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  • I'm going to talk about consciousness.

    翻訳: Kazunori Akashi 校正: Emi Kamiya

  • Why consciousness?


  • Well, it's a curiously neglected subject,


  • both in our scientific and our philosophical culture.

    それは「意識」が 科学や哲学の世界で

  • Now why is that curious?

    奇妙と言っていい位 軽視されたテーマだからです

  • Well, it is the most important aspect of our lives


  • for a very simple, logical reason,

    意識は私達が生きる上で 最も重要なものだからです

  • namely, it's a necessary condition on anything


  • being important in our lives that we're conscious.

    意識は 生きる上で大切な

  • You care about science, philosophy, music, art, whatever --


  • it's no good if you're a zombie or in a coma, right?

    科学や哲学 音楽や 芸術などに関心があっても

  • So consciousness is number one.

    ゾンビや昏睡状態の人には 意味がありません

  • The second reason is that when people do


  • get interested in it, as I think they should,

    2つ目の理由は 人々が意識に ―

  • they tend to say the most appalling things.


  • And then, even when they're not saying appalling things

    おかしなことを 主張しがちだからです

  • and they're really trying to do serious research,

    たとえ そんなことは言わず

  • well, it's been slow. Progress has been slow.


  • When I first got interested in this, I thought, well,


  • it's a straightforward problem in biology.

    私が初めて関心を持ったとき 意識とは 紛れもなく

  • Let's get these brain stabbers to get busy and figure out


  • how it works in the brain.

    だから機械を使って 脳内部の機能を知ろうとしました

  • So I went over to UCSF and I talked to all

    だから機械を使って 脳内部の機能を知ろうとしました

  • the heavy-duty neurobiologists there,

    そこでカリフォルニア大学 サンフランシスコ校に行って

  • and they showed some impatience,


  • as scientists often do when you ask them embarrassing questions.


  • But the thing that struck me is, one guy said in exasperation,

    厄介な質問を受けた 科学者にはありがちなことです

  • a very famous neurobiologist, he said, "Look,

    中でも強く印象に残ったのは ある高名な神経生物学者が

  • in my discipline it's okay to be interested in consciousness,


  • but get tenure first. Get tenure first."

    「我々の分野では 意識に関心を持ってもいいが

  • Now I've been working on this for a long time.

    教授になって 終身在職権を得るのが先だ」

  • I think now you might actually get tenure

    私は長い間 このテーマに取り組んでいます

  • by working on consciousness.

    今なら意識の研究で 終身在職権を得られるかもしれません

  • If so, that's a real step forward.

    今なら意識の研究で 終身在職権を得られるかもしれません

  • Okay, now why then is this curious reluctance

    だとしたらこの分野も 進歩したものです

  • and curious hostility to consciousness?

    では なぜ意識の研究に 奇妙な抵抗感や敵意を持つのか?

  • Well, I think it's a combination of two features

    では なぜ意識の研究に 奇妙な抵抗感や敵意を持つのか?

  • of our intellectual culture


  • that like to think they're opposing each other


  • but in fact they share a common set of assumptions.


  • One feature is the tradition of religious dualism:


  • Consciousness is not a part of the physical world.

    一つ目の特徴は 宗教的な二元論の伝統です

  • It's a part of the spiritual world.

    つまり意識は物質世界に属さず ―

  • It belongs to the soul,


  • and the soul is not a part of the physical world.

    意識は魂に宿り 魂は物質世界に 属さないという考え方です

  • That's the tradition of God, the soul and immortality.

    意識は魂に宿り 魂は物質世界に 属さないという考え方です

  • There's another tradition that thinks it's opposed to this

    これが神の教え 魂と不死の伝統です

  • but accepts the worst assumption.

    一方 自らこれに 対立するとしながら ―

  • That tradition thinks that we are heavy-duty scientific materialists:

    最悪の前提は容認する 伝統があります

  • Consciousness is not a part of the physical world.


  • Either it doesn't exist at all, or it's something else,

    意識は物質世界に属さず そもそも存在しないか ―

  • a computer program or some damn fool thing,


  • but in any case it's not part of science.


  • And I used to get in an argument that really gave me a stomachache.

    どちらにせよ科学の 対象ではないという見方です

  • Here's how it went.

    よく胃が痛むような 議論になりました

  • Science is objective, consciousness is subjective,


  • therefore there cannot be a science of consciousness.

    「科学は客観的で 意識は主観的である ―

  • Okay, so these twin traditions are paralyzing us.

    したがって意識の科学は 存在しえない」

  • It's very hard to get out of these twin traditions.

