but natural that the principle, 'a life for a life,' which has been borrowed from the institution of blood-revenge and has been applied to the punishment for murder, should be developed into a scale of physical punishment representing the more general principle 'like for like.' He who has destroyed the eye of another, must lose his own eye; whoever has disabled another's arm, must have his arm cut off, etc. Other injuries then came to be similarly punished, even those of a moral character to which the principle "eye for eye, tooth for tooth" is not directly applicable. The hand which has been implicated in an act of sacrilege, such as the commission of perjury, is to be cut off; the tongue which has slandered, must be torn out. Originally, the death penalty was employed all too freely. Hence this substitution of a physical punishment which spared the life of the offender was doubtless in the direction of moderation. But, since this substitution gave rise to cruelties that resulted in the infliction of various sorts of death penalties, preceded and accompanied by tortures, its original effect became reversed, just as in the case of imprisonment. Moreover, the two forms of punishment--imprisonment and death--and the degree to which these were carried to excess differed according to civilization and race. The _jus talionis_ was the older principle of punishment. It is more closely bound up with man's natural impulse for retaliation, and therefore recurs even within humane civilizations, sometimes merely in suggestions but sometimes in occasional relapses which are of a more serious sort and are due to the passion for revenge. In fundamental contrast with the Mosaic law, Christianity repudiated the requital of like with like. Perhaps it was the fear of violating its own principle that led it, in its later development, to seek in the cruelties of severe prison penalties a substitute for the repressed impulse to revenge which comes to expression in coarser conceptions of justice. Nevertheless, this substitution was superior to the inflexible severity of the _jus talionis_ in that it more effectively enabled milder customs to influence the judicial conscience.