The mystery story is two stories in one: the story of what happened and the story of what appeared to happen.

Great loves were almost always great tragedies. Perhaps it was because love was never truly great until the element of sacrifice entered into it.

my crime books are actually novels and are written as such. One might even say that each one is really two novels, one of which is the story I tell the reader, and the other the buried story I know and let slip now and then into a clue to whet the reader's interest.

From class consciousness to class hatred was but a step.

Patience and endurance were not virtues in a woman; they were necessities, forced on her. Perhaps some day things would change and women would renounce them. They would rise up and say: 'We are not patient. We will endure no more.' Then what would happen to the world?

It is only in his head that man is heroic; in the pit of his stomach he is always a coward.

People that trust themselves a dozen miles from the city, in strange houses, with servants they don't know, needn't be surprised if they wake up some morning and find their throats cut.