You have a grand gift for silence, Watson. It makes you quite invaluable as a companion.

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. [...] It is a mistake to think that that little room has elastic walls and can distend to any extent. [...] It is of the highest importance, therefore, not to have useless facts elbowing out the useful ones.

I think there are certain crimes which the law cannot touch, and which therefore, to some extent, justify private revenge.

The devil’s agents may be of flesh and blood, may they not?

I am not the law, but I represent justice so far as my feeble powers go.

Detection is, or ought to be, an exact science, and should be treated in the same cold and unemotional manner. You have attempted to tinge it with romanticism, which produces much the same effect as if you worked a love-story or an elopement into the fifth proposition of Euclid.

He seems to have declared war on the King’s English as well as on the English king.