Plato's “Ion”: What’s the Problem with Poets?

Buffalo Poetics (membership required) has recent thread on spirituality and poetry, also philosophy centered, especially in consideration of Wittgenstein. Here poetry examined through another philosophy lens raises the the question of its morality. Via Rufus @ The League of Ordinary Gentlemen Plato's dialogue Ion (Dialogue IX) is brief and seems to address a rather trifling question: Do poets know what they're talking about? If Homer composed beautiful passages about chariot-driving, does his art include technical knowledge of that skill? This is, to put it nicely, not what most of us consider to be a pressing concern. The School of Athens, Raphael It matters though because the implications of this short piece shed light on one of the most troubling ideas in Plato's corpus: that the ideal city (Republic, I-IV) would exile its poets. Living after the twentieth century, it's hard to accept the proposal that a leader could make his citizens better people by banning art. It's also hard to understand the idea given Socrates's deep admiration for poets, especially Homer. Although he expels the poets from his ideal city, it is also clear that he does so with great regret. So what exactly is the problem with poetry?