There are two kinds of truth; The truth that lights the way and the truth that warms the heart. The fist of these is science and the second is art.

A writer who is afraid to overreach himself is as useless as a general who is afraid to be wrong.

Not only is the motion picture an art, but it is the one entirely new art that has been evolved on this planet for hundreds of years. It is the only art at which we of this generation have any possible chance to greatly excel.

The test of a writer is whether you want to read him again years after he should by the rules be dated.

I said something which gave you to think I hated cats. But gad, sir, I am one of the most fanatical cat lovers in the business. If you hate them, I may learn to hate you. If your allergies hate them, I will tolerate the situation to the best of my ability.

Love interest nearly always weakens a mystery because it introduces a type of suspense that is antagonistic to the detective's struggle to solve the problem. It stacks the cards, and in nine cases out of ten, it eliminates at least two useful suspects. The only effective love interest is that which creates a personal hazard for the detective - but which, at the same time, you instinctively feel to be a mere episode. A really good detective never gets married.

I have made three rules of writing for myself that are absolutes: Never take advice. Never show or discuss work in progress. Never answer a critic.