"The principle I always go on in writing a novel is to think of the characters in terms of actors in a play. I say to myself, if a big name were playing this part, and if he found that after a strong first act he had practically nothing to do in the second act, he would walk out. Now, then, can I twist the story so as to give him plenty to do all the way through? I believe the only way a writer can keep himself up to the mark is by examining each story quite coldly before he starts writing it and asking himself it is all right . I mean, once you go saying to yourself, "This is a pretty weak plot as it stands, but if I'm such a hell of a writer that my magic touch will make it okay," you're sunk. If they aren't in interesting situations, characters can't be major characters, not even if you have the rest of the troop talk their heads off about them."