Note e — MUNDI THEMA, OR THE GENITURE OF THE WORLD. TRANSLATED FROM THE THIRD BOOK OF THE MATHESIS OF JULIUS FIRMICUS MATERNUS.

Page 59.—Plato, in the eighth book of his Republic, speaking of the dissolution of the city which he has constituted, observes as follows: “Not only with respect to terrestrial plants, but likewise in terrestrial animals, a fertility and sterility of soul as well as of body takes place, when the revolutions of the heavenly bodies complete the periphery of their respective orbits; which are shorter to the shorter lived, and contrarywise to such as are the contrary.” The necessity for such a mutation taking place is this (as I have observed in the Introduction to my Translation of Aristotle’s History of Animals),—that all the parts of the universe are unable to participate the providence of divinity in a similar manner, but some of its parts enjoy this perpetually, and others only for a time; some in a primary, and others in a secondary degree. For the universe, being a perfect whole, must have a first, a middle, and a last part. But its first part, as having the most excellent subsistence, must always exist according to nature; and its last part must sometimes subsist according to, and sometimes contrary to, nature. Hence the celestial bodies, which are the first parts of the universe, perpetually subsist according to nature, both the whole spheres and the multitude co-ordinate to these wholes[57]; and the only alteration which they experience is a mutation of figure, and variation of light at different periods; but in the sublunary region, while the spheres of the elements remain, on account of their subsistence as wholes, always according to nature, the parts of these wholes have sometimes a natural, and sometimes an unnatural subsistence; for thus alone can the circle of generation unfold all the variety which it contains.