Consciousness and the brain | John Searle | TEDxCERN
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0:31 - 0:34I am going to talk about consciousness.
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0:34 - 0:35Why consciousness?
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0:35 - 0:37It is curiously a neglected subject
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0:37 - 0:41both in our scientific
and our philosophical culture. -
0:41 - 0:42Why is that curious?
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0:42 - 0:48It's most important aspect of our lives
for a very simple logical reason, -
0:48 - 0:51namely, it is a necessary condition
on anything being important in our lives -
0:51 - 0:53that we are conscious.
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0:53 - 0:56[If] you care about science,
philosophy, music, art, whatever, -
0:56 - 0:59it is no good if you are
a zombie or in a coma, right? -
0:59 - 1:01So consciousness is number one.
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1:01 - 1:05That's the first reason
[that] we are talking about it. -
1:05 - 1:09The second reason is that when people
do get interested in it, -
1:09 - 1:10as I think they should,
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1:10 - 1:12they tend to say
the most appalling things! -
1:12 - 1:15I am not going to attempt
to conceal from you -
1:15 - 1:18some of the most appalling things
that have been said about it; -
1:18 - 1:21and even when they are not saying
appalling things -
1:21 - 1:23[and] they are really trying
to do serious research, -
1:23 - 1:27well, it's been slow,
progress has been slow. -
1:27 - 1:31Let me tell you a little bit
about some of the difficulties. -
1:31 - 1:33When I first got interested
in this, I thought -
1:33 - 1:35it's a straightforward problem in biology
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1:35 - 1:38[so] let's get these brain stabbers
to get busy -
1:38 - 1:40and figure out how it works in the brain.
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1:40 - 1:43I went over to UCSF and talked
to all heavy-duty neurologists there -
1:43 - 1:45and they showed some impatience,
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1:45 - 1:49as scientists often do when you ask them
embarrassing questions, -
1:49 - 1:51and the thing that struck me
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1:51 - 1:54is that a very famous neurobiologist
said exasperated: -
1:54 - 1:58"Look, in my discipline,
it's OK to be interested in consciousness, -
1:58 - 2:00but get tenure first!
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2:00 - 2:02(Laughter)
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2:02 - 2:04I've been working on this for a long time
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2:04 - 2:07and now you might actually get tenure
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2:07 - 2:10by working on consciousness,
and if so, that's a real step forward! -
2:10 - 2:13Why then, is this curious reluctance
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2:13 - 2:16and curious hostility to consciousness?
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2:16 - 2:19I think it's a combination of two features
of our intellectual culture -
2:19 - 2:22that like to think
they are opposing each other -
2:22 - 2:26but in fact they share
a common set of assumptions. -
2:26 - 2:29Consciousness is not a part
of the physical world -
2:29 - 2:33but it's part of the spiritual world,
it belongs to the soul, -
2:33 - 2:36and the soul is not a part
of the physical world. -
2:36 - 2:39That's the tradition of God,
the soul, and immortality. -
2:39 - 2:42There is another tradition
that is opposed to this -
2:42 - 2:43but excepts the worst assumption.
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2:43 - 2:47That tradition thinks
we are heavy-duty scientific materialists, -
2:47 - 2:50consciousness is not a part
of the physical world, -
2:50 - 2:53either it doesn't exist at all
or it is something else, -
2:53 - 2:56a computer program
or some damn fool thing. -
2:56 - 2:57(Laughter)
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2:57 - 2:59But in any case, it's not part of science!
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2:59 - 3:02I used to get in an argument
that really gave me a stomachache. -
3:02 - 3:03Here is how it went:
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3:03 - 3:07"Science is objective,
consciousness is subjective, -
3:07 - 3:10therefore, there cannot be
a science of consciousness." -
3:10 - 3:11I love that argument
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3:11 - 3:14because it has got
a wonderful fallacy of ambiguity -
3:14 - 3:16over the concept of objectivity.
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3:16 - 3:18And I have already used up too much time
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3:18 - 3:21just to clearing my breath,
sort of speak, -
3:21 - 3:22but I want to get to that.
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3:24 - 3:28These twin traditions are paralyzing us,
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3:28 - 3:31and it's very hard to get out
of these twin traditions, -
3:31 - 3:34and I have only one real message
in this lecture, -
3:34 - 3:35and that is consciousness
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3:35 - 3:38is a biological phenomenon,
like photosynthesis, -
3:38 - 3:43digestion, mitosis,
and all that biological phenomena. -
3:43 - 3:44And once you accept that,
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3:44 - 3:46most, though not all,
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3:46 - 3:48of the hard problems about consciousness
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3:48 - 3:50simply evaporate!
