In this passage we see Jove invested with the glory of defeating a great demon; but we also recognise the demon still under the protection of Fate. Destiny must bear that burthen. So was it said in the Apocalypse Satan should be loosed after being bound in the Pit a thousand years; and so Mohammed declared Gog and Magog should break loose with terror and destruction from the mountain-prison in which Allah had cast them. The destructive Principle had its 'share' as well as the creative and preservative Principles, and could not be permanently deprived of it. Gradually the Fates of various regions and names were identified with the deities, whose interests, gardens, or treasures they guarded; and when some of these deities were degraded their retainers were still more degraded, while in other cases deities were enabled to maintain fair fame by fables of their being betrayed and their good intentions frustrated by such subordinates. Thus we find a certain notion of technical and official power investing such figures as Satan, Ahriman, Iblis, and the Dragon, as if the upper gods could not disown or reverse altogether the bad deeds done by these commissioners. But the large though limited degree of control necessarily claimed for the greatest and best gods had to be represented theologically. Hence there was devised a system of Commutation. The Demon or Dragon, though abusing his power, could not have it violently withdrawn, but might be compelled to accept some sacrifice in lieu of the precise object sought by his voracity. These substitutions are found in every theological system, and to apply them to individuals constitutes the raison d'être of every priesthood. In the progress towards civilisation the substitutes diminish in value, and finally they become merely nominal and ceremonial,--an effigy of a man instead of the man, or wine instead of blood. At first the commutation was often in the substitution of persons of lower for others of higher rank, as when slaves or wives were, or are, sacrificed to assure paradise to the master or husband. Thus, Death is allowed to take Alcestis instead of Admetus. A higher degree of civilisation substitutes animals for human victims. In keeping with this is the legend of Christ's sending demons out of two men into a herd of swine: [255] which, again, is referable to the same class of ideas as the legend that followed concerning Jesus himself as a vicarious offering; mankind in this case being the herd, as compared with the son of a god, and the transfer of the Satanic power from the human race to himself, for even a little time, being accepted in theology as an equivalent, on account of the divine dignity of the being who descended into hell. It was some time, however, before theology worked out this theory as it now stands, the candid fathers having rejoiced in the belief that the contract for commutation on its face implied that Christ was to remain for ever in hell, Satan being outwitted in this.