I could not rest, Watson, I could not sit quiet in my chair, if I thought that such a man as Professor Moriarty were walking the streets of London unchallenged.

...it is only when a man goes out into the world with the thought that there are heroisms all round him, and with the desire all alive in his heart to follow any which may come within sight of him, that he breaks away... from the life he knows, and ventures forth into the wonderful mystic twilight land where lie the great adventures and the great rewards.

Some facts should be suppressed, or, at least, a just sense of proportion should be observed in treating them.

As a rule, said Holmes, the more bizarre a thing is the less mysterious it proves to be. It is your commonplace, featureless crimes which are really puzzling, just as a commonplace face is the most difficult to identify.

A fine thought in fine language is a most precious jewel, and should not be hid away, but be exposed for use and ornament.

The most winning woman I ever knew was hanged for poisoning three little children for their insurance-money, and the most repellent man of my acquaintance is a philanthropist who has spent nearly a quarter of a million upon the London poor.

If I had never touched Holmes, who has tended to obscure my higher work, my position in literature would at the present moment be a more commanding one.