"My mind rebels at stagnation. Give me problems, give me work, give me the most abstruse cryptogram, or the most intricate analysis, and I am in my own proper atmosphere. But I abhor the dull routine o…"

"The easiest way to make a man a fool is to give him an opinion and then contradict it."

"A man always finds it hard to realize that he may have finally lost a woman's love, however badly he may have treated her."

"The working classes need guidance, not revolution."

"I have a trade of my own. I suppose I am the only one in the world. I’m a consulting detective, if you can understand what that is."