I could not rest, Watson, I could not sit quiet in my chair, if I thought that such a man as Professor Moriarty were walking the streets of London unchallenged.

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

I have taken to living by my wits.

It is a mistake to confound strangeness with mystery.

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.

‎A change of work is the best rest.

If my future were black, it was better surely to face it like a man than to attempt to brighten it by mere will-o’-the-wisps of the imagination.