Argument the Tenth.
Each of the elements of which the world consists, when in its proper place, either remains in that place, or is moved in a circle; * but when it is not in its own place, it endeavours to arrive thither. If, therefore, the elements of the universe either remain in their proper place, or are moved in a circle; if they remain in the place which is natural to them, they are then in a natural condition of being; but if they are moved in a circle, they will neither have an end nor a beginning of their motion. And this being the case, it is evident that the universe is immutable, some things in it having places adapted to them according to nature, but others being moved without beginning and without end. For the natures in this sublunary region are changed, in consequence of being in a foreign place, and the things of which they consist hastening to obtain their proper abode. If, therefore, the elements of the universe are in their proper places, and nothing which ranks as a whole tends to a foreign place, nor if it did, could oiler violence to that which is in its proper place, it is necessary that the universe should be immutable; since all things always subsist in it according to nature, not only such as rank as wholes, but those that permanently abide in it, and those that are moved. Hence, if before the universe was adorned, the natures which it contained were in their proper places, they either permanently remained in it, or were moved in a circle, and thus again the universe was adorned before it was adorned, and had no temporal beginning of its adornment; all things subsisting in it in a similar manner, both now and formerly. But if the several natures which the universe contains were in foreign places, (for they were entirely in places, being bodies,) they would require a transposition derived from an external cause. * Hence, there will be two principles, one of that which is preternatural, but the other of that which is according to nature; and that which is preternatural will be prior to that which is according to nature; † that which is preternatural being a departure from nature. But nature having no existence whatever, (if these things are admitted,) neither will there be that which is preternatural; just as if art had no existence, neither would there be that which is not conformable to art. For that existing which is not according or conformable to a certain thing, will be in consequence of that existing to which it is not conformable. So that if there were places of these according to nature, it is immanifest whether these places, being more ancient, subsisted naturally for an infinite time. But if there were no other places which were the proper receptacles of these, neither would those places be foreign in which they were situated: for that which is foreign is referred to that which is proper or peculiar. If, however, then also these natures were not in foreign places, when they were in the receptacles which they then had, just as now they are not in foreign places, it follows that they then likewise had an existence according to nature, in the same manner as they now have. Hence, the world will always exist; at different times different things subsisting, either according to nature, or preternaturally, with reference to the beings which the world contains. Hence, too, the world, so far as it is the world, is perpetual. But a thing of this kind exists in the world alone. * And if such a thing does not always exist, the universe will be transformed, yet still will be perpetual. And as that preternatural subsistence is to what now exists, so is what is now preternatural to that. Both in that state of things likewise, and in this, all things existed in their proper places; but differently at different times. Empedocles, likewise, wisely supposes the world to be made alternately, except that he supposes this to take place frequently; but we admit it to take place only twice.