Poetry gets made, lips mumble, & the talk about poetry floats around the perimeter.
Literary thought-about-it blends with philosophy, politics, sociology... people proclaim their preferences, allegiances, enthusiasms...
but is there a particular social purpose, role, telos for poetry as poetry? Can this be looked at, without the effort being immediately branded as aesthetical detachment, diffidence, quietism, art-for-art, etc.?
Are you only interested in art as a vehicle for working out your ambitions & frustrations (personal or political)? Or your ideals, even?
The natural pull of what is beautiful tends to send these things (frustrations, ambitions, ideals, ideas) through a sort of shift-changer, a distortion-pedal...
What is beautiful, in relation to what is right? old debate....
A poem has a form (beginning to end). & the form contains a variable degree of moral weight or impact.
But getting back to the question of a unique social role for poetry as poetry... it seems pretty obvious that there is no single or homogenized purpose here. There are different & shifting degrees of social or cultural engagement. The same can be said for the other arts. They are put to differing applications, based on various motives & aims.
What I would emphasize (as often before) is that poetry is a unique verbal mode - one which combines art (aesthetic values), performance (embodiment), & personal presence. As such it is akin to drama. But more intensively than drama, poetry displays (in dramatic form) a fusion of consciousness-personality-language. With drama - as with prose discourse generally - there is an aspect of alienation or distancing, when the text or the composition intrudes between the one who speaks and the one who listens. A poem is a form of soliloquy, of recitation, and a poetic text is the transcription of same.
So what are the consequences of this special verbal form for the form's social role?
If we look at this phenomenon through a kind of amateur or informal philosophical lens, we might see some implications - some implied arguments, which this special form of verbal address makes, about the nature of reality & experience. I guess Heidegger & many another not-so-amateur philosopher (back to Plato) have had much to say about all this.
What strikes me is how the special filter or form through which poetry sends language offers a sort of challenge/critique to prose discourse. Language is embedded firmly in the circle of human presence and consciousness. Even its famous "impersonality" is the effect of an artistic (& personal) ascesis, for the sake of an achieved form which itself will be imprinted with creative consciousness.
This was an element of the stand taken by the Romantic poets, in response to Enlightenment rationalism and the rise of science. If knowledge is related to Becoming (the mind seeking to know, the hand seeking to control), then perhaps art is related to Being (the intuition of wholeness or completion, despite present imperfections - Keats's "negative capability", essentially). And I suppose the conjunction of Romanticism and medievalism is no accident, since the medieval outlook was based on a confidence in an ultimate (sacred) equilibrium, between knowledge & experience, Becoming & Being (a worldview whose static - or perhaps I should say a-historical, mythical - aspect, the new sciences came forward to challenge).
Victorian, modern & postmodern (western) science & philosophy have, for the most part anyway, served to corrode the ground beneath the Romantic vision (which was difficult & shaky terrain to begin with). Yet the actual pragmatics of poetic making can't simply be identified with a philosophical attitude or cultural zeitgeist (Romantic, Modern, Postmodern...). Poetry's fusion of art, consciousness, personhood & performance has in it something older, something archaic and uncanny. It is, in itself (like all art, going back to the cave painters) an argument for, a statement of, Being. The philosophers & theorists who deny the reality of Being, must also (& do) deny the order, the equilibrium, of art; and poetry is the art of language.
In a sense Keats' notion of "negative capability" has never carried more intellectual weight than it does right now, in this era - since now the ontological status of everything except that "unknowing" equilibrium, which he ascribed to poets, is called into question. Hence poetry has had many 20th-cent. false friends among the philosophers, from Heidegger to Derrida; notions of poetry's unique status in a cosmos of irreality always end up condescending to it in the end (since language, too, is irreal).
So poetry, then, continues to present language in its ancient musical-dramatic mode, by way of its own play-realm of art, beauty, equilibrium, wholeness. As such it offers a challenge not only to postmodern philosophy, but to philosophy in general - to prose discourse of every kind. The intense presence, the actuality, of the poetic performance belies depersonalized abstractions of every persuasion. Plato recognized the challenge, & acted accordingly (exiling poets from his ideal state).
And if poets want to explore the peculiarities, the special characteristics, of the social role of their vocation, I would think they would do well to ponder these peculiar, pragmatic characteristics of the mode itself - how, through art, Being is represented - and defined, delimited - by way of living (& expressively-performing) persons. Here is where poetry is itself : not politics, not philosophy, not any other kind of talk.