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.
We all learn by experience, and your lesson this time is that you should never lose sight of the alternative. Sherlock Holmes speaking with Dr. Watson.
What is the meaning of it, Watson? said Holmes solemnly as he laid down the paper. "What object is served by this circle of misery and violence and fear? It must tend to some end, or else our universe is ruled by chance, which is unthinkable. But what end? There is the great standing perennial problem to which human reason is as far from an answer as ever.
Detection is, or ought to be, an exact science and should be treated in the same cold and unemotional manner. You have attempted to tinge it with romanticism, which produces much the same effect as if you worked a love-story ... Some facts should be suppressed, or, at least, a just sense of proportion should be observed in treating them. The only point in the case which deserved mention was the curious analytical reasoning from effects to causes, by which I succeeded in unravelling it.'' —Sherlock Holmes on John Watson's "pamphlet", "A Study in Scarlet".
Let me run over the principal steps. We approached the case, you remember, with an absolutely blank mind, which is always an advantage. We had formed no theories. We were simply there to observe and to draw inferences from our observations.
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. [...] It is a mistake to think that that little room has elastic walls and can distend to any extent. [...] It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.
Several incidents in my life have convinced me of spiritual interposition - of the promptings of some beneficent force outside ourselves, which tries to help us where it can.
It's a very cheery thing to come into London by any of these lines which run high and allow you to look down upon the houses like this." I thought he was joking, for the view was sordid enough, but he soon explained himself. "Look at those big, isolated clumps of buildings rising up above the slates, like brick islands in a lead-coloured sea." "The board-schools." "Light-houses, my boy! Beacons of the future! Capsules with hundreds of bright little seeds in each, out of which will spring the wiser, better England of the future.