“But the quality of the imagination is to flow, and not to freeze. The poet did not stop at the color or the form, but read their meaning; neither may he rest in this meaning, but he makes the same objects exponents of his new thought. Here is the difference betwixt the poet and the mystic, that the last nails a symbol to one sense, which was a true sense for a moment, but soon becomes old and false. For all symbols are fluxional; all language is vehicular and transitive, and is good, as ferries and horses are, for conveyance, not as farms and houses are, for homestead.”

from The Poet by Ralph Waldo Emerson