Another matter which requires elucidation here is the place which the conception of God holds in Plato's system. He frequently uses the word God both in the singular and the plural, and seems to slip with remarkable ease from the monotheistic to the polytheistic manner of speaking. In addition to the many gods, we have frequent reference to the one supreme Creator, controller, and ruler of the world, who is further conceived as a Being providentially watching over the lives of men. But in what relation does this supreme God stand to the Ideas, and especially to the Idea of the Good? If God is separate from the highest Idea, then, as Zeller points out, [Footnote 13] only three relations are possible, all of which are {203} equally objectionable. Firstly, God may be the cause or ground of the Idea of the Good. But this destroys the substantiality of the Idea, and indeed, destroys Plato's whole system. The very essence of his philosophy is that the Idea is the ultimate reality, which is self-existent, and owes its being to nothing else. But this theory makes it a mere creature of God, dependent on Him for its existence. Secondly, God may owe His being to the Idea. The Idea may be the ground of God's existence as it is the ground of all else in the universe. But this theory does violence to the idea of God, turning Him into a mere derivative existence, and, in fact, into an appearance. Thirdly, God and the Idea may be co-ordinate in the system as equally primordial independent ultimate realities. But this means that Plato has given two mutually inconsistent accounts of the ultimate reality, or, if not, that his system is a hopeless dualism. As none of these theories can be maintained, it must be supposed that God is identical with the Idea of the Good, and we find certain expressions in the "Philebus" which seem clearly to assert this. But in that case God is not a personal God at all, since the Idea is not a person. The word God, if used in this way, is merely a figurative term for the Idea. And this is the most probable theory, if we reflect that there is in fact no room for a personal God in a system which places all reality in the Idea, and that to introduce such a conception threatens to break up the whole system. Plato probably found it useful to take the popular conceptions about the personality of God or the gods and use them, in mythical fashion, to express his Ideas. Those parts of Plato which speak of God, and the governance of God, {204} are to be interpreted on the same principles as the other Platonic myths. [Footnote 13: _Plato and the Older Academy_, chap. vi.]