“What they need is a little immorality in their lives. Then they wouldn't be so busy looking for it in other people's.”

“No, I wouldn't. I wouldn’t tell a soul.''People who use that phrase are always the last to live up to it.”

“Your not reliable. You wouldn't be at all a comfortable sort of person to live with.”

“There is too much tendency to attribute to God the evils that man does of his own free will. I must concede you the Devil. God doesn't really need to punish us, Miss Barton. We're so busy punishing ourselves.”

“How little you might know of a person after living in the same house with them!”

“Excuse me, Monsieur Poirot. If you'd like to ask any questions, I'm sure the doctor wouldn't mind.Of course not. Of course not. Great admirer of yours, Monsieur Poirot. Little gray cells -- order and method. I know all about it.”

“Life can be very terrible," he said. "One needs much courage.""To kill oneself? yes, I suppose one does.""Also to live," said Poirot, "one needs courage.”