The out-of-date returns in due course as the picturesque.

The human mind prefers to be spoon-fed with the thoughts of others, but deprived of such nourishment it will, reluctantly, begin to think for itself - and such thinking, remember, is original thinking and may have valuable results.

Every man should have aunts. They illustrate the triumph of guess work over logic.

Curious things, habits. People themselves never knew they had them. [Witness for the Prosecution, also published in The Hound of Death and Other Stories.]

Any coincidencce is worth noticing. You can throw it away later if it is only a coincidence.

Once I went professionally to an archaeological expedition-and I learnt something there. In the course of an excavation, when something comes up out of the ground, everything is cleared away very carefully all around it. You take away the loose earth, and you scrape here and there with a knife until finally your object is there, all alone, ready to be drawn and photographed with no extraneous matter confusing it. That is what I have been seeking to do-clear away the extraneous matter so that we can see the truth-the naked shining truth.

Sometimes I feel sure he is as mad as a hatter and then, just as he is at his maddest, I find there is a method in his madness.