Is there anything harder to define than poetry? Beyond matters of prosody, imagery, cadence, and such—the mysterious essence and quiddity of poetry? What, for instance, makes the odd verse quintessentially poetic, engraved on the mind, conjuring up voluptuous feelings when we repeat it to ourselves as a mantra? The quality that, in J. A. Cuddon’s apt phrase, “at once transcends and supports the meaning”? Take, for example, Thomas Nashe’s “Brightness falls from the air;/ Queens have died young and fair,” where the second verse is more charged with feeling, yet the first lingers more hauntingly in the memory. (I realize that some think air a textual corruption for hair, but let us not split hairs.) The entire verse is an image, with the progression of vowels from brighter to darker mirroring the meaning; but it is that unusual falls rather than, say, fades that shocks the line into poetry.

Or take Auden’s “Lay your sleeping head, my love,/ Human on my faithless arm,” where, again, the second verse is more charged and provocative, but the first is more “poetic.” Partly so because, instead of the expected sleepy, we get the almost paradoxical sleeping; and partly because of those liquid l’s at the beginning, middle, and end of the line—the medial l, as it were, slightly masked by the sthat precedes it—as if hooded by a lowered eyelid. It is in such near-intangibles that poetry resides; they are what, in Frost’s famous dictum,