“No one appreciates the very special genius of your conversation as the dog does.”

“There's something wrong in not appreciating one's own special abilities, my girl. Find your own limitations, yes, but don't limit yourself with false modesty.”

“Conversation enriches the understanding, but solitude is the school of genius.”

“Don't just read it; fight it! Ask your own question, look for your own examples, discover your own proofs. Is the hypothesis necessary? Is the converse true? What happens in the classical special case? What about the degenerate cases? Where does the proof use the hypothesis?”

“His conversation does not show the minute-hand, but he strikes the hour very correctly.”

“Conversations consist for the most part of things one does not say.”

“What a falsehood it is to say that genius and industry are incompatible! Does one work of genius exist that has not also been a work of labour?”

“Aside from a cold appreciation of my own genius I felt that I was a modest man.”

“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.”

“I discovered two very important facts that day - Number one: The springs will pull the hair out of your legs, and Number two: the dog doesn't like to jump.”