XIII. (69) We have now then discussed at sufficient length the nonsense in opposition to truth which is uttered by those who build up falsehood and fables. But we must be well assured that men have from all eternity sprung from other men in constant succession, the man implanting the seed in the woman as in a field, and the woman receiving the seed so as to preserve it, and nature by her unseen operations fashioning everything, and each separate part of the body and of the soul, and giving to the whole race of mankind that which each individual separately is unable to receive, namely, the principle of immortality; for though the individual members are continually perishing, yet the race remains undying as a truly divine work. But if man, who is but a small portion of the universe, is eternal, then certainly the world itself must have been uncreated so as to be imperishable.

XIV. (70) But Critolaus, in arguing in support of his opinion, brought forward an argument of this kind, –“That which is the cause to man of his being in health is itself free from disease, and, in like manner, the cause of his keeping awake must itself be sleepless; and if this is the case, that which is the cause of his existing for ever must itself also be everlasting.” Now the cause of man’s existing for ever is the world, since it is so to all other things whatever; therefore the world also is immortal. (71) Nevertheless, this point also is worthy of one consideration: that everything which is born must by all means at the beginning be imperfect, but as time advances he must increase till he arrives at complete perfection, so that if the world was born it was at one time (that I may use the expressions appropriate to the ages of men) a mere infant, and subsequently increasing in periods of years and lapse of time, it at last and with great difficulty arrived at perfection, for of necessity the period at which that which of all things has the longest existence must be late. (72) But if any one fancies that the world has ever really been subjected to such changes as these, it is time that he should learn that he has been under the influence of incurable madness, for it is plain that if that is the case not only will its bodily appearance be increased, but its mind also will receive growth, since they who attribute liability to perish to it conceive it to be a rational creature. (73) Therefore, just like a man, it will be devoid of reason at the commencement of its existence, but endowed with reason at the age when it is in its prime, which it is impious not only to say, but even to think, for how can we imagine the most perfect visible circumference which surrounds us, and which contains within itself so many individual inhabitants, is not always perfect both in soul and body, being exempt from all those evils in which everything which has been born and which is perishable is implicated?