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3:50 - 3:52And I will go through some of them.
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3:52 - 3:54I promised you to tell you
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3:54 - 3:56some of the outrageous things
said about consciousness, -
3:56 - 4:01and because of shortage of time,
I will only mention four of the worst. -
4:01 - 4:05One: "Consciousness does not exist.
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4:05 - 4:07It is an illusion, like sunsets."
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4:07 - 4:12Science has shown sunsets
and rainbows are illusions, -
4:12 - 4:14so consciousness is an illusion.
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4:14 - 4:17Two: "Maybe it exists,
but it is really something else, -
4:17 - 4:21it's a computer program
running in the brain." -
4:21 - 4:25Three: "No, the only thing
that exists is really behavior!" -
4:25 - 4:29It's embarrassing
how influential behaviorism was, -
4:29 - 4:30but I will get back to that.
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4:30 - 4:32Four: "Maybe consciousness exists,
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4:32 - 4:35but it can't make
any difference to the world. -
4:35 - 4:37How could spirituality move anything?"
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4:37 - 4:39And whenever somebody
tells me that, I think: -
4:39 - 4:42"You want to see if spirituality
moves something? Watch!" -
4:42 - 4:47I decide consciously to raise my arm
and the damn thing goes up. -
4:47 - 4:48(Laughter)
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4:48 - 4:50(Applause)
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4:50 - 4:55Furthermore, we do not say:
"It's a bit like the weather in Geneva, -
4:55 - 4:58some days it goes up
and some days it doesn't go up." -
4:58 - 4:59No! It goes up
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4:59 - 5:01when I right damn well want it to!
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5:01 - 5:03I will tell you how that is possible.
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5:03 - 5:06Now, I haven't yet given you a definition,
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5:06 - 5:09you can't do this
if you don't give a definition. -
5:09 - 5:12People always say: "Consciousness
is very hard to define." -
5:12 - 5:13I think it is rather easy to define
-
5:13 - 5:16if you are not trying to give
a scientific definition. -
5:16 - 5:18We are not ready
for a scientific definition, -
5:18 - 5:20but here is the common sense definition:
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5:20 - 5:25consciousness consists of all those states
of feelings, or sensations, or awareness; -
5:25 - 5:28it begins in the morning
when you wake up from a dream, -
5:28 - 5:32and it goes on all day,
until you fall asleep, or die, -
5:32 - 5:34or otherwise become unconscious.
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5:34 - 5:37Dreams are a form
of consciousness on this definition. -
5:37 - 5:40That's the common sense definition,
that's our target; -
5:40 - 5:44if you are not talking about that,
you are not talking about consciousness. -
5:44 - 5:45But they think:"Well, that's it!
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5:45 - 5:47That's an awful problem!
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5:47 - 5:51How can such thing exist
as part of the real world?" -
5:51 - 5:53And this, if you have ever had
a philosophy course, -
5:53 - 5:56this is known
as the famous "mind-body problem." -
5:56 - 6:00I think that has a simple solution to it
and I am going to give it to you. -
6:00 - 6:00And here it is:
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6:00 - 6:04all of our conscious states,
without exception, are caused -
6:04 - 6:08by lower-level neurobiological processes
in the brain. -
6:08 - 6:13And they are realized in the brain
as higher-level or system features. -
6:13 - 6:17It is about as mysterious
as the liquidity of water, right? -
6:17 - 6:19The liquidity is not an extra juice
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6:19 - 6:22squirted out by the H2O molecules,
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6:22 - 6:25it's a condition that the system is in.
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6:25 - 6:30And just as the jar full of water
can go from liquid to solid, -
6:30 - 6:32depending on the behavior
of the molecules, -
6:32 - 6:35so your brain can go
from a state of being conscious -
6:35 - 6:37to a state of being unconscious,
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6:37 - 6:40depending on the behavior
of the molecules. -
6:40 - 6:44The famous "mind-body problem"
is that simple. -
6:45 - 6:47But now, we get
into some harder questions. -
6:49 - 6:53Let's specify
the exact features of consciousness -
6:53 - 6:56so that we can then answer
those four objections that I made to it. -
6:56 - 7:00Well, the first feature is
it is real and irreducible. -
7:00 - 7:02You can't get rid of it.
