“My business is that of every other good citizen - to uphold the law.”

“I am not the law, but I represent justice so far as my feeble powers go.”

“Holmes took up the stone and held it against the light. "It's a bonny thing," said he. "Just see how it glints and sparkles. Of course it is a nucleus and focus of crime. Every good stone is. They are the devil's pet baits. In the larger and older jewels every facet may stand for a bloody deed. This stone is not yet twenty years old. It was found in the banks of the Amoy River in soutern China and is remarkable in having every characteristic of the carbuncle, save that it is blue in shade instead of ruby red. In spite of its youth, it has already a sinister history. There have been two murders, a vitriol-throwing, a suicide, and several robberies brought about for the sake of this forty-grain weight of crystallised charcoal. Who would think that so pretty a toy would be a purveyor to the gallows and the prison?”

“There is nothing in which deduction is so necessary as in religion," said he, leaning with his back against the shutters. "It can be built up as an exact science by the reasoner. Our highest assurance of the goodness of Providence seems to me to rest in the flowers. All other things, our powers, our desires, our food, are all really necessary for our existence in the first instance. But this rose is an extra. Its smell and its colour are an embellishment of life, not a condition of it. It is only goodness which gives extras, and so I say again that we have much to hope from the flowers.”

“That any civilized human being in this nineteenth century should not be aware that the earth traveled 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 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 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 most perfect order. It is a mistake to think that 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.”

“If you want to write good copy, you must be where the things are.”

“My name is Sherlock Holmes. It is my business to know what other people do not know.”