Life, my dear Watson, is infinitely stranger than fiction; stranger than anything which the mind of man could invent. We could not conceive the things that are merely commonplace to existence. If we could hover over this great city, remove the roofs, and peep in at the things going on, it would make all fiction, with its conventionalities and foreseen conclusions flat, stale and unprofitable.

It is the small men and not the great who hold their noses in the air.

You cannot see the lettuce and the dressing without suspecting a salad.

Philosophy, astronomy, and politics were marked at zero, I remember. Botany variable, geology profound as regards the mud stains from any region within fifty miles of town, chemistry eccentric, anatomy unsystematic, sensational literature and crime records unique, violin player, boxer, swordsman, lawyer, and self-poisoner by cocaine and tobacco.

The chief proof of man's real greatness lies in his perception of his own smallness.

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 most difficult crime to track is the one which is purposeless.