Ex-Professor Moriarty of mathematical celebrity... is the Napoleon of crime, Watson.

When we think how narrow and devious this path of nature is, how dimly we can trace it, for all our lamps of science, and how from the darkness which girds it round great and terrible possibilities loom ever shadowly upwards, it is a bold and a confident man who will put a limit to the strange by-oaths into which the human spirit may wander.

What is the meaning of it, Watson? said Holmes solemnly as he laid down the paper. "What object is served by this circle of misery and violence and fear? It must tend to some end, or else our universe is ruled by chance, which is unthinkable. But what end? There is the great standing perennial problem to which human reason is as far from an answer as ever.

It may be that you are not yourself luminous, but that you are a conductor of light. Some people without possessing genius have a remarkable power of stimulating it.

There's an east wind coming all the same, such a wind as never blew on England yet. It will be cold and bitter, Watson, and a good many of us may wither before its blast. But it's God's own wind none the less and a cleaner, better stronger land will lie in the sunshine when the storm has cleared.

I have wrought my simple plan If I give one hour of joy To the boy who’s half a man, Or the man who’s half a boy.

A study of family portraits is enough to convert a man to the theory of reincarnation.