Of course the antecedents of the arch-fiend himself could not fail to be the subject of curious inquiry in the time when his existence was no matter of doubt. The old theologians scraped together enough material about him from the sacred books of the Jews and Christians to construct an elaborate biography of him; but in this they would seem to have explained too much in certain directions and not enough in others, thus provoking a reaction which ultimately discredited their painful research. Their genealogy of him was carried farther back than they intended or desired, for the popular notions credited him with both a mother and grandmother. Their theory of his fall from heaven gave rise to the droll conception of his lameness and to the legends of which the "devil on two sticks" is a type. Their infusion of foreign element into his nature aided his pictorial presentment in motley form and garb, as seen in the old miracle-plays. To Vedic descriptions of Vritra's darkness may perchance be traced his murkiness and blackness; to Greek satyr and German forest-sprite his goat-like body, his horns, his cloven hoofs, his tail; to Thor his red beard; to dwarfs and goblins his red cloak and nodding plume; to theories of transformation of men and spirits into animals his manifold metamorphoses, as black cat, wolf, hellhound, and the like.
But his description was his doom; it was by a natural sequence that the legends of mediæval times present him, not, with the Scotch theologians, as a scholar and a swindler, disguising himself as a parson, but as gullible and stupid, as over-reaching himself and as befooled by mortals. And, like the Trolls of Scandinavian folk-lore who burst at sunrise, it needed only the full light thrown upon his origin and development by the researches of comparative mythologists to dissipate this creation of man's fears and fancies into the vaporous atmosphere where he had his birth.
The cogency of the evidence concerning the development of belief in Satan out of light-and-darkness myths is generally admitted, but it is of a kind that must not be pushed too far. For the phases of Nature are manifold; manifold also is the life of man; and we must not lend a too willing ear to theories which refer the crude explanations of an unscientific age, when the whole universe is Wonderland, to one source. _Cave hominem unius libri_, says the adage, and we may apply it, not only to the man of one book, but also to the man of one idea, in whom the sense of proportion is lacking, and who sees only that for which he looks. Here such caution is introduced as needful of exercise against the comparative mythologists who, not content with showing--as abundant evidence warrants--that myth has its germs in the investment of the powers of nature with personal life and consciousness, contend that the great epics of our own and kindred races are, from their broadest features to minutest detail, but nature-myths obscured and transformed.