XVIII. (89) On which account some of the Stoics also, being gifted with a more acute discernment, and perceiving that they would infallibly be convicted, thought it well to be beforehand in preparing assistance as it were for a defunct proposition. But what they prepared was of no use; for, since fire is the cause of all motion, and since motion is the beginning of generation, for it is impossible that anything whatever should be generated without motion, they said that before the new world began to be formed, when it was beginning to be fashioned, the whole fire would not be extinguished in that conflagration; that they affirmed that some would still remain, but yet only a small portion. For they were exceedingly cautious, lest if it should be wholly extinguished, the consequence would be that everything would remain motionless and devoid of ornament, inasmuch as the cause of motion would no longer be in any existence. (90) But all these ideas are the invention of quibblers, who employ all their artifices in opposition to the truth. Why so? Because it is impossible, as has been proved already, that the world, after it has been destroyed by conflagration, should become similar to coal, inasmuch as there is a vast quantity of earthy substance left in which the fire must of necessity lie in ambush. And perhaps too the conflagration could not prevail in every quarter, if the heaviest and most invincible of the elements, namely the earth, still remains, without being dissolved; but it must of necessity change, either into flame or into light: into flame, as Cleanthes thought; into light, as Chryssipus conceived. (91) But if it becomes flame, then, when it approaches extinction, it will be extinguished all at once, and not partially or gradually. For the nutriment exists along with it; on which account, while there is a great deal of it, it increases and is diffused; but when it is stunted it becomes less. And any one might conjecture the truth of what takes place from what he sees happen among us. A lamp, when any one pours oil upon it, gives forth a most brilliant flame; but when any one ceases to supply it with that nutriment, and leaves only a small portion in the lamp, then the lamp is at once extinguished, and does not give out the smallest portion of flame. (92) If again this is not the case, but if the world becomes light, then again it changes altogether. Why so? Because it has no substance or character of its own, but is generated from flame, and when this is wholly and completely extinguished in all its parts, it follows of necessity that the light also must be extinguished, and that not partially, but altogether. For what flame is to nourishment, that also is light to flame. (93) As therefore the flame is extinguished concurrently with the want of nourishment, so also is the light simultaneously with the flame, so that it is actually impossible for the world to be capable of regeneration, if there is no seminal principle lurking and kindled within it, but if all things are expended and destroyed, some by fire, and some by want. From all which arguments it is plain that the world is for ever uncreated and imperishable.