X. 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.”