This explains why it is that, in all countries, the power of the state, in a period of transition towards a higher civilization, has endeavored to render slavery milder. Great credit is due the Church in this regard. It soon extinguished slavery entirely in Scandinavia,(427) and in portions of Europe it abolished at least the sale of prisoners to foreign countries.(428) The _Concilium Agatheuse_, in the year 506, decreed that serfs should not be killed by their masters at pleasure,(429) but that they should be brought before a tribunal of justice. (The manorial tribunals of more recent times.) Moreover, the numberless holidays of the church operated greatly in favor of the bondmen. Pope Alexander III. recommended their gradual emancipation.(430) One of the principal steps in the way of progress was made when they could no longer be sold singly, but only with the village or on the estate to which they belonged.(431) The feudal aristocracy improved the condition of the bondmen by reducing a great number of freemen to their level.(432) This could not be effected without a real amelioration of slavery; and, later, when the feudal aristocracy declined, the older serfs were, with those who had been formerly free, raised from their abject condition. The sense of chivalry would not permit a lord to be served by a bondman. The old adage “the serf lives to serve and serves to live,” by degrees, lost its force. Serfs were required to perform certain tasks on the lands of their master and to pay him a certain quantity of the produce of their own. Heriots (_mortuarium_), which became usual from the 8th century (_J. Grimm_), may be considered evidence that even bondmen were permitted to acquire and hold property in their own right. Thus was one of the chief disadvantages of slavery, in an economic sense, removed.(433) It may be affirmed, as characteristic of the aristocracy of feudal times, that they treated those, who like the serfs were entirely at their mercy, with much more consideration than those who were free, and, although dependent on them, had certain rights guaranteed by contract. The absolute monarchy found in nearly all nations, at the opening of modern times, was forced by its struggle with the mediæval aristocracy to favor the emancipation of the serfs and of the lower classes. Even in Russia, Iwan III. (1462-1505) seems to have restored to the peasantry the right of migration, of which they had been deprived by the invasion of the Mongols, nor did they lose it again until the great troubles at the beginning of the seventeenth century, which gave the ruling power to the nobility.(434) Where civilization has reached its highest development, the irresistible power of public opinion, governed by the ideas of the universal brotherhood of man and of democratic equality, causes the abolition of all irredeemable and of all hereditary relations of servitude.(435)(436)(437) Section LXXIV.