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7:02 - 7:07You see, the distinction
between reality and illusion -
7:07 - 7:11is the distinction between how things
consciously seem to us -
7:11 - 7:13and how they really are.
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7:13 - 7:15If consciousness seems like...
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7:15 - 7:19I like the French "arch",
it seems like there's an arch in the sky, -
7:19 - 7:22or it seems like the sun
is setting over the mountains, -
7:22 - 7:24it consciously seems to us
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7:24 - 7:26but that's not really happening.
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7:26 - 7:27But for that distinction,
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7:27 - 7:30between how things consciously seem
and how they really are, -
7:30 - 7:35you can't make that distinction
for the very existence of consciousness. -
7:35 - 7:38Because we are
the very existence of consciousness: -
7:38 - 7:41if it consciously seems to you,
that you are conscious, -
7:41 - 7:43you are conscious!
-
7:43 - 7:44(Laughter)
-
7:44 - 7:46I mean if a bunch of experts
come to me and say: -
7:46 - 7:50"We are heavy-duty neurobiologists
and we've done a study on you Searle," -
7:50 - 7:52and we are convinced
you are not conscious. -
7:52 - 7:55You're a very cleverly constructed robot."
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7:55 - 7:57I don't think: " Well, maybe
these guys are right!" -
7:57 - 7:59I don't think that for a moment!
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7:59 - 8:02Because, I mean, Descartes
may have made a lot of mistakes -
8:02 - 8:03but he is right about this:
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8:03 - 8:06you cannot doubt the existence
of your own consciousness. -
8:06 - 8:08That's the first feature of consciousness.
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8:08 - 8:10It is real and irreducible.
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8:10 - 8:13You cannot get rid of it
by showing that it's an illusion, -
8:13 - 8:16in a way that you can
with other standard illusions. -
8:16 - 8:19The second feature is this one
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8:19 - 8:21that has been such a source
of trouble to us. -
8:21 - 8:23And that is all of our conscious states
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8:23 - 8:26have this qualitative character to them;
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8:26 - 8:29there is something
that it feels like to drink beer, -
8:29 - 8:32which is not what feels like
to do your income tax, -
8:32 - 8:33or listen to music.
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8:33 - 8:37And this qualitative field
automatically generates a third feature, -
8:37 - 8:41namely, conscious states
are by definition subjective, -
8:41 - 8:43in the sense that they only exist
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8:43 - 8:46as experienced
by some human or animal subjects, -
8:46 - 8:48some self that experiences them.
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8:48 - 8:50Maybe we will be able
to build a conscious machine, -
8:50 - 8:53[but] since we don't know
how our brains do it, -
8:53 - 8:57we are not in the position, so far,
to build a conscious machine. -
8:57 - 8:59Okay, another feature of consciousness
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8:59 - 9:03is that it comes
in unified conscious fields. -
9:03 - 9:06I don't just have the sight
of people in front of me, -
9:06 - 9:07and the sound of my voice,
-
9:07 - 9:10and the weight of my shoes
against the floor, -
9:10 - 9:14but they occur to me as part
of one single great conscious field -
9:14 - 9:16that stretches forward and backward.
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9:16 - 9:20That is the key to understanding
the enormous power of consciousness. -
9:20 - 9:24And we have not been able
to do that in a robot. -
9:24 - 9:26The disappointment of robotics
derives from the fact -
9:26 - 9:29that we don't know
how to make a conscious robot, -
9:29 - 9:32so we don't have a machine
that can do this kind of thing. -
9:32 - 9:34The next feature of consciousness
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9:34 - 9:37after this marvelous,
unified conscious field -
9:37 - 9:40is that it functions causally
in our behavior. -
9:40 - 9:43I gave you a scientific demonstration
by raising my hand, -
9:43 - 9:45but how is that possible?
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9:45 - 9:49How can it be
that this thought in my brain -
9:49 - 9:51can move material objects?
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9:51 - 9:53Well, I will tell you the answer.
-
9:53 - 9:55--we don't know the detailed answer,
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9:55 - 9:57but we know the basic part of the answer--
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9:57 - 9:59and that is there are sequences
of neuron firings -
9:59 - 10:03and they terminate
where the acetylcholine is secreted -
10:03 - 10:05at the axon end-plates
of the motor neurons, -
10:05 - 10:08sorry to use
philosophical terminology here. -
10:08 - 10:09(Laughter)
-
10:09 - 10:10But when it is secreted
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10:10 - 10:12at the axon end-plates
of the motor neurons, -
10:12 - 10:15a lot of wonderful things
happen in the ion channels -
10:15 - 10:17and the damned arm goes up.
