When I write down a thought, I set something in motion -- something with a mass and direction and inertia all of its own, something that often starts taking me where I don't want to go. Thoughts attract other thoughts -- some of them welcome, some unwelcome, more of them unrelated or irrelevant. Composition is the art of putting discipline on these thoughts, of choosing them and arranging them so that one snaps neatly onto the other, and all flow as one. The best writers can make this process look easy, and honest.