They say that genius is an infinite capacity for taking pains," he remarked with a smile. "It's a very bad definition, but it does apply to detective work.

Now is the dramatic moment of fate, Watson, when you hear a step upon the stair which is walking into your life, and you know not whether for good or ill.

He [Professor Moriarty] is the Napoleon of crime, Watson. He is the organizer of half that is evil and of nearly all that is undetected in this great city. He is a genius, a philosopher, an abstract thinker. He has a brain of the first order.

The husband was a teetotaller, there was no other woman, and the conduct complained of was that he had drifted into the habit of winding up every meal by taking out his false teeth and hurling them at his wife.

Heaven, too, was very near to them in those days. God's direct agency was to be seen in the thunder and the rainbow, the whirlwind and the lightning. To the believer, clouds of angels and confessors, and martyrs, armies of the sainted and the saved, were ever stooping over their struggling brethren upon earth, raising, encouraging, and supporting them.

That which is clearly known hath less terror than that which is but hinted at and guessed.

Dogs don't make mistakes.