De Aeternitate Mundi

And if the world also is destroyed, then it must of necessity be so either by some external cause, or else by some one of the powers which exist within itself; and both these alternatives are impossible, for there is nothing whatever outside of the world, since all things are brought together in order to make it complete and full, for it is in this way that it will be one, and whole, and free from old age; it will be one, because if anything were left outside of it, then another world might be created resembling that which exists now; and whole, because the whole of its essence is expended on itself; and exempt from old age and from all disease, since those bodies which are liable to be destroyed by disease or old age are violently overthrown by external causes, such as heat, and cold, and other contrary qualities, no power of which is able to escape so as to surround and attack the world, all those being entirely enclosed within, without any part whatever being separated from the rest. But if indeed there is any external thing it must by all means be a vacuum, or else a nature absolutely impossible, which it would be impossible should either suffer or do anything.

And again, it will also not be dissolved by any cause existing within itself; first of all because, if it were, then the part would be greater and more powerful than the

and a proof of this may be found in oxen, and horses, and men, and other animals of similar kinds, because it is their nature to be destroyed by the sword, or to be liable to die by disease; for it is difficult, or I might rather say impossible, to find anything which, being by nature at the mercy of some external cause perceptible by the intellect, will still not be liable to corruption ... by itself when the world was not.

Since, therefore, the arrangement of the world is such as I have endeavoured to describe it, so that there is no part whatever left out, so as for any force to be applied, it has now been proved that the world will not be destroyed by any external thing, because in fact nothing whatever external has been left at all; nor will it be destroyed by anything in itself on account of the proof which has already been considered and stated, according to which that which was obnoxious to the power of one of those causes was also naturally susceptible of the influence of the other.

And there are testimonies also in the Timaeus to the fact of the world being exempt from disease and not liable to destruction, such as these: "Accordingly, of the four elements the constitution of the world receives each in all its integrity; for he who compounded it made it to consist of the whole of fire, and the whole of water, and the whole of air, and the whole of earth, not leaving any portion or any power of any one of them outside, from the following intentions:—

in the first place, in order that the whole might be as far as possible a perfect animal made up of perfect parts. And besides all these things, he ordained that it should be one, inasmuch as there is nothing left out of which another similar world could be composed. Moreover, he willed that it should be exempt from old age, and free from all disease, considering that those things which in the body are hot or cold, or which have mighty powers, if standing all around and falling upon it unseasonably, would be likely to dissolve it, and, by introducing diseases and old age, cause it to decay and perish. For this cause, and because of this reason, God made the whole universe to consist of entire and perfect elements, and exempt from old age and free from disease."

Let this be taken as a testimony delivered by Plato to the imperishable nature of the world. Its uncreated character follows from the truth of natural philosophy; for dissolution

The argument may be stated in a different way as follows. All compound things which are destroyed are dissolved into the elements of which they were compounded; accordingly, dissolution is nothing else but a return of everything to its original constituent parts; just as, on the contrary, composition is that which compels the things combined to come together in a manner contrary to their nature; and indeed, this appears to be the most exact truth;

for men are composed of the four elements which together make up the whole of the universe, the heaven, the earth, the air, and fire, borrowing a few parts of each in a manner at first sight hardly consistent with nature. But the things which are thus combined together are necessarily deprived of a motion in accordance with nature; for instance, warmth is deprived of its upward motion, and coldness of its downward tendency, the earthy and somewhat weighty substance being lightened and assuming the higher place, which the most earth-like of our own parts, the head, has obtained in us.

But of all bonds, that is the worst which is forged by violence, and which, being violent, is also short-lived; for it is speedily broken by those who are bound in it, since they become restive from their desire for a motion in accordance with nature, to which they hasten; for as the tragic poet says, — [*](A fragment from the Chrysippus of Euripides. )"And for things sprung from earth, they must Return unto their parent dust, While those from heavenly seed which rise Are borne uplifted to the skies. Nought that has once existed dies, Though often what has been combined Before, we separated find, Invested with another form."