Among the recognizable signs of normal progress in the ordinary Aztec religion were (1) the general recognition of the Sun as the God really worshipped in all the temples of the deities with special names; [325] (2) the substitution in some cults of baked bread-images for a crucified human victim. The question arises whether the Aztecs, but for their overwhelming priesthood, might conceivably have risen above their system of human sacrifices, as the Aryan Hindus had done in an earlier age. Their material civilization, which carried on that of the kindred Toltecs, was at several points superior to that which the Spaniards put in its place; and their priesthood, being a leisured and wealthy class, might have developed intellectually as did the Brahmans, [326] if its economic basis had been changed. But only a conquest or other great political convulsion could conceivably have overturned the vast cultus of human sacrifice, which overran all life, and cherished war as a means of procuring victims. In the kindred State of Tezcuco, civilization seems to have gone further than in Aztec Anahuac; and about the middle of the fifteenth century one Tezcucan king, the conqueror Netzahualcoyotl, who has left writings in both prose and verse, is seen attaining to something like a philosophic creed, of a monotheistic stamp. [327] He is said to have rejected all idol-worship, and erected, as aforesaid, an altar "to the Unknown God," [328] forbidding all sacrifices of blood in that worship. But among the Tezcucans these never ceased; three hundred slaves were sacrificed at the obsequies of the conqueror's son, Netzahualpilli; and the Aztec influence over the superior civilization was finally complete. In Peru, again, we find civilization advancing in respect of the innovation of substituting statuettes for wives and slaves in the tombs of the rich; and we have already noted [329] the remarkable records of the avowed unbelief of several Incas in the divinity of the nationally worshipped Sun. For the rest, there was the dubious quasi-monotheistic cult of the Creator-God, Pachacamac, concerning whom every fresh discussion raises fresh doubt. [330]