I work to post daily in this webspace because I want to stay in practice in writing and because I do want people to read what I write. Sometimes, as has been evident, I strive to do so in snippets of verse. I rather think that they do not often go over well, judging by the page view figures to which I have access. I have to think that it is because my poetry tends to be bad, as most poetry is. From that, I think that some assertion of what makes for a good poem--and thus the absence of which makes for a bad one--is in order. It will be subject to contestation, of course; any such assertion is. But argument and discussion do not threaten an earnest scholar such as I attempt to be.
Not long ago, I made the assertion in this webspace that poetry is writing that organizes meaning by the line. A good poem will necessarily be a poem, so it will necessarily organize its meaning by the line. It will need to do more, though, to be good. Presumably, it will need to make reference to something beyond itself, some invocation of outside materials and sociocultural constructions, as it attempts to make meaning. Usually, this will come in the form of simile, metaphor, analogy, allusion, or something similar. Shakespeare's Sonnet 116, regarded as a fine little poem, does so prominently in the equation of love and stars for ships to sail by (as well as others less obvious and less fit for mixed company). Milton's Paradise Lost, one of the masterworks of English literature, embeds reference after reference after reference in a showy display of the poet's erudition. Completing the canonical trinity, Chaucer (who hath a blog) relies on a misunderstanding of Scripture in his Miller's Tale (per an old professor of mine)--which requires that the audience have an appropriate understanding, that they understand the reference to the Flood.
More, a good poem will perhaps respond to its moment, but it will also respond to something other than merely its moment. This is, perhaps, where much of my own verse falters, being strictly occasional and not speaking much to concerns beyond "expressing me" at the moment of expression. The examples above--Shakespeare's Sonnet 116, Milton's Paradise Lost, and Chaucer's Canterbury Tales--all do so, speaking to the persistence of love, foundational Christian cosmology, and human foible. Other examples do, as well. John Donne's "The Flea," perhaps my favorite poem, in addition to ranging far afield in pulling in its references speaks to the lustful longing common to the young, and to young men particularly. Mark Strand's "Eating Poetry," another favorite, bespeaks either the dangers of too much study or the essentially liberating nature of it, a transcendence frequently sought.
Perhaps also that ambiguity, that ability to sustain multiple interpretations simultaneously, marks good poetry. Going into how meanings can be perceived in the texts will no doubt bore many; those who are interested in it can find resources to learn more about how to do so. (Why else literature classes?) Even so, all of the examples listed,* as well as others too numerous to reference in this venue at this time, bear multiple interpretations, support multiple understandings, each of which bespeaks some response to something other than the mere moment of composition. And I think that much of my work, as well as that of many others fails to do so. But I am working to improve.
*I am aware of the restrictions on my examples. Make of them what you will.