The book which put Stevenson's name in the mouth of the ' man in the street,' lifted him at a single bound to a place among men of the time and, by the still greater sensation which it created in America, led to the large income which soon afterwards he drew from the United States. The ear of a great public to whom his earlier writings were unknown was captured by this intense picture of the elements of good and evil in man's nature. It was hailed from pulpits and in the religious press as a great moral parable; though its moral quality, on close analysis, is seen to be more an illusion, due to the art of its writing, than the essence of the fable. Reduced to its simplest formula Jekyll and Hyde is a cry of terror at the potency for evil latent in the human soul. Such moral force as it has depends upon its assault on the nerves, not on its appeal to the heart. If not thus interpreted by the preachers of the time, it yet served the purpose of moving their hearers by the spectacle of the evil partner in the human ego, indulged in a moment ' when virtue slumbered,' coming in the end to destroy the good.