If poetry doesn’t have to rhyme and stuff, what’s the difference between poetry and prose that’s been chopped into short lines?
Poetry has an internal rhythm to it that chopped up prose doesn’t.
The rhyming is just a bonus.
The language of poetry is also aiming to be more concise and precise than prose - when it’s successful, it is saying a lot with very few words, whereas in prose, it’s quite acceptable not to be concise at all (although it’s probably better if it is precise). Prose that has this density is often referred to as ‘poetic’.
I’d say that the ‘short lines’ definition of poetry isn’t any more true than the ‘it rhymes’ definition. It’s pretty easy to take the mickey out of poetry (particularly bad poetry) by chopping up inane prose into lines of four words each, but that doesn’t actually say anything about what people who know or care about poetry believe about the artform.
Here’s a demonstration, taken from a great work of literature, that doesn’t make any sense as poetry:
Prose speaks.
Poetry talks.
I dont think there’s a line where you can say “this is poetry. across THE LINE, it is not poetry, but prose”
The more “poetic conventions” a piece of work uses, such as rhyme, conciseness, stanzas and lines, rhythm, in no particular order, the more “poetic” it is.
And, to be fair, if an artist wants to call their work “poetry”, I will give them the benefit of the doubt. But that doesnt mean its truly “poetic.”
F’rinstance, I think the most poetic works in the 20th century were the famous parts of the “I have a dream” and “we will fight them on the beaches” speeches, moreso than any formal poetry. Then again, i’m a sucker for parallelism 
In all honesty, in all my lit classes and listening to the Writer’s Almanac daily for several years, I can say that I never recall encountering a poem that fits that description. If anything, my experience has been that poetry “says” less by using less precise language, whereas from poetry one may infer more because of that fact.
This could work as poetry.
Actually, what you’re contrasting is not “prose” and “poetry” but "prose and “verse.” “Poetry” is a kind of praise word, an honorific term for particularly powerful, emotionally affecting, often pithy, often metaphorical, often rhythmic pieces of writing, whether in prose OR verse. (Sections of MOBY DICK, for example, are rightly felt to be examples of “prose poetry,” as is King’s “I Have a Dream” speech, and many other examples.)
Further, you’re contrasting “prose” with a specific kind of verse, namely “free verse,” which essentially rejects many of the above-listed, somewhat superficial qualities that many people attach categorically to verse (which, as I say, is called by most people, for convenience’s sake, poetry). So such stuff as stanzas, meter, rhyme-schemes, etc. (none of which is strictly speaking essential to verse, and certainly not to poetry) is ENTIRELY eliminated, and (theoretically) it’s still possible that what remains, though entirely devoid of virtually all the normal descriptors of verse, is so dead-on perceptive, truthful, honest, (etc.) that it still qualifies as “poetry.”
Theoretically.
In practice (and IMO), very few writers have the ability to make much magic without using the tools of formal verse, but I have seen some “free verse” of amazing power. I have also seen a whole lot of total crap that is no better than the crap it would have been if presented without the line-breaks that lend it the cloak of verse.
Roses are red,
Violets are blue,
I write poetry
That doesn’t rhyme.
So “poetry” is an honorific applied ex post facto (I guess). If I decide to write, I can choose to write verse or prose, whether it counts as poetry is determined by the resulting quality of work. Am I reading you correctly?
It’s starting to grow on me, too 
OK, I agree with this - I was only thinking of a particular type of poetry when I posted what I did. I believe that the ‘best words in the best order’ idea of poetry leads to an idealised form of poetry which uses fewer words than in prose, and where each word is more considered for its shades of meaning. For me, poetry that takes on many meanings because of its vagueness isn’t particularly effective, and that’s what I meant by ‘precise’ - not that the words immediately give up their meaning, but that they are used only with a great deal of thought behind all of their meanings.
Then there’s so-called “found poetry.” If you Google the term, you’ll find a lot of it. The idea is that you can take something written as prose, and look at it as poetry, and it becomes poetry. Some people take it more seriously than others. From that point of view, it’s poetry if someone says it is.
Okay. That makes more sense. Thanks for clearing that up for me. (I’ve heard that before and it has always had me confused.)
Yeah, JS Africanus, that’s about it (though the word “poetry” is usually applied to everything from Ezra Pound to Hallmark greetings)–Robert Frost once told a youngster describing himself at Frost’s doorstep as a poet, “That’s a praise-word. I’d wait until someone else called me that before using it myself” (or words to that effect.) I’d say “I’m trying to write poetry,” or “I’ve had some poems published” easily enough (because those phrases imply intent or the judgment of others) but rarely do I say "I’m a poet.’ In much the same vein, anyone can say accurately “I like shooting hoops,” but to claim “I’m a great basketball player” requires some serious objective affirmation, no? There’s quite a difference there.
Prose can say too liittle, with too much.
Poetry can say too much, with too little.
With prose you can write a structurally sound sentences, with proper words in proper places, that say ‘nonsense’ to us.
With you can write
poetry
that somehow
non
with improper words
sense,
in improper places,
'structur
becomes
ally sound'
to us.
Ahhh!!! This vB is from Porlock!! There were specific spacing that alas have been truncated.
There are some people who proposition that many works written in prose style can be considered poetry. But then the problem with that view lies with those that wish to avoid poetry all together.
Best line I have ever read here. Just wanted to let you know.