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

“When one tries to rise above Nature one is liable to fall below it. The highest type of man may revert to the animal if he leaves the straight road of destiny.”

“There are many men in London, you know, who, some from shyness, some from misanthropy, have no wish for the company of their fellows. Yet they are not averse to comfortable chairs and the latest periodicals. It is for the convenience of these that the Diogenes Club was started, and it now contains the most unsociable and unclubbable men in town. No member is permitted to take the least notice of any other one. Save in the Stranger's Room, no talking is, under any circumstances, allowed, and three offenses, if brought to the notice of the committee, render the talker liable to expulsion. My brother was one of the founders, and I have myself found it a very soothing atmosphere.”

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

“I said that he was my superior in observation and deduction. If the art of the detective began and ended in reasoning from an armchair, my brother would be the greatest criminal agent that ever lived. But he has no ambition and no energy. He will not even go out of his way to verify his own solutions, and would rather be considered wrong than take the trouble to prove himself right.”

“To the man who loves art for its own sake, it is frequently in its least important and lowliest manifestations that the keenest pleasure is to be derived.”

“..There is no treachery in the truth. There may be pain, but to face honestly all possible conclusions formed by a set of facts is the noblest route possible for a human being”