“Mediocrity knows nothing higher than itself; but talent instantly recognizes genius.”

“You mentioned your name as if I should recognize it, but beyond the obvious facts that you are a bachelor, a solicitor, a freemason, and an asthmatic, I know nothing whatever about you.”

“It is stupidity rather than courage to refuse to recognize danger when it is close upon you.”

“There is nothing more deceptive than an obvious fact.”

“There is nothing more stimulating than a case where everything goes against you.”

“It is only when you touch the higher that you realize how low we may be among the possibilities of creation.”

“They say that genius is an infinite capacity for taking pains," he remarked with a smile. "It's a very bad definition, but it does apply to detective work.”