What can we know? What are we all? Poor silly half-brained things peering out at the infinite, with the aspirations of angels and the instinct of beasts.

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

There are times, young fellah, when every one of us must make a stand for human right and justice, or you never feel clean again.

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

The man might have died in a fit; but then the jewels are missing," mused the Inspector, "Ha! I have a theory. These flashes come upon me at times... What do you think of this, Holmes? Sholto was, on his own confession, with his brother last night. The brother died in a fit, on which Sholto walked off the treasure! How's that?" "On which the dead man very considerately got up and locked the door on the inside," said Holmes.

There is nothing more stimulating than a case where everything goes against you.

So swift, silent and furtive were his movements like those of a trained bloodhound picking out a scent, that I could not but think what a terrible criminal he would have made had he turned his energy and sagacity against the law instead of exerting them in its defense. -Dr. Watson, The Sign of the Four