But we must examine this question more accurately, in the following manner.
There are three species in fire; the coal, and the flame, and the light. Now coal is the fire in its earthy substance, which, like a sort of spiritual habit, couches and lies hid in a sort of cavern, pervading it all to its very extremities. And the flame is that part which, being raised on high, is lifted up from its fuel. And the light is that which is emitted from the flame, so as to co-operate with the eyes, in order to enable them to comprehend what is seen. And the flame occupies the middle position between the coal and the light; for when it is extinguished it ends in coal, and when it is kindled it excites the light, which, being deprived of its burning power, blazes. If therefore, we affirm that the world is dissolved by conflagration, it would not be coal, because, in that case there will be a great deal of the earthy substance left behind, in which also fire must necessarily be contained. But we must agree, that none of the other bodies subsist any longer, but that earth, and water, and air, are all dissolved into unmixed fire. Nor, again, would it become flame; for that can only exist in connexion with nourishment; and, if nothing is left behind, being deprived of all nourishment it will immediately be extinguished. It follows from all this, that it cannot become light either; for light by itself has no substance at all, but flows from the things before mentioned, coal and flame, not in a great degree from the coal, but very much from the flame; for it is diffused over a very great space indeed. But if, as has been already proved, those things had no existence from the conflagration of all things, then there could not be any light either. For the abundant, and vast, and extensive brilliancy of mid-day, when the sun proceeds under the earth, is at once caused to disappear by night, especially if it be a moonless night. Therefore the world is not destroyed by fire, but is indestructible. And if it should be destroyed by fire, there could not be another created.
 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. 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 Chrysippus conceived.