The relatively rich store of memorials left by the Egyptian religions yields us hardly any more direct light on the growth of religious rationalism than do those of Mesopotamia, though it supplies much fuller proof that such a growth took place. All that is clear is that the comparison and competition of henotheistic cults there as elsewhere led to a measure of relative skepticism, which took doctrinal shape in a loose monism or pantheism. The language is often monotheistic, but never, in the early period, is polytheism excluded; on the contrary, it is affirmed in the same breath. [230] The alternate ascendancy of different dynasties, with different Gods, forced on the process, which included, as in Babylon, a priestly grouping of deities in families and triads [231]--the latter arrangement, indeed, being only a return to a primitive African conception. [232] It involved further a syncretism or a combining of various Gods into one, [233] and also an esoteric explanation of the God-myths as symbolical of natural processes, or else of mystical ideas. [234] There are even evidences of quasi-atheism in the shape of materialistic hymns on Lucretian lines. [235] At the beginning of the New Kingdom (1500 B.C.) it had been fully established for all the priesthoods that the Sun-God was the one real God, and that it was he who was worshipped in all the others. [236] He in turn was conceived as a pervading spiritual force, of anthropomorphic character and strong moral bias. [237] This seems to have been by way of a purification of one pre-eminent compound deity, Amen-Ra, to begin with, whose model was followed in other cults. [238] "Theocracies of this kind could not have been formed unconsciously. Men knew perfectly well that they were taking a great step in advance of their fathers." [239] There had occurred, in short, among the educated and priestly class a considerable development, going on through many centuries, alike in philosophical and in ethical thought; the ethics of the Egyptian "Book of the Dead" being quite as altruistic as those of any portion of the much later Christian Gospels. [240] Such a development could arise only in long periods of peace and law-abiding life; though it is found to be accelerated after the Persian conquest, which would force upon the Egyptian priesthood new comparisons and accommodations. [241] And yet all this was done "without ever sacrificing the least particle of the beliefs of the past." [242] The popular polytheism, resting on absolute ignorance, was indestructible; and the most philosophic priests seem never to have dreamt of unsettling it, though, as we shall see, a masterful king did.