No innocent person ever has an alibi.

I know there's a proverb which that says 'To err is human,' but a human error is nothing to what a computer can do if it tries.

The young people think the old people are fools-but the old people know the young people are fools.

Madame, the most kind, the most amiable are not always the cleverest.

Oh, my dear friend, it is impossible not to give oneself away - unless one never opens one's mouth! Speech is the deadliest of revealers.

He has neither what I call the outward vision (seeing details all around you what is called an observant person) nor the inner vision--concentration, the focusing of the mind on one object. He has a purposefully limited vision. He sees only what blends and harmonises with the bent of his mind.

There comes to everyone a turning point in their lives, M. Poirot. They stand at the crossroads and have to decide. My profession interests me enormously; it is a sorrow - a very great sorrow - to abandon it. But there are other claims. There is, M. Poirot, the happiness of a human being.