Bad art does what you expect. To me, it's not truly a poem if it merely says what most intelligent, well-meaning people would say. In the other direction, total surprise is babble, it's meaningless; I don't mean to say that one is on a quest simply for novelty. But your responsibility is, even if it's only to versify something you perceive as truth, to put that truth or homily into a rhyme in such a way that you are transforming it. Your job is to do something that the reader didn't already have.
- Robert Pinsky, in interview with Harry Thomas' class at Davidson College, as published in Talking with Poets (Handsel Books, 2002). You can read the full thing here.