What one man can invent, another can discover.

Once or twice in my career I feel that I have done more real harm by my discovery of the criminal than ever he had done by his crime. I have learned caution now, and I had rather play tricks with the law of England than with my own conscience.

if i could be assured of your destruction, i would in the interest of the public, cheerfully accept my death.

Violence is sometimes a duty.

Of all ghosts the ghosts of our old loves are the worst.

[Sherlock Holmes:] The temptation to form premature theories upon insufficient data is the bane of our profession.

I can never bring you to realize the importance of sleeves, the suggestiveness of thumb-nails, or the great issues that may hang from a boot-lace.