Mediocrity knows nothing higher than itself, but talent instantly recognizes genius.

To let the brain work without sufficient material is like racing an engine. It racks itself to pieces.

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.

I feel that there is reason lurking in you somewhere, so we will patiently grope round for it.

He foresaw that she would be very much more useful to him in the character of a free woman.

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.

I had neither kith nor kin in England, and was therefore as free as air -- or as free as an income of eleven shillings and sixpence a day will permit a man to be. Under such circumstances, I naturally gravitated to London, that great cesspool into which all the loungers and idlers of the Empire are irresistibly drained.