    私達はこの2つの伝統に縛られ 身動きができません

  • And I have only one real message in this lecture,

    2つの伝統から逃れるのは とても難しいことです

  • and that is, consciousness is a biological phenomenon

    今回 本当に伝えたい事は ただひとつ ―

  • like photosynthesis, digestion, mitosis --

    意識が生物学的な 現象だということです

  • you know all the biological phenomena -- and once you accept that,

    光合成や消化や 細胞分裂と同じです

  • most, though not all, of the hard problems

    これらの生物学的現象を みなさんもご存じでしょう

  • about consciousness simply evaporate.

    こう考えれば 意識に関する厄介な問題は

  • And I'm going to go through some of them.

    全てではないにせよ ほとんど解消します

  • Okay, now I promised you to tell you some

    そんな問題を いくつか見ていきます

  • of the outrageous things said about consciousness.

    さて 意識に関するおかしな主張を

  • One: Consciousness does not exist.


  • It's an illusion, like sunsets.


  • Science has shown sunsets and rainbows are illusions.


  • So consciousness is an illusion.

    科学的に言えば 夕日も虹も錯覚だ

  • Two: Well, maybe it exists, but it's really something else.


  • It's a computer program running in the brain.

    2「意識は在るかもしれないが 何か別のものである ―

  • Three: No, the only thing that exists is really behavior.

    意識は脳の中で動く コンピュータ・プログラムだ」

  • It's embarrassing how influential behaviorism was,


  • but I'll get back to that.

    行動主義のかつての影響力を思うと 恥ずかしくなりますが

  • And four: Maybe consciousness exists,


  • but it can't make any difference to the world.


  • How could spirituality move anything?


  • Now, whenever somebody tells me that, I think,

    「心的なものが 何か動かせるとでも?」

  • you want to see spirituality move something?

    誰かがこう言うたびに 「見せようか?」と聞きたくなります

  • Watch. I decide consciously to raise my arm,

    誰かがこう言うたびに 「見せようか?」と聞きたくなります

  • and the damn thing goes up. (Laughter)

    見てください 私が意識的に手を上げようとすれば

  • Furthermore, notice this:

    こいつは上がるんです (笑)

  • We do not say, "Well, it's a bit like the weather in Geneva.


  • Some days it goes up and some days it doesn't go up."

    私達はこうは言いません 「腕はジュネーブの天気みたいだ ―

  • No. It goes up whenever I damn well want it to.

    上がる日もあれば 上がらない日もある」

  • Okay. I'm going to tell you how that's possible.

    そうではなく 上げたい時には 上がるのです

  • Now, I haven't yet given you a definition.


  • You can't do this if you don't give a definition.

    ああ 定義がまだでしたね

  • People always say consciousness is very hard to define.


  • I think it's rather easy to define

    意識の定義は 難しいと言われます

  • if you're not trying to give a scientific definition.


  • We're not ready for a scientific definition,


  • but here's a common-sense definition.

    科学的な定義は まだできませんが

  • Consciousness consists of all those states of feeling

    常識的な定義なら こうです

  • or sentience or awareness.

    意識とは 感情 感覚 認識の あらゆる状態から成るものです

  • It begins in the morning when you wake up from a dreamless sleep,

    意識とは 感情 感覚 認識の あらゆる状態から成るものです

  • and it goes on all day until you fall asleep

    意識は 夢を見なかった場合 朝 目覚めた時に始まり ―

  • or die or otherwise become unconscious.


  • Dreams are a form of consciousness on this definition.

    終わるのは 眠るか 死ぬか 意識がなくなる時です

  • Now, that's the common-sense definition. That's our target.

    夢は この定義では 意識の一種です

  • If you're not talking about that, you're not talking about consciousness.

    これが常識的定義です 検討するのは この定義です

  • But they think, "Well, if that's it, that's an awful problem.

    当てはまらないものは 意識ではないと考えます

  • How can such a thing exist as part of the real world?"

    こう考える人もいるでしょう 「仮にその通りだとしても ―

  • And this, if you've ever had a philosophy course,

    そんなものがどうやって 現実世界に存在できるのか?」

  • this is known as the famous mind-body problem.

    哲学を学んだ方なら ご存じでしょう

  • I think that has a simple solution too. I'm going to give it to you.

    これが かの有名な心身問題です

  • And here it is: All of our conscious states, without exception,

    この問題の単純な 解決策はこうです

  • are caused by lower-level neurobiological processes in the brain,

    私達の意識状態は 例外なくすべて ―

  • and they are realized in the brain

    脳の低次の神経生物学的 プロセスから生じ

  • as higher-level or system features.

    より高次の機能 または ―

  • It's about as mysterious as the liquidity of water.


  • Right? The liquidity is not an extra juice squirted out

    意識にまつわる謎は 水の流動性に似ています

  • by the H2O molecules.

