“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.”{13}{a fragment from the Chrysippus of Euripides.}

And this law and ordinance is established with reference to everything which is destroyed, that wherever composite things are existing in combination they are thrown into disorder instead of into the order in accordance with nature, which they previously enjoyed, and they are removed to situations opposite to those in which they were previously placed, so that they seem in a manner to be sojourners; and when they are dissolved again, then they return to the appropriate parts allotted to them by nature. But since the world has no participation in that irregularity which exists in the things which I have just been mentioning, let us stop awhile and consider this point. If the world were liable to corruption and destruction, it follows of necessity that all its parts would at present be arranged in a position not in accordance with nature: but it is impious even to imagine such a thing as this; for all the parts of the world have received the most excellent position possible, and an arrangement of the purest symmetry and harmony; so that each individual part, being content with its place as a native country to it, does not seek any change for the better. On this account it is that the most central position of all has been assigned to the earth, to which all things belonging to it adhere, and to which they descend again even if you throw them into the air: and this is a proof that their place is in accordance with nature; for wherever anything is borne without any violence, and where it then remains firm and stationary, that is clearly its natural place. And then, in the second place, water was poured over the earth, and air and fire have gone from the central to the upper part, air having received for its portion the region which is on the borders between air and fire, and fire having received the highest place of all: on which account, if you light a torch and press it down towards the ground, nevertheless the flame will still turn in a contrary direction, and lightening itself in accordance with the natural motion of fire, will rise upwards: if, then, motion contrary to nature is the cause of corruptibility and destruction in the case of other animals, but if in the case of the world every one of its parts is arranged in complete accordance with nature, having had appropriate positions allotted to each of them, then surely the world must most justly be pronounced incorruptible and imperishable.