I do not believe that it is possible to name a set of requirements for poetry. In several languages, mere parallelism of thought is one defining feature — e.g., the Bible. In English the variations of form and substance, from Piers Plowman to Robert Bridges and from Walt Whitman to G. M. Hopkins and William Carlos Williams are enough to defy definition.
Coleridge brushed aside the distinction between verse and prose in order to be able to find poetry wherever his sense of it dictated, and I think that his way is the one followed by most readers as individuals. One says “this is poetry” and another says “not on your life” about the same words. If art is a contrived extension of life, as I believe, this dissensus is to be expected. One person says “life is good” or “life is a vale of soul-making,” and another says “life is bad,”, “life is a tale told by an idiot, signifying nothing.”
— Jacques Barzun, “Reader’s Forum”, Aristos: The Journal of Esthetics, December 1988.