the instinct to discard.
Courtesy of rodcorp.typepad.com, an excerpt from the 1993 Paris Review interview with Don DeLillo. It's so nice to see this online (thanks, Bryan, for the pointer); I have a copy of the issue in a box somewhere. This graf about his editing process has stuck with me for years...
Discarded pages mark the physical dimensions of a writer's labor--you know, how many shots it took to get a certain paragraph right. Or the awesome accumulation, the gross tonnage, of first draft pages. ... I find I'm more ready to discard pages than I used to be. I used to look for things to keep. I used to find ways to save a paragraph of sentence, maybe by relocating it. Now I look for ways to discard things. If I discard a sentence I like, it's almost as satisfying as keeping a sentence I like. I don't think I've become ruthless or perverse--just a bit more willing to believe that nature will restore itself. The instinct to discard is finally a kind of faith. It tells me there's a better way to do this page even though the evidence is not accessible at the present time.