Literature Assignment

For this discussion I want bring in an old literary theory - M.H. Abram's The Mirror and the Lamp. Abrams posits that before the Romantic movement in England literature existed a mirror to reflect the realities of life, whereas the Romantic poets (i.e. Wordsworth, Shelley and the like) wrote from the point of view that literature served as a lamp to illuminate the darkness of the world and the human condition, that the poet's job was to enlighten humanity.

The question I want to ask is this:  Which is more correct?  What is the role of poetry in society?  Is it to reflect the realities of the world back to us so we can understand them or is it to light our way through the dark world that being alive, to enlighten us?  Which works better and can you think of any poems that doe either/or or both?