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.

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.

What can we know? What are we all? Poor silly half-brained things peering out at the infinite, with the aspirations of angels and the instinct of beasts.

So swift, silent and furtive were his movements like those of a trained bloodhound picking out a scent, that I could not but think what a terrible criminal he would have made had he turned his energy and sagacity against the law instead of exerting them in its defense. -Dr. Watson, The Sign of the Four

As I turned away, I saw Holmes, with his back against a rock and his arms folded, gazing down at the rush of the waters. It was the last that I was ever destined to see of him in this world. - Watson.

The world is full of obvious things which nobody by any chance ever observes.

Just as an octopus may have his den in some ocean cave, and come floating out a silent image of horror to attack a swimmer, so I picture such a spirit lurking in the dark of the house which he curses by his presence, and ready to float out upon all whom he can injure.