In A Poetry Handbook, Mary Oliver writes this about prose poems:
"What you see on the page is a fairly short block of type--a paragraph or two, rarely more than a page. It looks like prose. Perhaps it has characters, perhaps not. Often, it is pure description. It usually does have the same sense of difference from worldly or sequential time that one feels in a poem. And it does certainly ask to be read with the same concentration, and allowance for the fanciful and experimental, that we give the poem.
"Because the prose poem is brief--or perhaps just because it is something other than a poem--it seems more often than not to have at its center a situation rather than a narrative. Nothing much happens, that is, except this: through particularly fresh and intense writing, something happens to the reader--one's felt response to the 'situation' of the prose poem grows fresh and intense also."
I wish I'd had Oliver's definition at hand during my thesis defense. The only question that I had trouble answering was from a prof who didn't like prose poems. All I could tell him was my process--that when line breaks feel stilted or unnatural, I write in prose. Or, on the other hand, when the ideas and images are coming too fast to worry about line breaks. Either way, the primary quality of prose poems (I think) is immediacy.
Which is why I had so much trouble with Michael Fried's prose poems in The Next Bend in the Road. Here's an excerpt from a poem called "The Wound":
"The following is based on a prose poem by Picasso's friend Max
Jacob. In the first decade of the twentieth century, a Japanese youth with
a talent for drawing, who had recently lost an adorable younger sister to an
obsure illness, left home to seek his artistic fortune in France."
Frankly, I don't see any similarities between Oliver's definition and what I just quoted here. I don't get it. (And in case you're wondering, it just goes on like that for another half a page.) It seems that paragraphs like these are what give critics the ability to say prose poems are not really poetry.
But then there's this (from "John Montiere answer to question three" by A. Van Jordan):
kicking from between her legs. Blood paints the skin of the midwife's
hands and arms up to her elbows. Blood paints my son's legs up to his
waist; all i can see is his kicking. He is grounded, feet first. His
head emerges and he sings his song."
So different! The language isn't unusual, the description not overdone, and yet, I can clearly identify this as poetry, where I can't in the Fried example. And I'm certainly striving for something more like A. Van Jordan's prose than Fried's.