“I never can stand seeing people pleased with themselves,” said Joanna. “It arouses all my worst instincts.”

“The point is that one's got an instinct to live. One does not live because one's reason assents to living. People who, as we say, 'would be better dead,' don’t want to die! People who apparently have got everything to live for just let themselves fade out of life because they have not got the energy to fight.”

“I was such a foolish girl - girls are foolish, Mr. Satterthwaite. They are so sure of themselves, so convinced they know best. People write and talk a lot of a ‘woman’s instinct.’ I don’t believe, Mr.Satterthwaite, that there is any such thing. There doesn’t seem to be anything that warns girls against a certain type of man. Nothing in themselves, I mean. Their parents warn them, but that’s no good - one doesn’t believe. It seems dreadful to say so, but there is something attractive to a girl in being told anyone is a bad man. She thinks at once that her love will reform him.”

“Curious things, habits. People themselves never knew they had them. [Witness for the Prosecution, also published in The Hound of Death and Other Stories.]”

“Instinct is a marvelous thing. It can neither be explained nor ignored.”

“Why shouldn't I hate her? She did the worst thing to me that anyone can do to anyone else. Let them believe that they're loved and wanted and then show them that it's all a sham.”

“As you yourself have said, what other explanation can there be?'Poirot stared straight ahead of him. 'That is what I ask myself,' he said. 'That is what I never cease to ask myself.”