 If Ion is an exegete or explicator of Homer’s poems, he must surely understand what the poet means, else he could not explain the poet’s thoughts. This seemingly commonsensical point is asserted by Socrates at the start (530c1–5), and happily accepted by Ion. However, if Ion understands what the poet says about X, and judges that the poet speaks best about X, he must be in a position to assess other poets’ pronouncements about the subject in question. For example, Homer talks a great deal about how war is waged; as an expert on Homer who claims that Homer spoke beautifully about that subject (in the sense of got it right), Ion must be in a position to explain just how Homer got it right and how Hesiod, say, got it wrong, as a series of simple analogies show. If you can knowledgeably (531e10) pick out a good speaker on a subject, you can also pick out the bad speaker on it, since the precondition of doing the former is that you have knowledge of the relevant subject matter. But this seems to contradict Ion’s assertion that he can explain only Homer, not the other poets.