the detective's highest talent lay in the gentle art of seeking favours under the guise of conferring them!

People should be interested in books, not their authors.

Words are such uncertain things, they so often sound well but mean the opposite of what one thinks they do.

Intuition is like reading a word without having to spell it out. A child can't do that because it has had so little experience. A grown-up person knows the word because they've seen it often before.

It often seems to me that's all detective work is, wiping out your false starts and beginning again." Yes, it is very true, that. And it is just what some people will not do. They conceive a certain theory, and everything has to fit into that theory. If one little fact will not fit it, they throw it aside. But it is always the facts that will not fit in that are significant.

Plots come to me at such odd moments, when I am walking along the street, or examining a hat shop… suddenly a splendid idea comes into my head.

Money ... is always the great clue to what is happening in the world.