It is difficult to separate the mythical and the philosophical elements in this cosmogony of the Timæus, especially difficult to determine how far the historical construction, which gives a succession in time to the acts of creation, is only a formal one, and also how far the affirmation that matter is absolutely a not-being can be harmonized with the general tenor of Plato’s statements. The significance of the world-soul is clearer. Since the soul in the Platonic system is the mean between spirit and body, and as in the same way mathematical relations, in their most universal expression as numbers, are the mean between mere sensuous existence and the pure idea (between the one and the many as Plato expresses it), it would seem clear that the world-soul, construed according to the relation of numbers, must express the relation of the world of ideas to that of sense, in other words, that it denotes the sensible world as a thought represented in the form of material existence. The Platonic view of nature, in opposition to the mechanical attempts to explain it of the earlier philosophers, is entirely teleological, and based upon the conception of the good, or, on the moral idea. Plato conceives the world as the image of the good, as the work of the divine munificence. As it is the image of the perfect it is therefore only one, corresponding to the idea of the single all-embracing substance, for an infinite number of worlds is not to be conceived as actual. For the same reason the world is spherical, after the most perfect and uniform structure, which embraces in itself all other forms; its movement is in a circle, because this, by returning into itself, is most like the movement of reason. The particular points of the Timæus, the derivation of the four elements, the separation of the seven planets according to the musical scale, the opinion that the stars were immortal and heavenly substances, the affirmation that the earth holds an abiding position in the middle of the world, a view which subsequently became elaborated to the Ptolemaic system, the reference of all material figures to the triangle as the simplest plane figure, the division of inanimate nature, according to the four elements, into creatures of earth, water, and air, his discussions respecting organic nature, and especially respecting the construction of the human body—all these we need here only mention. Their philosophical worth consists not so much in their material content, but rather in their fundamental idea, that the world should be conceived as the image and the work of reason, as an organism of order, harmony, and beauty, as the good actualizing itself.