I always think loyalty's such a tiresome virtue.

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

The amount of missing girls I've had to trace and their family and their friends always say the same thing. 'She was a bright and affectionate disposition and had no men friends'. That's never true. It's unnatural. Girls ought to have men friends. If not, then there's something wrong about them.

Who are you? You don't belong to the police?' 'I am better than the police,' said Poirot. He said it without conscious arrogance. It was, to him, a simple statement of fact.

I can't imagine why everybody is always so keen for authors to talk about writing. I should have thought it was an author's business to write, not talk.

Youth is a failing only too easily outgrown.

Self-preservation's a man's first duty. And natives don't mind dying, you know. They don't feel about it as Europeans do.