What exactly is poetry and what makes a good poem?

Peter Davison, poetry editor, The Atlantic Monthly:

Poetry should make contact with every part of you, with the mind, with the senses, especially with the ear. [US Poet Laureate Robert] Pinsky likes to say that poetry is built on a column of breath, and I agree with him absolutely. Poetry is composing for the breath. The breath is the most intimate aspect of our existence. It is what connects us to the biosphere. It is what makes our voice operate. It is what makes oxygen go through our bodies, and it is what gives us rhyme, which is why poetry existed at all.

Poetry was a mnemonic device to enable people to remember their prayers. Or even the inventories of the warehouses in ancient Babylon. That's why we wrote in rhythm and meter, so that we could remember what we had thought or what we had compiled. The whole connection of sense to mind to memory to rhythm to emotion is why one gets involved.

Alice Quinn, poetry editor, The New Yorker:

A poem is provoked by an emotion. But the emotion probably isn't fulfilled until the poem is made. I think when the design of a poem seems ideal and organic, when the feeling is strong and the language is fresh, it's going to strike us as truly resolved and original.

You know, Elizabeth Bishop said that she could tell when she read a great poem because for the next 24 hours she saw the world in the light of that poem. As if the poem itself had cast its own emotional tone over everything, and she would feel life under the guidance of that star. Sometimes, after I take a group of poems and send them downstairs to get set into type, on my way home in the subway I'll try to remember which eight poems I put through that day. I can almost always remember them pretty exactly, because if you love a poem, you can summon it up from beginning to end. It has a wonderful first line and it's fulfilled and it's cinched at the end and it has a shape, like a great ballet has a shape or a great piece of music.