That man's best works should be such bungling imitations of Nature's infinite perfection, matters not much; but that he should make himself an imitation, this is the fact which Nature moans over, and deprecates beseechingly. Be spontaneous, be truthful, be free, and thus be individuals! is the song she sings through warbling birds, and whispering pines, and roaring waves, and screeching winds.

Letters from New York,vol. 1, letter 38 - Letters from New York (1843)