http://flavorwire.com/413949/20-poets-on-the-meaning-of-poetry/2
There are a few more choice snippets from Shelley’s 1821 essay, A Defence of Poetry, that articulated the essence of poetry:
“Poetry is indeed something divine. It is at once the centre and circumference of knowledge; it is that which comprehends all science, and that to which all science must be referred. It is at the same time the root and blossom of all other systems of thought; it is that from which all spring, and that which adorns all; and that which, if blighted, denies the fruit and the seed, and withholds from the barren world the nourishment and the succession of the scions of the tree of life. It is the perfect and consummate surface and bloom of all things; it is as the odor and the color of the rose to the texture of the elements which compose it, as the form and splendor of unfaded beauty to the secrets of anatomy and corruption.”
“Poetry is the record of the best and happiest moments of the happiest and best minds.”
“Poetry, in a general sense, may be defined to be ‘the expression of the imagination’: and poetry is connate with the origin of man.”
“Poetry is a mirror which makes beautiful that which is distorted.”
“Poetry is a sword of lightning, ever unsheathed, which consumes the scabbard that would contain it.”
“All high poetry is infinite; it is as the first acorn, which contained all oaks potentially.”


