A poem should be palpable and mute As a globed fruit,
Ah, our speaker wastes no time creating the perfect paradox of what a poem "should be." A paradox, by the way, is a device that makes words appear as if they lack sense because the idea is contradictory. But if we put the idea in context with the subject, we can kind of make sense of it.
Here, since we're talking about the ever-elusive nature of poetry, we can sense what the speaker is driving at. A poem should be palpable (able to be felt), but it should also be "mute," meaning it shouldn't shout ideas and truths at us. But wait. Isn't a poem made out of words? If so, how can a poem be mute? Hmm. Therein lies the paradox…
The speaker seems to be saying that we should sense the poem but we shouldn't feel as if the words are yelling at us and throwing a bunch of "meaningful" ideas at us.
The simile the speaker includes in these lines compares a poem to a "globed fruit." What do we make of that? Let's start by working with the imagery of a "globed fruit."
A fruit is palpable since we can hold it in our hands, right? At the same time, since it's encased in a globe, or perhaps just spherical, we can't really get inside of it either. So we're sensing the fruit without feeling bombarded by its insides. And according to the speaker, that's how a poem should read as well.
So the simile here is quite poignant without being overly cliché. From the very beginning we sense the speaker not only telling us what a poem "should be," but also demonstrating his beliefs predominately through the imagery of the poem itself.
And of course, the little couplet we have here that rhymes "mute" with "fruit" adds to the poem's treatise on poetry. Poems are known to rhyme, so the speaker is kind of playing with his own words and ideas here, blending the conventions of rhyme with the more modern practice of predominately relying on images rather than "truths." (For more on rhyme, check out "Form and Meter.")
Dumb As old medallions to the thumb,
A poem should be dumb? Huh? Aren't poems supposed to demonstrate the fancy pants of a true intellectual?
Perhaps "dumb" here doesn't mean dumb in the sense of "duh." Rather the speaker appears to be pointing to the idea of a poem being mute and without any conscious effort to mean something. It shouldn't try to be smarter than the reader, or aim to deliver some higher "truth" about the world.
Line 4 highlights the feeling of timelessness that a poem should also carry. The simile here that compares a poem to "old medallions" gives us a sense of the enduring quality of poetry. Long after our bones are dried up, those "old medallions" remind us of our history, where we've been, and how humanity has progressed over the years.
But those medallions are also "dumb" in the sense that they're not trying to prove anything. They just exist as a relic of man's history and a reminder of others that have come before us.
So we also sense a connection that all men share with the history of mankind. Hence the subsequent timelessness that a poem should also have that doesn't limit man to any one place or time.
Notice too the perfect couplet we have here (rhyming "dumb" and "thumb"), just like the previous lines. Check out "Form and Meter" for more on that technique.
Silent as the sleeve-worn stone Of casement ledges where the moss has grown—
Ever seen a "casement ledge"? Here's one, just in case.
So, just like that painting, the "sleeve-worn stone of casement ledges" means exactly that. Folks, especially before the days of Netflix, would often look out of their windows with their elbows upon the window ledge. All of the elbow action over time made the casement ledge look worn.
But don't forget, the series of images we've been seeing are also part of the extended metaphor of what poems "should be." A poem should be just as "silent" as the casement ledge that's been worn over time. It shouldn't shout, "Hey, get your elbows off of me!" or anything like that.
Also, if we think about a casement ledge on a window, we might also imagine a poem being a window through which to see the world. Can't really look out the window without that casement ledge, can you? By the same token, you can't really see the world without the transcendental power of art and poetry.
And since we have the added image of moss in line 6, we sense the continuation of time even more. The moss grows, the ledges become worn, and a poem should likewise be just as natural and effortless as both things.
We have another couplet too, rhyming "stone" and "grown." So by now we're noticing the kind of form that the speaker is sticking with. We've got three sections with two couplets in each stanza, most being in perfect rhyme. Again, don't forget to check out "Form and Meter" for more.
A poem should be wordless As the flight of birds.
Ah, here's that famous head scratching line. How can a poem be "wordless"? Going by what we've already seen, we understand the speaker's idea of a poem being silent in the sense of never shouting truths and meanings into our ears. In that way too, it should be "wordless" without making us feel tied to concrete ideas.
So the simile we see here adds another layer to the speaker's ideas about poetry. The "flight of birds" gives the added bonus of freedom and lightness. With that image alone, we sense the speaker's emphasis in the necessity for poems to sound free and above the concrete physical world of noise and words. Check out our "Symbols, Imagery, and Wordplay" section for more.
The couplet we see here isn't perfect but is rather written in slant rhyme. The ending consonance joins the S sounds in "wordless" and "birds" without sticking to the exactly rhyming patterns we've seen. There's even some internal rhyme in "word" and "bird" that jives pretty nicely.
So the speaker, through the poem itself, is reminding us of the modern influence he's working with. There are the classical/perfect parts and the more modern/imperfect parts. And just like poetry is a combination of the past and present, so is the speaker's exercise in rhyme.