It is of the highest importance in the art of detection to be able to recognise out of a number of facts which are incidental and which are vital.

Crime is common. Logic is rare. Therefore it is upon the logic rather than upon the crime that you should dwell.

It's a very cheery thing to come into London by any of these lines which run high and allow you to look down upon the houses like this." I thought he was joking, for the view was sordid enough, but he soon explained himself. "Look at those big, isolated clumps of buildings rising up above the slates, like brick islands in a lead-coloured sea." "The board-schools." "Light-houses, my boy! Beacons of the future! Capsules with hundreds of bright little seeds in each, out of which will spring the wiser, better England of the future.

Art in the blood is liable to take the strangest forms.

Nothing clears up a case so much as stating it to another person.

Of all ruins, that of a noble mind is the most deplorable.

Critics kind never mind! Critics flatter no matter! Critics blame all the same! Do your best damn the rest!