The primary function of poetry, as of all the arts, is to make us more aware of ourselves and the world around us. I do not know if such increased awareness makes us more moral or more efficient;I hope not.
I think it makes us more human, and I am quite certain it makes us more difficult to deceive, which is why, perhaps, all totalitarian theories of the State, from Plato’s downwards, have deeply distrusted the arts. They notice and say too much, and the neighbours start talking.
— W. H. Auden (1938) quoted in James Fenton, Auden at Home, The New York Review of Books, April 27 2000
Edited to add: I don’t share Auden’s certainty that poetry “makes us more difficult to deceive”. It’s an interesting assertion, though, and I’m wondering how one might test it…