In the infancy of the world, when natural phenomena were ill-understood, expressions which to us are poetical were of a real significance. When we speak of thunder rolling, we use an expression which conveys no further idea than a certain likeness observed between the detonations and the roll of a vehicle; but to the uninstructed mind it was more. The primæval savage knew not what caused thunder, and tracing the resemblance between it and the sound of wheels, he at once concluded that the chariot of the gods was going abroad, or that the celestial spirits were enjoying a game of bowls.
We speak of fleecy clouds, because they appear to us soft and light as wool, but the first men tracing the same resemblance, believed the light vapours to be flocks of heavenly sheep. Or we say that the clouds are flying: the savage used the same expression, as he looked up at the mackerel sky, and saw in it flights of swans coursing over the heavenly lake. Once more, we creep nearer to the winter fire, shivering at the wind, which we remark is howling around the house, and yet we do not suppose that the wind has a voice. The wild primæval men thought that it had, and because dogs and wolves howl, and the wind howled, and because they had seen dogs and wolves, they concluded that the storm-wind was a night-hound, or a monstrous wolf, racing over the country in the darkness of the winter night, ravening for prey.
Along with the rise of this system of explaining the operations of nature by analogies in the bestial world, another conclusion forced itself on the untaught mind. The flocks which strayed in heaven were no earthly sheep, but were the property of spiritual beings, and were themselves perhaps spiritual; the swans which flew aloft, far above the topmost peak of the Himalaya, were no ordinary swans, but were divine and heavenly. The wolf which howled so wildly in the long winter night, the hounds, whose bay sounded so. dismally through the shaking black forest, were no mundane wolves and hounds, but issued from the home of a divine hunter, and were themselves wondrous, supernatural beings of godlike race.
And so, the clouds having become swans, the swan-clouds were next believed to be divine beings, valkyries, apsaras, and the like, seen by mortals in their feather-dresses, but appearing among the gods as damsels. The storm-wind having been supposed to be a wolf, next was taken to be a tempestuous god, who delighted to hunt on earth in lupine form.