20. In the Greek system of theology we find in the first place a number of deities of varying importance and power, whose special functions are defined with some distinctness; and then, below these, an innumerable band of spirits, the souls of the departed--probably the relics of an earlier pure ancestor-worship--who still interest themselves in the inhabitants of this world. These [Greek: daimones] were certainly accredited with supernatural power, and were not of necessity either good or evil in their influence or action. It was to this second class that foreign deities were assimilated. They found it impossible, however, to retain even this humble position. The ceremonies of their worship, and the language in which those ceremonies were performed, were strange to the inhabitants of the land in which the acclimatization was attempted; and the incomprehensible is first suspected, then loathed. It is not surprising, then, that the new-comers soon fell into the ranks of purely evil spirits, and that those who persisted in exercising their rites were stigmatized as devil-worshippers, or magicians. But in process of time this polytheistic system became pre-eminently unsatisfactory to the thoughtful men whom Greece produced in such numbers. The tendency towards monotheism which is usually associated with the name of Plato is hinted at in the writings of other philosophers who were his predecessors. The effect of this revolution was to recognize one Supreme Being, the First Cause, and to subordinate to him all the other deities of the ancient and popular theology--to co-ordinate them, in fact, with the older class of daemons; the first step in the descent to the lowest category of all. 21. The history of the neo-Platonic belief is one of elaboration upon these ideas. The conception of the Supreme Being was complicated in a manner closely resembling the idea of the Christian Trinity, and all the subordinate daemons were classified into good and evil geniuses. Thus, a theoretically monotheistic system was established, with a tremendous hierarchy of inferior spirits, who frequently bore the names of the ancient gods and goddesses of Egypt, Greece, and Rome, strikingly resembling that of Roman Catholicism. The subordinate daemons were not at first recognized as entitled to any religious rites; but in the course of time, by the inevitable operation of the first principle just enunciated, a form of theurgy sprang up with the object of attracting the kindly help and patronage of the good spirits, and was tolerated; and attempts were made to hold intercourse with the evil spirits, which were, as far as possible suppressed and discountenanced.