His ignorance was as remarkable as his knowledge. Of contemporary literature, philosophy and politics he appeared to know next to nothing. Upon my quoting Thomas Carlyle, he inquired in the naivest way who he might be and what he had done. My surprise reached a climax, however, when I found incidentally that he was ignorant of the Copernican Theory and of the composition of the Solar System. That any civilized human being in this nineteenth century should not be aware that the earth travelled round the sun appeared to me to be such an extraordinary fact that I could hardly realize it.
“You appear to be astonished,” he said, smiling at my expression of surprise. “Now that I do know it I shall do my best to forget it.”
“To forget it!”
“You see,” he explained, “I consider that a man's brain originally is like a little empty attic, and you have to stock it with such furniture as you choose. A fool takes in all the lumber of every sort that he comes across, so that the knowledge which might be useful to him gets crowded out, or at best is jumbled up with a lot of other things, so that he has a difficulty in laying his hands upon it. Now the skilful workman is very careful indeed as to what he takes into his brain-attic. He will have nothing but the tools which may help him in doing his work, but of these he has a large assortment, and all in the most perfect order. It is a mistake to think that that little room has elastic walls and can distend to any extent. Depend upon it there comes a time when for every addition of knowledge you forget something that you knew before. It is of the highest importance, t
herefore, not to have useless facts elbowing out the useful ones.”
“But the Solar System!” I protested.
“What the deuce is it to me?” he interrupted impatiently: “you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work.”
Heはホームズ、Iはワトスン
ここの二人の会話好きです。
教養がある人物(ホームズ)が地動説も、地球が太陽の周りを公転していることも知らないのかと驚くドクターワトスン
今知ったこと(地動説とか)を忘れるようにしなきゃというホームズ
ホームズが考える頭脳についての言葉が思慮深いというかはっとしました
「僕が思うに、人間の頭脳というものは、もともと小さな空っぽの屋根裏部屋のようなもので、そこに自分が選んだ家具を入れとくべきなんだ。
ところが愚かなものは、手あたりしだいにいろんなガラクタまでしまいこむから、役にたつ肝心の知識はみんなはみだしてしまうか、はみださないまでも他の物とごちゃ混ぜになって、いざという時に取り出しにくくなってしまう。
熟練者は、脳という屋根裏部屋へはちゃんと細心の注意を払いながら知識をしまうんだ。自分の仕事に役立つ知識以外は、いっさい入れない。それだけでもたいへんな種類にのぼるから、あらゆる知識を完璧に整理しなくてはならない。
そもそも、この小さな部屋が伸縮自在の壁ででもできているかのように、いくらでも伸びたり広がったりすると考えるのが間違いなんだ。どんどんつめこんでいけば、新しいことをひとつ覚えるたびに古いことをひとつ忘れる時が、必ずやってくる。
だから役に立たない知識のために、有用な知識がおし出されないようにすることがきわめて大切なんだよ」