Sylvan historian, who canst thus express A flowery tale more sweetly than our rhyme: (lines 3-4)
The speaker thinks highly of the urn’s skills as a historian and storyteller and compares them favorably with his own. But we have no basis on which to judge, because we only hear about the urn through the poem. Wisdom never seems to come directly from the source. The wisdom of the Ancient Greeks is filtered through a piece of marble and then through the poet’s verses.
What leaf-fringed legend haunts about thy shape Of deities or mortals, or of both, In Tempe or the dales of Arcady? What men or gods are these? What maidens loth? What mad pursuit? What struggle to escape? What pipes and timbrels? What wild ecstasy? (lines 5-10)
The poem isn’t just a description or praise of the urn. It also charts the speaker’s progress as he tries to figure out what’s going on. He arrives at knowledge by asking a lot of questions, and these questions serve a rhetorical purpose. They let use know what he’s looking at – in this case, a chase scene with "men or gods" and beautiful maidens. But, as these questions show, the speaker’s knowledge is imperfect. He could be misinterpreting the urn.
Heard melodies are sweet, but those unheard Are sweeter; therefore, ye soft pipes, play on; Not to the sensual ear, but, more endear'd, Pipe to the spirit ditties of no tone: (lines 11-14)
Could music be the highest form of truth? The speaker believes that truth and beauty are the same thing, and beauty seems to change from moment to moment, like a song. The speaker thinks that music is the most intense and immediate art form. Literature connects with the emotions and the intellect, while music plugs directly into emotions. Poetry is generally considered more "musical" than sculpture, but the speaker claims to hear "melodies" emanating from the urn. That is, silent melodies. Does this paradox make sense, or does the emperor have no clothes?
Thou, silent form! dost tease us out of thought As doth eternity: Cold Pastoral! (lines 44-45)
Once again, the speaker suggests that the wisdom of the urn is connected to its silence. The line "tease us out of thought" is one of the most mysterious in the poem. It could indicate that the urn doesn’t really have wisdom to impart; that it can only cause confusion on the part of the observer. Or it could mean that the wisdom of the urn is higher than or "beyond" mere thought, which is conducted primarily through language.
'Beauty is truth, truth beauty,—that is all Ye know on earth, and all ye need to know.' (lines 49-50)
Keats distills the urns message down to these two simple, homey-sounding lines. Is this a cop-out, as T.S. Eliot famously believed? Or does the beauty of these lines, combined with their vague and confusing content, only prove the point that Keats wanted to make? And it’s a radical point, to be sure. If the speaker had his way, moral education would consist not of rules and life lessons, but of the experience of beauty. By the way, have you noticed how when you visit a beautiful place with other people, everyone acts a little nicer?