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10:17 - 10:19And think of what I have told you.
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10:19 - 10:20One and the same event,
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10:20 - 10:23my conscious decision to raise my hand
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10:23 - 10:25has a level of description
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10:25 - 10:28where it has all of these touchy-feely,
spiritual qualities, -
10:28 - 10:30--it's a thought in my brain--
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10:30 - 10:31but at the same time,
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10:31 - 10:33it's busy secreting acetylcholine
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10:33 - 10:35and doing all sorts of other things
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10:35 - 10:37as it makes its way from the motor cortex
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10:37 - 10:40down through the nerves fibers
and the arm. -
10:40 - 10:44Now, what that tells us
is that our traditional vocabularies -
10:44 - 10:48for discussing these issues,
are totally obsolete! -
10:48 - 10:49One and the same event,
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10:49 - 10:52has a level of description
where's neurobiological, -
10:52 - 10:55and another level of description
where's mental, -
10:55 - 10:56and that's a single event
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10:56 - 10:57and that's how nature works,
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10:57 - 11:02that's how is possible
for consciousness to function causally. -
11:02 - 11:04Now, with that in mind,
-
11:04 - 11:07with going through these various features
of consciousness, -
11:07 - 11:10let's go back and answer
some of those early objections. -
11:10 - 11:14Well, the first one I said,
was consciousness doesn't exist, -
11:14 - 11:15it's an illusion.
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11:15 - 11:16Well, I've already answered that
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11:16 - 11:19I don't think we need to worry about that.
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11:19 - 11:21But the second one,
had an incredible influence -
11:21 - 11:23and may still be around,
and that is -
11:23 - 11:26if consciousness exists,
it's really something else; -
11:26 - 11:29it's really a digital computer program
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11:29 - 11:30running in your brain,
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11:30 - 11:33and that's what we need to do
to create consciousness, -
11:33 - 11:34get the right program.
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11:34 - 11:37Forget about the hardware,
any hardware will do, -
11:37 - 11:40provided is rich enough and stable enough
to carry the program. -
11:40 - 11:42Now, we know that that's wrong.
-
11:42 - 11:45I mean, anybody who's thought
about computers at all -
11:45 - 11:47can see that that's wrong.
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11:47 - 11:50Because computation is defined
as symbol manipulation, -
11:50 - 11:53usually thought as 0s and 1s,
but any symbols will do. -
11:53 - 11:54You get an algorithm
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11:54 - 12:00that you can program in a binary code
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12:00 - 12:04and that's the defining trait
of the computer program. -
12:04 - 12:08But we know that's purely syntactical,
that's symbolic, -
12:08 - 12:11we know that actual human consciousness
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12:11 - 12:14has something more than that,
it's got a content, -
12:14 - 12:17in addition to the syntax,
it's got a semantics. -
12:17 - 12:19I made that argument,
-
12:19 - 12:21--oh, my god!
I don't want to think about it!-- -
12:21 - 12:22more that 30 years ago,
-
12:22 - 12:25but there is a deeper argument
implicit in what I've told you. -
12:25 - 12:28And I want to tell you that argument
briefly, and that is: -
12:29 - 12:33consciousness creates an observer
independent reality. -
12:33 - 12:36It creates a reality of money,
property, government, -
12:36 - 12:39marriage, CERN, conferences,
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12:39 - 12:44cocktail parties, and summer vacations.
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12:44 - 12:46And all of those
are creations of consciousness. -
12:46 - 12:48Their existence is observer-relative.
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12:48 - 12:51It's only relative to conscious agents;
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12:51 - 12:53that a piece of paper is a money,
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12:53 - 12:55or a bunch of buildings is a university.
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12:55 - 12:58Now, ask yourselves about computation.
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12:58 - 13:00Is that absolute?
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13:00 - 13:02Like force, and mass,
and gravitational attraction? -
13:02 - 13:04Or is it observer-relative?
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13:04 - 13:08Well, some computations are intrinsic.
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13:08 - 13:10I add two plus two to get four,
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13:10 - 13:13that's going on no matter
what anybody thinks. -
13:13 - 13:17But when I hold out my pocket calculator
and do the calculation, -
13:17 - 13:19the only intrinsic phenomenon
-
13:19 - 13:22is the electronic circuit
and its behavior. -
13:22 - 13:24That's the only absolute phenomenon.
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13:24 - 13:26All the rest is interpreted by us.
