Did you ever have a babysitter who told you "don't think of purple pandas"? And of course what are you going to do but think immediately of pandas in the loveliest shade of purple, right? Someone says a word, or suggests an image, and even if they've put it forth in a negating sense, the visual hovers there. Sure, maybe it has an X over it in your mind, but the image isn't exactly erased. That's what's happening here with all these negative prefixes and suffixes: "un-" and "-less." Put them together and you get "unless." Hmm—that's interesting, isn't it? "Unless" is one of those funny words describing a condition that will happen without something else happening (for example, "we'll be together forever… unless one of us should die"). And this word, "unless," can be applied to the poem as a whole, especially when an image is given on one hand, and X-ed out at the same time for the reader.
Line 8: It's funny when a poet says something's nameless. Isn't poetry all about naming the unnamable, about using words in a close approximation of a meaning that is always just a little bit out of reach? Here the air is moving in that way, that way… oh, it's right on the tip of our tongue, but also miles above it.
Line 10: "Unmurmuring"? Will you look at all those U's and M's and R's and N's? The world just looks like a murmur, and certainly sounds like a murmur (making it an onomatopoeia). Heck, maybe it even tastes like a murmur, but it just isn't a murmur, courtesy of that "un-" hitching a ride at the front. What the word does do, though, is echo murmurs past.
Line 20: When you're a poet, you can just invent words. Why not? You've got the license! Both "Unrocked" and "unrippling" were unwritten, at least until Warren unraveled them. (Okay, we'll stop now.) By using a known word in its negative form, the poem asserts and negates in one fell swoop. If he'd said dark was rocking and rippling, he would be granting the dark a greater creative power. Instead, while evoking these waves and ripples, he also shows them in a state of settling.
Lines 23-25: A word like "voice" in the mouth of a poet always has particular status. "Voice" to poets is like a picture I.D. What would a poem be without a voice? Warren brings this one step further by introducing "debate." Not only is the voice muzzled, but so is any dispute or opposition. Everything is defused.
Lines 27-28: Just in case you didn't get this technique of giving and taking as a simultaneous act, the poem flaunts it here. "Hope" is paired with "hopeless," "fear" with "fearless," and just in case you found this somehow consoling, Warren winds up the one-two punch with a roundhouse that KOs all of human "history."
Lines 33-36: The speaker brings things home to a personal level with these lines. His beloved is mentioned for the first and last time. The speaker assures her that he doesn't love her less, now the heart is mortal or now that the dark is stealing everything light once gave. Hey! What did we say about giving and taking? The sun gives the world and life; dark night will "revoke" it all by degrees. But love persists. In all this darkness, there is that glimmer.