In savage and nomadic times sound sleep being an element of danger, the security which required men to sleep on their arms demanded also that they should sleep as it were with one eye open. Thus there might have arisen both the intense vividness which demons acquired by blending subjective and objective impressions, and the curious inability, so frequent among barbarians and not unknown among the men civilised, to distinguish dream from fact. The habit of day-dreaming seems, indeed, more general than is usually supposed. Dreams haunt all the region of our intellectual twilight,--the borderland of mystery, where rise the sources of the occult and the mystical which environ our lives. The daily terrors of barbarous life avail to haunt the nerves of civilised people, now many generations after they have passed away, with special and irrational shudders at certain objects or noises: how then must they have haunted the dreams of humanity when, like the daughter of Nathan the Wise, rescued from flames, it passed the intervals of strife With nerves unstrung through fear, And fire and flame in all she sees or fancies; Her soul awake in sleep, asleep when wide awake? Among the sources of demoniac beliefs few indeed are more prolific than Dreams. 'The witchcraft of sleep,' says Emerson, 'divides with truth the empire of our lives. This soft enchantress visits two children lying locked in each other's arms, and carries them asunder by wide spans of land and sea, wide intervals of time. 'Tis superfluous to think of the dreams of multitudes; the astonishment remains that one should dream; that we should resign so quietly this deifying reason and become the theatre of delusions, shows, wherein time, space, persons, cities, animals, should dance before us in merry and mad confusion, a delicate creation outdoing the prime and flower of actual nature, antic comedy alternating with horrid spectres. Or we seem busied for hours and days in peregrinations over seas and lands, in earnest dialogues, strenuous actions for nothings and absurdities, cheated by spectral jokes, and waking suddenly with ghostly laughter, to be rebuked by the cold lonely silent midnight, and to rake with confusion in memory among the gibbering nonsense to find the motive of this contemptible cachinnation.' [169]