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13:26 - 13:30Computation only exists
relative to consciousness. -
13:30 - 13:33Either a conscious agent
is carrying the computation -
13:33 - 13:34or it has a piece of machinery
-
13:34 - 13:37that admits
of a computational interpretation. -
13:37 - 13:39That doesn't mean
computation is arbitrary, -
13:39 - 13:42I spent a lot of money
on this hardware, -
13:42 - 13:44but we have this persistent confusion
-
13:44 - 13:46between objectivity and subjectivity
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13:46 - 13:48as features of reality,
-
13:48 - 13:50and objectivity and subjectivity
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13:50 - 13:53as features of claims.
-
13:53 - 13:56And the bottom line
of this part of my talk, is this: -
13:56 - 14:00you can have
a completely objective science, -
14:00 - 14:03a science where you make
objectively true claims -
14:03 - 14:05about a domain whose existence
is subjective, -
14:05 - 14:09whose existence is in the human brain,
-
14:09 - 14:13consisting of subjective states
or sensations, or feeling, or awareness. -
14:13 - 14:17So the objection, that you can't have
an objective science of consciousness -
14:17 - 14:21because it's subjective,
and science is objective, -
14:21 - 14:24that's a pun, that's a bad pun
on objectivity and subjectivity. -
14:24 - 14:29You can make objective claims
about a domain that is subjective -
14:29 - 14:31in its mode of existence,
-
14:31 - 14:34and indeed, that's what neurologists do.
-
14:34 - 14:37You have patients
that actually suffered pains -
14:37 - 14:40and you are trying to get
an objective science of that. -
14:40 - 14:42I promised to refute all these guys,
-
14:42 - 14:44but I don't have
an awful lot of time left, -
14:44 - 14:46but let me refute a couple more of them.
-
14:46 - 14:51I said that behaviorism ought to be
one of the great embarrassments -
14:51 - 14:52of our intellectual culture,
-
14:52 - 14:55because it's refuted the moment
you think about it. -
14:55 - 14:58Your mental states are identical
with your behavior? -
14:58 - 15:01Well, think about the distinction
between feeling a pain, -
15:01 - 15:03and engaging in pain behavior.
-
15:03 - 15:05I mean, I won't demonstrate pain behavior
-
15:05 - 15:07but I can tell you
I am not having any pains right now! -
15:07 - 15:09So it's an obvious mistake.
-
15:09 - 15:10Why did they make the mistake?
-
15:10 - 15:12The mistake was, and you go back
-
15:12 - 15:15and ready the literature on this,
you can see this over and over, -
15:15 - 15:18they think [that] if you accept
-
15:18 - 15:21the irreducible existence
of consciousness, -
15:21 - 15:23you're giving up on science,
-
15:23 - 15:25you're giving up on 300 years
-
15:25 - 15:28of human progress and human hope
and all the rest of it. -
15:28 - 15:31And the message
I want to leave you with is -
15:31 - 15:35consciousness has to become accepted
as a genuine biological phenomenon, -
15:35 - 15:39as much subject to scientific analysis
-
15:39 - 15:41as any other phenomena in biology,
or, for that matter, -
15:41 - 15:43the rest of science!
-
15:43 - 15:44Thank you very much.
-
15:44 - 15:45(Applause)
- Title:
- Consciousness and the brain | John Searle | TEDxCERN
- Description:
-
This talk was given at a local TEDx event, produced independently of the TED conferences.
John Searle, one of the world's great philosophers of mind and language, has spent fifty years stimulating thinking around the world. What he says about consciousness as a biological phenomenon will challenge you! - Video Language:
- English
- Team:
- closed TED
- Project:
- TEDxTalks
- Duration:
- 15:51
Denise RQ edited English subtitles for Consciousness and the brain| John Searle | TEDxCERN | ||
Denise RQ edited English subtitles for Consciousness and the brain| John Searle | TEDxCERN | ||
Denise RQ edited English subtitles for Consciousness and the brain| John Searle | TEDxCERN | ||
Denise RQ edited English subtitles for Consciousness and the brain| John Searle | TEDxCERN | ||
Denise RQ approved English subtitles for Consciousness and the brain| John Searle | TEDxCERN | ||
Denise RQ edited English subtitles for Consciousness and the brain| John Searle | TEDxCERN | ||
Denise RQ edited English subtitles for Consciousness and the brain| John Searle | TEDxCERN | ||
Denise RQ edited English subtitles for Consciousness and the brain| John Searle | TEDxCERN |