other, perhaps malevolent,

creature. Descartes, similarly,

could doubt he has a body. In fact, he noticed that madmen

sometimes believe they have extra limbs or they believe

they're of different sizes and shapes than 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 think I'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, Descartes concluded,

that he cannot doubt, and the answer is he cannot

doubt that he is himself thinking.

That would be self-refuting. And so, Descartes used the

method of doubt to say there's something really different about

having a body that's always uncertain from having a mind.

And he used this argument as a way to support dualism,

as a way to support the idea that bodies and minds are

separate. And so he concluded,

"I knew that I was a substance, the whole essence or nature of

which is to think, and that for its existence,

there is no need of any place nor does it depend on any

material thing. That is to say,

the soul by which I am, when I am, is entirely distinct

from body." Now, I said before that this is

common sense and I want to illustrate the common sense

nature of this in a few ways. One thing is our dualism is

enmeshed in our language. So, we have a certain mode of

talking about things that we own or things that are close to us

– my arm, my heart, my child,

my car – but we also extend that to my body and my brain.

We talk about owning our brains as if we're somehow separate

from them. Our dualism shows up in

intuitions about personal identity.

And what this means is that common sense tells us that

somebody can be the same person even if their body undergoes

radical and profound changes. The best examples of this are

fictional. So, we have no problem

understanding a movie where somebody goes to sleep as a

teenager and wakes up as Jennifer Garner,

as an older person. Now, nobody says,

"Oh, that's a documentary. I believe that thoroughly true"

but at the same time nobody, no adult, no teenager,

no child ever leaves and says, "I'm totally conceptually

confused." Rather, we follow the story.

We can also follow stories which involve more profound

transformations as when a man dies and is reborn into the body

of a child. Now, you might have different

views around--People around this room will have different views

as to whether reincarnation really exists,

but we can imagine it. We could imagine a person dying

and then reemerging in another body.

This is not Hollywood invention. One of the great short stories

of the last century begins with a sentence by Franz Kafka:

"As Gregor Samsa woke one morning from uneasy dreams,

he found himself transformed in his bed into a gigantic insect."

And again, Kafka invites us to imagine waking up into a body of

a cockroach and we can. This is also not modern.

Hundreds of years before the birth of Christ,

Homer described the fate of the companions of Odysseus who were

transformed by a witch into pigs.

Actually, that's not quite right.

She didn't turn them into pigs. She did something worse.

She stuck them in the bodies of pigs.

They had the head and voice and bristles and body of swine but

their minds remained unchanged as before, so they were penned

there weeping. And we are invited to imagine

the fate of again finding ourselves in the bodies of other

creatures and, if you can imagine this,

this is because you are imagining what you are as

separate from the body that you reside in.

We allow for the notion that many people can occupy one body.

This is a mainstay of some slapstick humor including the

classic movie, All of Me--Steve Martin

and Lily Tomlin – highly recommended.

But many people think this sort of thing really happens.

One analysis of multiple personality disorder is that you

have many people inside a single body fighting it out for

control. Now, we will discuss multiple

personality disorder towards the end of the semester and it turns

out things are a good deal more complicated than this,

but still my point isn't about how it really is but how we

think about it. Common sense tells us you could

have more than one person inside a single body.

This shows up in a different context involving exorcisms

where many belief systems allow for the idea that people's

behavior, particularly their evil or

irrational behavior, could be because something else

has taken over their bodies. Finally, most people around the

world, all religions and most people in most countries at most

times, believe that people can survive

the destruction of their bodies. Now, cultures differ according

to the fate of the body. Some cultures have the body

going to--sorry--the fate of the soul.

Some cultures have you going to Heaven or descending to Hell.

Others have you occupying another body.

Still, others have you occupying an amorphous spirit

world. But what they share is the idea

that what you are is separable from this physical thing you

carry around. And the physical thing that you

carry around can be destroyed while you live on.

These views are particularly common in the United States.

In one survey done in Chicago a few years ago,

people were asked their religion and then were asked

what would happen to them when they died.

Most people in the sample were Christian and about 96% of

Christians said, "When I die I'm going to go to

Heaven." Some of the sample was Jewish.

Now, Judaism is actually a religion with a less than clear

story about the afterlife. Still, most of the subjects who

identified themselves as Jewish said when they die they will go

to Heaven. Some of the sampled denied

having any religion at all--said they have no religion at all.

Still, when these people were asked what would happen when

they would die, most of them answered,

"I'm going to go to Heaven." 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

scientists and psychologists and neuroscientists like to put it,

"the mind is what the brain does."

The mind reflects the workings of the brain just like

computation reflects the working of a computer.

Now, why would you hold such an outrageous view?

Why would you reject dualism in favor of this alternative?

Well, a few reasons. One reason is dualism has

always had its problems. For one thing,

it's a profoundly unscientific doctrine.

We want to know as curious people how children learn

language, what we find attractive or unattractive,

and what's the basis for mental illness.

And dualism simply says, "it's all nonphysical,

it's part of the ether," and hence fails to explain it.

More specifically, dualists like Descartes

struggle to explain how a physical body connects to an

immaterial soul. What's the conduit?

How could this connection be made?

After all, Descartes knew full well that there is such a

connection. Your body obeys your commands.

If you bang your toe or stub your toe you feel pain.

If you drink alcohol it affects your reasoning,