All words, then, belonging to the inner world of the mind, are of the imagination, are originally poetic words. The better, however, any such word is fitted for the needs of humanity, the sooner it loses its poetic aspect by commonness of use. It ceases to be heard as a symbol, and appears only as a sign. Thus thousands of words which were originally poetic words owing their existence to the imagination, lose their vitality, and harden into mummies of prose. Not merely in literature does poetry come first, and prose afterwards, but poetry is the source of all the language that belongs to the inner world, whether it be of passion or of metaphysics, of psychology or of aspiration. No poetry comes by the elevation of prose; but the half of prose comes by the "massing into the common clay" of thousands of winged words, whence, like the lovely shells of by-gone ages, one is occasionally disinterred by some lover of speech, and held up to the light to show the play of colour in its manifold laminations.
[The Imagination: It's Function and Culture]