text:  If we add to this the powerful materials of lightness and darkness over which the artist has complete dominion to vary and dispose them as he pleases--to diminish or increase them as will best suit his purpose and correspond to the general idea of his work; a landscape thus conducted under the influence of a poetical mind will have the same superiority over the more ordinary and common views as Milton's "Allegro" and "Penseroso" have over a cold prosaic narration or description; and such a picture would make a more forcible impression on the mind than the real scenes were they presented before us