    そうでしょう? 流動性は水分子が液体を ―

  • It's a condition that the system is in.


  • And just as the jar full of water can go from liquid to solid


  • depending on the behavior of the molecules,

    ちょうど容器いっぱいの水が 分子の挙動に従って

  • so your brain can go from a state of being conscious


  • to a state of being unconscious,


  • depending on the behavior of the molecules.

    意識がある状態から 無意識の状態へと変化します

  • The famous mind-body problem is that simple.

    意識がある状態から 無意識の状態へと変化します

  • All right? But now we get into some harder questions.

    有名な心身問題も こんなに単純なのです

  • Let's specify the exact features of consciousness,

    次に もっと難しい問題に 取りかかりましょう

  • so that we can then answer those four objections

    意識の様々な特徴 そのものを特定することで

  • that I made to it.

    先ほどあげた4つの意見に 反論していきましょう

  • Well, the first feature is, it's real and irreducible.

    先ほどあげた4つの意見に 反論していきましょう

  • You can't get rid of it.

    意識の第一の特徴は 実在していて 他のものに還元できない点です

  • You see, the distinction between reality and illusion


  • is the distinction between how things


  • consciously seem to us and how they really are.


  • It consciously seems like there's --


  • I like the French "arc-en-ciel" —

    フランス語で "arc-en-ciel"(虹) と言うように 意識の中では

  • it seems like there's an arch in the sky,

    フランス語で "arc-en-ciel"(虹) と言うように 意識の中では

  • or it seems like the sun is setting over the mountains.

    虹は 空にかかるアーチのように見え

  • It consciously seems to us, but that's not really happening.

    太陽は 山の向こうに 沈んでいくように見えます

  • But for that distinction between

    意識の中では そう見えても 実際に起きている事とは違います

  • how things consciously seem and how they really are,


  • you can't make that distinction for the very existence of consciousness,


  • because where the very existence of consciousness is concerned,

    同様の区別を意識の存在に対して 当てはめることはできません

  • if it consciously seems to you that you are conscious,

    なぜなら意識の存在自体を 問題にする場合 ―

  • you are conscious.


  • I mean, if a bunch of experts come to me and say,


  • "We are heavy-duty neurobiologists and we've done a study

    専門家が次々にやってきて 私にこう言ったとします

  • of you, Searle, and we're convinced you are not conscious,


  • you are a very cleverly constructed robot,"

    研究の結果 君には 意識がないという結論に至った

  • I don't think, "Well, maybe these guys are right, you know?"


  • I don't think that for a moment, because, I mean,

    でも「そうかも知れない」 などとは考えません

  • Descartes may have made a lot of mistakes, but he was right about this.

    そんなことを 少しも考えないのは

  • You cannot doubt the existence of your own consciousness.

    この件に限っては デカルトが正しく ―

  • Okay, that's the first feature of consciousness.

    自分の意識の存在は 自分では疑えないからです

  • It's real and irreducible.


  • You cannot get rid of it by showing that it's an illusion


  • in a way that you can with other standard illusions.

    意識は錯覚であると 指摘したところで

  • Okay, the second feature is this one

    普通の錯覚のように 無視することはできません

  • that has been such a source of trouble to us,


  • and that is, all of our conscious states

    私達にとって厄介な 問題の種になっています

  • have this qualitative character to them.


  • There's something that it feels like to drink beer

    それぞれ固有の質感を 備えているという点です

  • which is not what it feels like to do your income tax


  • or listen to music, and this qualitative feel


  • automatically generates a third feature,

    音楽を聴くときの感覚とは 違った何かがあります

  • namely, conscious states are by definition subjective


  • in the sense that they only exist as experienced

    すなわち意識状態とは 人間や動物といった主体 ―

  • by some human or animal subject,

    つまり意識状態を経験する 何らかの自己の

  • some self that experiences them.


  • Maybe we'll be able to build a conscious machine.

    当然 主観的なものです

  • Since we don't know how our brains do it,

    意識を持つ機械が できる可能性はあっても

  • we're not in a position, so far, to build a conscious machine.

    人間の脳が意識を持つ 仕組みが不明なので

  • Okay. Another feature of consciousness

    今のところ そんな機械を 作れる状況ではありません

  • is that it comes in unified conscious fields.


  • So I don't just have the sight of the people in front of me

    統合された意識の場として 現れることです

  • and the sound of my voice and the weight of my shoes

    私は単に 目の前にいる人々の映像と

  • against the floor, but they occur to me

    自分の声と 床を踏む自分の靴の重さとを

  • as part of one single great conscious field


  • that stretches forward and backward.

