Book One:
[215] Then follows this, that nature breaks up each thing again into its own first-bodies, nor does she destroy ought into nothing. For if anything were mortal in all its parts, each thing would on a sudden be snatched from our eyes, and pass away. For there would be no need of any force, such as might cause disunion in its parts and unloose its fastenings. But as it is, because all things are put together of everlasting seeds, until some force has met them to batter things asunder with its blow, or to make its way inward through the empty voids and break things up, nature suffers not the destruction of anything to be seen.
Book Five:
[235] First of all, since the body of earth and moisture, and the light breath of the winds and burning heat, of which this sum of things is seen to be made up, are all created of a body that has birth and death, of such, too, must we think that the whole nature of the world is fashioned. For verily things whose parts and limbs we see to be of a body that has birth and of mortal shapes, themselves too we perceive always to have death and birth likewise. Wherefore, when we see the mighty members and parts of the world consumed away and brought to birth again, we may know that sky too likewise and earth had some time of first-beginning, and will suffer destruction.