What distinguishes poetry from prose? Any poetry critic who can’t tell you should turn in his union card. Yet the answers to this question, from the history of criticism, are surprisingly unsatisfactory. The old Horatian formula of “instruction and delight” is not unique to poetry. Wordsworth offers “emotion recollected in tranquility,” a definition in which neither element seems strictly necessary, and which again applies equally well to prose. Other critics, especially poet-critics, take refuge in impressionism, like Emily Dickinson’s “if it feels like the top of my head has been taken off, that is poetry.” Paradise Lost has not, I suspect, taken off the top of anyone’s head for quite some time, but no one calls it prose on that account. Most critics do not trouble themselves over the question at all: they assert, like Justice Stewart on pornography, that they know it when they see it. But remarks like “that isn’t poetry” are slung about frequently, and even offered as criticism. Clearly the question is worth troubling over.

I suggest a more prosaic definition, so to speak: a poem is what scans. Two objections suggest themselves immediately. The less serious is that it fails to exclude doggerel, like obscene limericks. But if obscene limericks aren’t poetry, are they prose? Or is there some third category of neither/nor? If we do not deny the title of prose to the speech of Monsieur Jourdain, I see no reason to deny the title of poetry to the limerick. Poetry, like art, is not an evaulative but a technical term.

The more serious objection is that my definition excludes vers libre, which doesn’t rhyme, doesn’t scan, but is poetry nonetheless. To deal with this requires a brief theoretical preamble. The basic foot in English is the iamb, an unaccented syllable followed by an accented one. All natural speech in English is iambic. The previous sentence, for instance, is a line of iambic pentamenter (with a feminine ending).

Iambic rhythm so dominates English that its avoidance often sounds comedic, a fact that Lewis Carroll exploited brilliantly in his Longfellow parody, Hiawatha’s Photographing. It is written, like the Longfellow original, in unrhymed trochees, which are iambs in reverse.

Next to him the eldest daughter:
She suggested very little,
Only asked if he would take her
With her look of “passive beauty.”
Her idea of passive beauty
Was a squinting of the left-eye,
Was a drooping of the right-eye,
Was a smile that went up sideways
To the corner of the nostrils.

Hiawatha, when she asked him,
Took no notice of the question,
Looked as if he hadn’t heard it,
But when pointedly appealed to,
Smiled in his peculiar manner,
Coughed and said “it didn’t matter,”
Bit his lip and changed the subject.

Nor in this was he mistaken,
As the picture failed completely.

The ridiculous matter, set to trochees, is rendered supremely ridiculous. Other non-iambic meters lend themselves to similar effects, like George Wallace’s beloved double dactyls. Feminine line endings tend to undermine iambic movement, and although some serious poets, like Greville and Dryden, are partial to them, they are seen more often in light verse like W.M. Praed’s.

When writing poetry in English, you can studiously adhere to iambic meter or you can studiously avoid it. Anything in between is prose. Free verse consists, essentially, in avoiding any metrical norm by varying the movement continuously. This is much harder than it sounds.

An example may help. Let’s begin with a free verse poem that obviously is a poem, W.C. Williams’ To a Dead Journalist. Read it first, then look at the scansion. Primary accents are bold, secondary accents italic:

Behind that white brow
now the mind simply sleeps —
the eyes, closed, the
lips, the mouth,

the chin, no longer useful,
the prow of the nose.
But rumors of the news,
unrealizable,

cling still among those
silent, butted features, a
sort of wonder at
this scoop

come now, too late:
beneath the lucid ripples
to have found so monstrous
an obscurity.

Williams wrote in a letter that for him the purpose of free verse was to vary the speed of the foot, and one could not find a better demonstration. The lines range from two to seven syllables, and no two scan, let alone move, alike, even if we disregard strength of accent. The short lines, like 4 and 12, tend to be slow, and the long lines, like 2, 7, and 14, tend to be fast.

Discernible consecutive iambs appear in three places, with point. The list of features in lines 4 and 5, bracketed by the heavily accented monosyllable “closed” and the lightly accented appositive “no longer useful,” is echoed, metrically, by their description in line 10. Williams produces a metrical miracle in lines 12 and 13, with its heavy iambs, after which the poem trails off in a sort of low mutter. The colon at the end of line 13 cleaves life from death absolutely. Continuous variation is impossible to sustain, and would weary the reader in any case, which is why good free verse is short, and scarce; but this poem succeeds completely.

For comparison most any selection from the poetry magazines would do, but let’s pick on someone famous. Let’s pick on Frank O’Hara. This is an excerpt from The Day Lady Died, which in its entirety runs too long for my purposes; you’ll have to trust me that the rest of it is exactly the same:

I walk up the muggy street beginning to sun
and Miss Stillwagon (first name Linda I once heard)
doesn’t even look up my balance for once in her life
and in the Golden Griffin I get a little Verlaine
for Patsy with drawings by Bonnard although I do
think of Hesiod, trans. Richmond Lattimore or
Brendan Behan’s new play or Le Balcon or Les Nègres
of Genet, but I don’t, I stick with Verlaine
after practically going to sleep with quandariness
and for Mike I just stroll into the Park Lane
Liquor Store and ask for a bottle of Strega and
then I go back where I came from to 6th Avenue
and casually ask for a carton of Gauloises and a carton
of Picayunes, and a New York Post with her face on it
and I am sweating a lot by now and thinking of
leaning on the john door in the 5 Spot
while she whispered a song along the keyboard
to Mal Waldron and everyone and I stopped breathing

Here the conscious variation one finds in Williams is absent. There is no point in scanning this: it has no scansion. Note the indigestable chunks of iambs, like lumps in the mashed potatoes, in line 2, lines 4-5, and lines 16-17. (There would be more, and they would be more obvious, if not for O’Hara’s habit of stringing together sentences with “and” to simulate the breathless effect that Williams achieves without such cheats.) Any reasonably sensitive reader will recognize this passage as prose, and not very good prose either. O’Hara, along with other bad poets, is sometimes praised for his “prose rhythms,” which is like praising a mouse masquerading as a rat for being a mouse after all. O’Hara, says one reviewer, “expand[ed] our ideas about what is poetic.” What say we contract them a little?

(Update: Jim Henley accuses me, correctly, of treating the term “poetry” normatively while taking others to task for doing the same thing. I should have picked a “poem” that I thought was prose but good prose, instead of the one I did. I’ll think about a suitable example and post it when I find it. Kevin Holtsberry comments. Was it really that arcane? mallarme comments.)