It is a pity he did not write in pencil. As you have no doubt frequently observed, the impression usually goes through -- a fact which has dissolved many a happy marriage.

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

The weak man becomes strong when he has nothing, for then only can he feel the wild, mad thrill of despair.

Perhaps, when a man has special knowledge and special powers like my own, it rather encourages him to seek a complex explanation when a simpler one is at hand.

Really, Watson, you excel yourself," said Holmes, pushing back his chair and lighting a cigarette. "I am bound to say that in all the accounts which you have been so good as to give of my own small achievements you have habitually underrated your own abilities. It may be that you are not yourself luminous, but you are a conductor of light. Some people without possessing genius have a remarkable power of stimulating it. I confess, my dear fellow, that I am very much in your debt.

By a man's finger-nails, by his coat-sleeve, by his boots, by his trouser-knees, by the callosities of his forefinger and thumb, by his expression, by his shirt-cuff — By each of these things a man's calling is plainly revealed. That all united should fail to enlighten the competent inquirer in any case is almost inconceivable. You know that a conjurer gets no credit when once he has explained his trick; and if I show you too much of my method of working, you will come to the conclusion that I am a very ordinary individual after all.

It’s every man’s business to see justice done.