It must be admitted, however, that, owing to its extreme flexibility, this religion was easily adapted to the various centers to which it was transferred, and that it enjoyed the valuable advantage of being always in perfect harmony with the prevailing philosophy. Moreover, the syncretic tendencies of Egypt responded admirably to those that began to obtain at Rome. At a very early period henotheistic theories had been favorably received in sacerdotal circles, and while crediting the god of their own temple with supremacy, the priests admitted that he might have a number of different personalities, under which he was worshiped simultaneously. In this way the unity of the supreme being was affirmed for the thinkers, and polytheism with its {89} intangible traditions maintained for the masses. In the same manner Isis and Osiris had absorbed several local divinities under the Pharaohs, and had assumed a complex character that was capable of indefinite extension. The same process continued under the Ptolemies when the religion of Egypt came into contact with Greece. Isis was identified simultaneously with Demeter, Aphrodite, Hera, Semele, Io, Tyche, and others. She was considered the queen of heaven and hell, of earth and sea. She was "the past, the present and the future,"[42] "nature the mother of things, the mistress of the elements, born at the beginning of the centuries."[43] She had numberless names, an infinity of different aspects and an inexhaustible treasure of virtues. In short, she became a pantheistic power that was everything in one, _una quae est omnia_.[44] The authority of Serapis was no less exalted, and his field no less extensive. He also was regarded as a universal god of whom men liked to say that he was "unique." ([Greek: Heis Zeus Sarapis]) In him all energies were centered, although the functions of Zeus, of Pluto or of Helios were especially ascribed to him. For many centuries Osiris had been worshiped at Abydos both as author of fecundity and lord of the underworld,[45] and this double character early caused him to be identified with the sun, which fertilizes the earth during its diurnal course and travels through the subterranean realms at night. Thus the conception of this nature divinity, that had already prevailed along the Nile, accorded without difficulty with the solar pantheism that was the last form of Roman paganism. This theological system, which did not gain the upper hand in the Occident until the {90} second century of our era, was not brought in by Egypt. It did not have the exclusive predominance there that it had held under the empire, and even in Plutarch's time it was only one creed among many.[46] The deciding influence in this matter was exercised by the Syrian Baals and the Chaldean astrology.