    これらの知覚は前後に広がる 1つの大きな意識の場の

  • That is the key to understanding


  • the enormous power of consciousness.


  • And we have not been able to do that in a robot.


  • The disappointment of robotics derives from the fact

    まだロボットで 実現するのは不可能なことです

  • that we don't know how to make a conscious robot,

    残念ながら ロボット工学の分野で

  • so we don't have a machine that can do this kind of thing.

    意識を与える方法が 発見されるまで

  • Okay, the next feature of consciousness,

    意識の場を持つ機械は 手に入らないのです

  • after this marvelous unified conscious field,

    この統合した意識の場という ―

  • is that it functions causally in our behavior.

    すごい特徴に続くのは 意識が 私達の行動の

  • I gave you a scientific demonstration by raising my hand,


  • but how is that possible?

    先ほど私は手を上げることで 科学的に示しましたが

  • How can it be that this thought in my brain


  • can move material objects?

    脳の中で考えたことが どういう仕組みで

  • Well, I'll tell you the answer.


  • I mean, we don't know the detailed answer,


  • but we know the basic part of the answer, and that is,


  • there is a sequence of neuron firings,


  • and they terminate where the acetylcholine


  • is secreted at the axon end-plates of the motor neurons.

    運動ニューロンの軸索末端に 信号が到達すると

  • Sorry to use philosophical terminology here,


  • but when it's secreted at the axon end-plates of the motor neurons,


  • a whole lot of wonderful things happen in the ion channels

    運動ニューロンの軸索末端で アセチルコリンが分泌されると

  • and the damned arm goes up.

    イオンチャンネルで すごいことが次々起こって

  • Now, think of what I told you.


  • One and the same event,

    ここまでの話を 考えてみてください

  • my conscious decision to raise my arm


  • has a level of description where it has all of these


  • touchy-feely spiritual qualities.

    別のレベルでは 感覚的で心的な性質があると

  • It's a thought in my brain, but at the same time,


  • it's busy secreting acetylcholine

    意識的な決定とは 脳内の思考であると同時に

  • and doing all sorts of other things

    アセチルコリンを せっせと分泌することや

  • as it makes its way from the motor cortex


  • down through the nerve fibers in the arm.

    腕の神経線維までの間に生じる ―

  • Now, what that tells us is that our traditional vocabularies

    その他の様々な 現象でもあるのです

  • for discussing these issues are totally obsolete.

    ここからわかるのは 私達が意識の問題を

  • One and the same event has a level of description

    語る時の表現は 時代遅れだということです

  • where it's neurobiological, and another level of description

    同一の事象を 神経生物学的にも

  • where it's mental, and that's a single event,

    心的にも説明できますが それでも事象は一つです

  • and that's how nature works. That's how it's possible


  • for consciousness to function causally.


  • Okay, now with that in mind,


  • with going through these various features of consciousness,


  • let's go back and answer some of those early objections.


  • Well, the first one I said was, consciousness doesn't exist,

    先ほどの反論の いくつかに答えていきましょう

  • it's an illusion. Well, I've already answered that.

    最初の反論は 「意識は錯覚で存在しない」です

  • I don't think we need to worry about that.

    これにはもう答えたので 気にしなくていいでしょう

  • But the second one had an incredible influence,

    これにはもう答えたので 気にしなくていいでしょう

  • and may still be around, and that is,

    2つ目は驚くほど影響力があって 今でも耳にするかも知れません

  • "Well, if consciousness exists, it's really something else.

    2つ目は驚くほど影響力があって 今でも耳にするかも知れません

  • It's really a digital computer program running in your brain

    「意識が存在するとしても 本当は何か別のものである

  • and that's what we need to do to create consciousness

    それは脳の中で動く コンピュータ・プログラムで

  • is get the right program.

    意識を作るには 適切なプログラムを手に入れればいい

  • Yeah, forget about the hardware. Any hardware will do

    意識を作るには 適切なプログラムを手に入れればいい

  • provided it's rich enough and stable enough to carry the program."

    ハードウェアは気にするな プログラムを持てる位 ―

  • Now, we know that that's wrong.

    豊かで 安定していれば どんなものでもいい」

  • I mean, anybody who's thought about computers at all

    これが誤りなのは はっきりしています

  • can see that that's wrong, because computation

    コンピュータについて 少しでも考えたことがある人なら

  • is defined as symbol manipulation,


  • usually thought of as zeros as ones, but any symbols will do.

    情報処理の定義は 記号を操作することだからです

  • You get an algorithm that you can program

    普通は0 と 1 ですが どんな記号でも使えます

  • in a binary code, and that's the defining trait

    あるアルゴリズムを 2進コードでプログラムできることが

  • of the computer