There are many things that are unbelievable. Especially before breakfast, is it not? That is what one of your classics says. Six impossible things before breakfast.

It is completely unimportant. That is why it is so interesting.

... the belief in a superstratum of human beings ... is the most evil of all beliefs. For when you say, 'I am not as other men' -- you have lost the two most valuable qualities we have ever tried to attain: -- humility and brotherhood.

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.

They tried to be too clever---and that was their undoing.

Doctors can do almost anything nowadays, can't they, unless they kill you while they're trying to cure you.

An archaeologist is the best husband a woman can have. The older she gets the more interested he is in her.