In whatever way human sacrifice originated, it was obviously destined, with the advance of civilization, to undergo modification. Not only would the growing moral sense of mankind learn to hold it a dark and terrible thing, but also to go on killing the leading man of the tribe, the king-priest, would have its obvious practical inconveniences. At first, indeed, these would not be great. The king-priest would be little more than a rain-maker, a _rex sacrorum_, and one man might perform the ceremonial observances as well as another. But as time went on, and the tribe settled down to a comparatively civilized life, the serious functions of its leader would increase. He would become the arbiter of justice, the adviser in debate; above all, when war grew into importance, the captain in battle. And to spare and replace, year by year, the wisest councillor and the bravest warrior would grow into an intolerable burden. Under some such circumstances, one can hardly doubt, a process of substitution set in. Somebody had to die for the king. At first, perhaps, the substitute was an inferior member of the king’s own house, or even an ordinary tribesman, chosen by lot. But the process, once begun, was sure to continue, and presently it was sufficient if a life of little value, that of a prisoner, a slave, a criminal, a stranger within the gates, was sacrificed[445]. The common belief in madness or imbecility as a sign of divine possession may perhaps have contributed to make the village fool or natural seem a particularly suitable victim. But to the very end of Teutonic and Keltic heathenism, the sense that the substitute was, after all, only a substitute can be traced. In times of great stress or danger, indeed, the king might still be called upon to suffer in person[446]. And always a certain pretence that the victim was the king was kept up. Even though a slave or criminal, he was for a few days preceding the sacrifice treated royally. He was a temporary king, was richly dressed and feasted, had a crown set on his head, and was permitted to hold revel with his fellows. The farce was played out in the sight of men and gods[447]. Ultimately, of course, the natural growth of the sanctity of human life in a progressive people, or in an unprogressive people the pressure of outside ideals[448], forbids the sacrifice of a man at all. Perhaps the temporary king is still chosen, and even some symbolic mimicked slaying of him takes place; but actually he does not die. An animal takes his place upon the altar; or more strictly speaking, an animal remains the last victim, as it had been the first, and in myth is regarded as a substitute for the human victim which for a time had shared its fate. Of such a myth the legends of Abraham and Isaac and of Iphigeneia at Aulis are the classical examples.