Plato now describes how the self-identical, as itself a moment, and the other or matter, and the third, the apparently dissoluble union which has not returned into the first unity—which three were originally separated—have now, in simple reflection into self and resumption of that beginning, been degraded into moments. “Mingling the identical and the other with the essence (οὐσία),” the third moment, “and making them all one, God again divided this whole into as many parts was as fitting.”[52] Since this substance of the soul is identical with that of the visible world, the one whole is for the first time the now systematized substance, the true matter, the absolute element which is internally divided, an enduring and unseparable unity of the one and many; and no other essence must be demanded. The manner and mode of the division of this subjectivity contain the famous Platonic numbers, which doubtless originally pertain to the Pythagoreans, and respecting which both ancients and moderns, and even Kepler himself in his _Harmonia mundi_, have taken much pains, but which no one has properly understood. To understand would mean two things, and in the first place, the recognition of their speculative significance, their Notion. But, as already remarked of the Pythagoreans (Vol. I. p. 224), these distinctions of number give only an indefinite conception of difference, and that only in the earlier numbers; where the relationships become more complicated, they are quite incapable of designating them more closely. In the second place, because of their being numbers, they express, as differences of magnitude, differences in what is sensuous only. The system of apparent magnitude—and it is in the heavenly system that magnitude appears most purely and freely, liberated from what is qualitative—must correspond to them. But these living number-spheres are themselves systems composed of many elements—both of the magnitude of distance and of velocity and mass. No one of these elements, taken as a succession of simple numbers, can be likened to the system of heavenly spheres, for the series corresponding to this system can, as to its members, contain nothing else than the system of all these moments. Now if the Platonic numbers were also the elements of each system such as this, it would not be only this element which would have to be taken into account, for the relationship of moments which become distinguished in movement has to be conceived of as a whole, and is the true object of interest and reason. What we have to do is to give briefly the main points as matter of history; we have the most thorough treatment of it given us by Böckh “On the Constitution of the World-Soul in the Timæus of Plato,” in the third volume of the Studies of Daub and Creuzer (p. 26 _et seq._).