We reach and strain with our thoughts, trying to grasp what poetry is, trying to somehow distinguish it from all that is not poetry, but without success.  Then we come across something as simple as this statement by A. E. Housman:

Poetry is not the thing said, but a way of saying it.”

And it is as though the sun has risen, dispelling the darkness; because that is exactly what poetry is.  It does not lie in the thing said, however significant it may be.  It lies, rather, in how that thing is said.

All of the traditional paraphernalia of poetry, whether rhyme, rhythm, alliteration or assonance, are merely means to this end — saying the thing in a way that makes it poetry.  Their use, of course, is no guarantee at all that the result will be poetry, but we know that they are used with poetry as the goal.

Prose, we may say then, is the reverse; it is not so much how a thing is said as what is said.  It is meaning that is important and the key element.

We should not misunderstand this and think that poetry has no meaning, but rather that what meaning it carries is molded to the manner in which it is presented, however important the meaning may be — if it is to be poetry.

We may separate the meaning from the poem by explaining it in ordinary, everyday English, but by doing so we cause the meaning to lose its poetry.  If that were not so, we would all constantly be speaking poetry.

 So poetry is a way of saying something, a special way, and there are various tools and manners that may be used in so speaking — again like rhyme and measure and rhythm, alliteration (repetition of consonant sounds) and assonance (repetition of vowel sounds), but not all of these tools are essential for writing a poem.  It all comes back to a way of saying something.

We may go on to remark that obviously, then, poetry is not ordinary, everyday speech, which concentrates more on just saying a thing than on how that thing is said.  Poetry is the changing of one’s common speech pattern to say a thing in a way that makes it more pleasing or interesting or effective, or all three combined.

Sometimes the line between poetry and ordinary speech may seem blurred at first, but with a little reflection it is recognized nonetheless.  When W. H. Auden wrote his poem September 1, 1939, he was talking about the outbreak of World War II, the invasion of Poland by German forces — and he was seemingly conversational in doing so; we see, however, that this would not have been his everyday speech — not the way he ordered a meal, nor the way he talked to a friend.  And it is that little change that makes all the difference in transforming something from prose to poetry:

I sit in one of the dives
On Fifty-second Street
Uncertain and afraid
As the clever hopes expire
Of a low dishonest decade;
Waves of anger and fear
Circulate over the bright
And darkened lands of the earth,
Obsessing our private lives;
The unmentionable odour of death
Offends the September night

 We find the end rhymes — dives / lives, bright / night, afraid /decade.  And we find “odd” ways of saying things, such as

Waves of anger and fear
Circulate over the bright
And darkened lands of the earth…

Eliminate the rhyme, however, say instead that people all over the world are angry and afraid, and the poetry dissolves — vanishes into prose.  

We tend to think that poetry is cut up into lines (and it usually is), while prose is divided into paragraphs.  But actually poetry and prose are somewhat like human gender behavior, which shades from one extreme to the other.  Some men are very stereotypically masculine; others are very stereotypically feminine; but between the two poles are found all the people who fall somewhere between.  In the change from prose to poetry, as in human gender roles, we find a graduated scale.  Some poets border on prose, but never fall completely into it, or they would not be poets.  There is still something to their way of saying the thing that is recognizable as poetry.

But the matter is a little more complex.  Even in prose, people often do not write as they commonly speak.  They leave little things out; they use “big” Latin or Greek-based words, instead of plain and simple Anglo-Saxon; they say things more concisely, and perhaps more effectively.  There is a vast difference in even so small a matter as an invitation to dinner:

1.  Do you wanna have dinner with me tomorrow?
2.  Your presence is requested at a dinner honoring the accomplishments of H. N. Featherwood.

And then there is poetry:

Let us go then, you and I,
When the evening is spread out against the sky
Like a patient etherised upon a table; 

One comes to recognize and to distinguish poetry from the other two kinds of speech, the ordinary and the formal.  What one must be wary of is prose that is disguised as poetry by being divided into lines in imitation of poetry.  Some people who write this way think they are writing poetry, and some critics are deceived into thinking the same.  But those who realize that poetry is not just dividing prose into lines on a page, but rather is a way of saying something that is different both from ordinary and formal speech, will not be fooled.

Some would-be poems include the bare minimum of the special way of saying something that is poetry, and sometimes not even that.  We should not confuse that kind of writing with the “conversational” yet quite poetic manner of Walt Whitman in his Shut Not Your Doors:

Shut not your doors to me proud libraries,
For that which was lacking on all your well-fill’d shelves
       yet needed most, I bring,
Forth from the war emerging, a book I have made,
The words of my book nothing, the drift of it every thing,
A book separate, not link’d with the rest nor felt by the intellect,
But you ye untold latencies will thrill to every page. 

But, you may say, no one talks like that!  And I reply that you have grasped the point.  No one talks as Walt Whitman wrote in poetry.  You may think they do for a few words or a line, but the poetry will out.

The same may be said for Robert Frost, another sometimes even more “conversational” poet.  Look at the beginning of his Birches, where he fools us into thinking that we are just listening to the rambling conversation of some New England ruralite, and it is only gradually as we read on, and feel the rhythm, and begin to sense his increasingly revealing way of speaking, that we become aware that what seemed to begin as conversation was actually just the path into poetry:

When I see birches bend to left and right
Across the lines of straighter darker trees,
I like to think some boy’s been swinging them.
But swinging doesn’t bend them down to stay.
Ice-storms do that.  Often you must have seen them
Loaded with ice a sunny winter morning
After a rain.  They click upon themselves
As the breeze rises, and turn many-colored
As the stir cracks and crazes their enamel.
Soon the sun’s warmth makes them shed crystal shells
Shattering and avalanching on the snow-crust —
Such heaps of broken glass to sweep away
You’d think the inner dome of heaven had fallen. 

When reading Frost, one often has the feeling of being tricked into submitting to some sort of peculiar farmer’s incantation, because what seems ordinary speech at first increasingly weaves a charm of words, as though Frost were a kind of New England shaman chanting away, putting a folksy spell upon us, as in his After Apple-Picking:

My long two-pointed ladder’s sticking through a tree
Toward heaven still,
And there’s a barrel that I didn’t fill
Beside it, and there may be two or three
Apples I didn’t pick upon some bough.
But I am done with apple-picking now.
Essence of winter sleep is on the night
The scent of apples: I am drowsing off. 

This incantatory nature of his writing is one of the most pleasing things about Frost.  And again, it is a way of saying it; it is poetry.

So we know, in theory, what poetry is and what it is not.  But that does not mean we have defined poetry.  We must still be able to distinguish between poetry and mere verse — between what is genuinely poetic and what just uses some of the tools of poetry but does not succeed in being poetic.  For that we can only return to another statement of Housman: that poetry is known by its effect on us.  But here we are back again at the beginning, reduced to saying that “good” poetry is a matter of opinion and taste formed by education and experience.