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, my friend, I am not drunk. I have just been to the dentist, and need not return for another six months! Is it not the most beautiful thought? --Poirot

If only-if only, Hastings, you would part your hair in the middle instead of at the side! What a difference it would make to the symmetry of your appearance. And your moustache. If you must have a moustache, let it be a real moustache-a thing of beauty such as mine.

... 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.

There is no detective in England equal to a spinster lady of uncertain age with plenty of time on her hands.

Downstairs in the lounge, by the third pillar from the left, there sits an old lady with a sweet, placid, spinsterish face and a mind that has plumbed the depths of human iniquity and taken it all as in the day's work....where crime is concerned, she's the goods.

I learned ... that one can never go back, that one should not ever try to go back - that the essence of life is going forward. Life is really a one way street, isn't it?