When you have eliminated the impossible, what is left, no matter how unlikely, is the truth.

You say that your fare told you that he was a detective?" "Yes, he did." "When did he say this?" "When he left me." "Did he say anything more?" "He mentioned his name." Holmes cast a swift glance of triumph at me. "Oh, he mentioned his name, did he? That was imprudent. What was the name that he mentioned?" “His name," said the cabman, "was Mr. Sherlock Holmes.

The ideal reasoner, he remarked, would, when he had once been shown a single fact in all its bearings, deduce from it not only all the chain of events which led up to it but also all the results which would follow from it.

You see, but you do not observe.

To all the world he was the man of violence, half animal and half demon; but to her he always remained the little wilful boy of her own girlhood, the child who had clung to her hand. Evil indeed is the man who has not one woman to mourn him.

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

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.