So we need to ignore the unimportant. More than that, it may be useful to destroy it from our memories.
Watson, describing Holmes in"A Study in Scarlet" says
His ignorance was as remarkable as his knowledge. Of con-
temporary 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 compo-
sition of the Solar System. That any civilized human being in
this nineteenth century should not be aware that the earth trav-
elled 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 ex-
pression 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, therefore, 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."
I was on the point of asking him what that work might be, but
something in his manner showed me that the question would be
an unwelcome one. I pondered over our short conversation
however, and endeavoured to draw my deductions from it. He
said that he would acquire no knowledge which did not bear
upon his object. Therefore all the knowledge which he possessed
was such as would be useful to him. I enumerated in my own
mind all the various points upon which he had shown me that he
was exceptionally well informed. I even took a pencil and jotted
them down. I could not help smiling at the document when I had
completed it. It ran in this way:
Sherlock Holmes -- his limits
1. Knowledge of Literature. -- Nil.
2. " " Philosophy. -- Nil.
3. " " Astronomy. -- Nil.
4. " " Politics. -- Feeble.
5. " " Botany. -- Variable.
Well up in belladonna, opium, and poisons generally.
Knows nothing of practical gardening.
6. Knowledge of Geology. -- Practical, but limited.
Tells at a glance different soils from each other.
After walks has shown me splashes upon his trou-
sers, and told me by their colour and consistence in
what part of London he had received them.
7. Knowledge of Chemistry. -- Profound.
8. " " Anatomy. -- Accurate, but unsystematic
9. " " Sensational Literature. -- Immense.
He appears to know every detail of every horror
perpetrated in the century.
10. Plays the violin well.
11. Is an expert singlestick player, boxer, and swordsman.
12. Has a good practical knowledge of British law.
Holmes later says,
"I gathered up some scattered ash from the floor. It was dark in colour and flaky -- such an ash is only made by a Trichinopoly. I have made a special study of cigar ashes -- in fact, I have written a monograph upon the subject. I flatter myself that I can distinguish at a glance the ash of any known brand either of cigar or of tobacco. It is just in such details that the skilled detective differs from the Gregson and Lestrade type."Pastor Whitaker's point, I think, was that we need the discipline of public worship to make us forget daily distractions and focus our minds on God. Or perhaps he was talking about confession, and the need to focus on our own imperfection-- the point is equally valid there.
I'm reminded too, of the story of "Shooting the Bird's Eye," pp. 18-19 of The Five Sons of King Pandu: The Story of the Mahabharata , adapted from the Kisari Ganguli translation by Elizabeth Seeger, New York: William R. Scott (1967). It is in my Readings in Games and Information.
And I am reminded of the cleverness of the Hindu pantheon, in having three major gods, Brahma the Creator, Vishnu the Preserver, and Shiva the Destroyer. The first two are principles whose importance comes easily to us. The Destroyer as an evil god comes easily too, but what is most interesting is the idea that The Destroyer is useful. To Create, one must Destroy first. We must eliminate the evil and useless from our minds.
This, too, is an idea in economics--Opportunity Cost. It is good to have people in textile factories lose their jobs, because if they do not leave those jobs, there will be nobody to take the better jobs in the software laboratories. This is Schumpeter's process of Creative Destruction, an integral part of innovation.
One final story along these lines. I might be wrong, but here's my recollection. For 100 years or more, the Eisenhower family were quiet small-scale farmers. Then Mr. Eisenhower lost his farm, in bad times. He had three sons who, forced off the land and unable to become small-time farmers, became a bank president, a university president, and President of the United States.
This is getting self-referential. Was I foolish to remember all these disparate facts? No, because they are not disparate after all, I discover. They are all important and connected. I didn't know that in advance, but I did know that each fact or idea was interesting in itself, and in my line of work, interesting things turn up useful later on.
[in full at 04.04.04a.htm ]
To return to Eric Rasmusen's weblog, click http://php.indiana.edu/~erasmuse/w/0.rasmusen.htm.