From The Paris Review:
John was a true poet-critic, in whose work poem and essay inform one another and sometimes change places. One mark of their fellow traveling is a shared commitment to the art of explanation. The basic principles of the sugar-cube story are everywhere in his prose, especially in his perpetual delight at the precision and elegance of a good definition. His virtuoso guide to poetic form, Rhyme’s Reason, begins by telling us that “The study of rhetoric distinguishes between tropes, or figures of meaning such as metaphor and metonymy, and schemes, or surface patterns of words. Poetry is a matter of trope; and verse, of scheme or design.” Could it be said in fewer words? Another Hollanderian impulse is expressed here too, his love of taxonomy, dividing a subject into molecular simples. Many of his great essays make their sense of fundamental topics—like the making of refrains, or asking questions in poetry, or answering them—by counting the possibilities. In “Poetic Answers,” an answer can be a fact, a promise, an imperative; it can bring closure, or refuse it; and on and on, with examples drawn from anywhere and everywhere in English poetry.
If you read “Blue Wine,” you’ll see the same mind at work, or at play. (John loved to consider and confuse the two.) The poem got its start on a visit to Saul Steinberg’s house, where he saw a line of curiously labeled, clear bottles arrayed on a window sill, all filled with the same blue liquid. The poem’s root question is, What is that stuff? and each of its eleven sections offers a hypothesis, indeed, several hypotheses. Some “wise old wine people” speculate that it is red in the cask, blue in the light, the opposite of blood; or that it is no particular blue, but the cosmic blue of generality itself. Then again, it may have been made by vintners after a recipe in Plutarch’s lost essay “On Blue Wine.” Or again, perhaps it turned blue in the cask at the laugh of a Zen master, who posed its surprising color to his students as a koan. Or it is German, Das Rheinblau; or French, Château la Tour d’Eau; or Romanian, “the funny old / Half-forgotten Vin Albastru.” And so on: the poem is giddy with is own answers, its self-begetting explanations.
Of course, as Wittgenstein reminds us, in one of John’s favorite aphorisms, all explanations come to an end somewhere. It was important to how he understood his own career that somewhere along the line he turned away from “essayistic speculation” and began to write “less discursively, more puzzlingly”—so he told The Paris Review in 1985. The explanations, like many in “Blue Wine,” become as likely to be questions of their own.
More here. (Note: My co-author Sara Suleri and I greatly benefited from Rhyme's Reason during our attempts to translate Ghalib. We are deeply saddened by this loss.)