From Bill Walsh, of course, in this recent article about copy editing:
"A lot of the time, the drawing-out-sources-and-ferreting-out-facts gene and the tighten-it-and-polish-it-up gene aren't contained in the same person. But the job I do is important, for all sorts of reasons. You know how maddening it is when you buy a new electronic gadget and find that it's just not user-friendly, that obviously nobody bothered to let a user not involved in the original design test it out? Well, in addition to all the points of spelling and grammar and style and consistency, that's the copy editor's role: to make sure the story makes sense to somebody who doesn't already know the story."