A poem should be motionless in time As the moon climbs,
Here's some more of that metaphysical vibe with all the talk of being "motionless in time." In the physical world, things are always moving and working with time. But here, the speaker is pointing to a different kind of existence that's beyond all the physical stuff. So it's metaphysical, otherworldly, and therefore more transformative in a sense.
It's also timeless in a sense, considering that, if a poem is "motionless in time," we can't restrict it to a particular period or time. According to the speaker, a good poem is beyond qualification because it works in this metaphysical kind of realm that can't be held to any one place or time. It endures the passing of time.
So again, we sense the necessity for a poem to be without all of the concrete physical stuff. It has to tap into those parts of our humanity that we can't really explain with concrete words but can only sense and feel. And those parts of our humanity tend to carry on from generation to generation, no matter a person's time or place.
The added imagery and simile of a moon climbing in the sky also gives a sense of endurance beyond the stipulations of time. The moon has always been the moon and people have more or less always been people. And yet if we imagine a moon climbing in the sky, we might sense another paradox here since the moon can't exactly be "motionless" if it's climbing, right?
If we imagine the moon climbing we also get the speaker's sense of an existence beyond the earthly physical stuff. There's a kind of magical connotation of the moon's climb as it floats effortlessly above us. And again, that's also how a poem should feel.
And of course we have another perfect couplet with "time" and "climb." So the speaker is flipping back to the older conventions of perfect rhyme for us once more, keeping things balanced.
Leaving, as the moon releases Twig by twig the night-entangled trees,
Here the speaker is elaborating on the magical/metaphysical movement of the moon. As the moon rises, it appears to move away from the earth and all of its trees, just as a poem should release the physical world too. A poem must "leave" the concrete world and climb like the moon climbs in the sky.
The imagery of "night-entangled trees" also has the connotation of the earth being tangled up in itself. So the need for a poem to move beyond all the tangles is underscored even more here.
And of course we have another couplet in slant rhyme again, with "releases" and "trees." Hear those E and S sounds? Don't forget to check out "Sound Check" for more on this kind of assonance and consonance.
Leaving, as the moon behind the winter leaves, Memory by memory the mind—
We get more of the motif of "leaving" here to emphasize the speaker's idea of poetry being beyond the physical. The repetition helps us as readers to also sense ourselves "leaving" the world of the physical for the world of the poetically metaphysical.
Even memories are associated with the physical in line 14, but in this case the speaker appears to be pointing towards the idea of personal/subjective motivations. So a poem should also never be limited to personal memories. It's bigger than any one individual person.
The imagery of the "moon behind winter" also adds to the sense of absence of the individual and his memories. A winter moon looks awfully bare and plain to see, as there aren't any leaves obstructing our view. Likewise a poem should be equally plain to see without any distractions of personal motivations.
Notice too the parallelism we see here in line 14 compared to line 12. We have the same "thing by thing" clause recurring, which again tells us that the speaker is playing with the poem itself. He's not just talking about good poetry, he's also demonstrating the various ways in which to create a good poem through some of the devices we've seen thus far. Clever guy.
A poem should be motionless in time As the moon climbs.
We have a little refrain here that, just like before, is reminding us of the timelessness of good poetry. It's not moving in the present, past, or future. It resides in a place that's not subject to the limitations of time.
Notice too that the speaker is playing with his poem again. The use of a refrain here gives us a sense of more conventional poetry (where refrains are pretty common) and yet the device is nestled in some freer modern stuff as well (slant rhymes, not so common imagery).
So again, our clever speaker is speaking about good poetry while also demonstrating how it's done. He's also pointing out that the nature of poetry should also be about freedom and allowing it to do what it wants rather than forcing it to "mean" or "be" something. (Check out "Form and Meter" for more on refrains.)