Ah! my dear Watson, there we come into those realms of conjecture, where the most logical mind may be at fault. Sherlock Holmes speaking with Dr. Watson.

Before turning to those moral and mental aspects of the matter which present the greatest difficulties, let the inquirer begin by mastering more elementary problems.

It's a wicked world, and when a clever man turns his brain to crime it is the worst of all.

It seems to leave the darkness rather blacker than before.

Education never ends, Watson. It is a series of lessons, with the greatest for the last.

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.

I have heard, Mr. Holmes, that you can see deeply into the manifold wickedness of the human heart.