What's the diffrence between poetry and delineated prose?

[UselessBlueprint]

Jumping back a bit, because I've been at work most of the day unable to reply. I'd again like to remark that I believe in quantitative definitions. Something must be quantified to be categorized.Take for example the difference between detonation and deflagration. Detonation occurs when the flame front travels at or greater than the speed of sound. Deflagration occurs when the flame front travels below the sonic velocity. [ref]
Again, the defining lines you choose will depend on what you call a poem. If I were to write some prose, but call it a poem, how would you disagree with me? In fact, how would you know that everything I've written here is not a poem itself?
Be critical. Ask questions of yourself, pursue the answers. When we have differing views on what is a poem and what is not, we will have differing views on the line that "divides" prose from poetry, if such a line exists. If you only believe in the collective consensus of the literary world you subscribe to, I do hope your beliefs are never challenged by a skilled writer.

I'm not sure I've ever heard prose and poetry being described as polar opposites.  I have, but that's a moot point perhaps, as long as you can accept something is both poetry and prose.
Rowens has suggested a relationship to the two which cannot separated, and has suggested concepts which differentiate between the two - in his opinion. Personally, I battle with your suggestion that prose can be poetry and vice versa.  I see no dispute with the suggestion prose can be poetic, perhaps even poetry can be prosaic (though that would have to be explained if anyone wants to take up the challenge), but I can't see a writing being both. I'd like to know the difference between something that is poetic and something that is poetry, in that case.

Prose doesn't make the reader search for veiled meaning? It can. In my original post, I said that it may. But for me to consider it prose -- see duke's etymology -- it must reach an objective in a straightforward manner. Not every objective must be met this way, but at least one.
"Au contraire," I would shout, if I knew what meant lol. Prose can use symbolism, allegory, analogy, etc and fine prose often does, IMO. I never said otherwise.
One of my favourite authors created an entire world based on [lightly] hidden meaning, and as such became one of the most endeared writers of our generation. (Sorry to digress). Don't want it so deeply hidden - in either poetry or prose - the reader never finds it. Are you arguing these are tools one can use in poetry? Certainly.  One might even argue meaning can be hidden more deeply in a poem which is "compressed" because a reader has more time to be contemplative, as there might not be too much material to parse.
But does all poetry use hidden levels of meaning? Not in my opinion. Hidden is not the same as compressed.
Are all poems 'compressed?  Again, I'll mention epic poetry. Nothing finer than to be forced to  wade through the adventure of Odysseus *snort*.  I spent seven years in my teens thoroughly enjoying my Latin class, at least two good years of it were reading Catullus and Virgil. I hope the Aeneid counts as an epic.
Compression is another tool, but I don't believe it [alone] is a definitive one.

I turn the question to you. What do you think defines a work of prose or poetry? What have you observed -- on your own reading, not from what we've all replied -- marks the difference between poetry and prose? The question you asked suggests you haven't marked a difference. Yet, if you think prose can be poetic but not poetry, tell me why. And if you think that poetry can be prosaic but not prose, tell me how.