But as in the words which I quoted from Celsus, which are a paraphrase from the Timæus, certain expressions occur, such as, “God made nothing mortal, but immortal things alone, while mortal things are the works of others, and the soul is a work of God, but the nature of the body is different, and there is no difference between the body of a man and that of a bat, or of a worm, or of a frog; for the matter is the same, and their corruptible part alike,”— let us discuss these points for a little; and let us show that Celsus either does not disclose his Epicurean opinions, or, as might be said by one person, has exchanged them for better, or, as another might say, has nothing in common save the name, with Celsus, the Epicurean.
For he ought, in giving expression to such opinions, and in proposing to contradict not only us, but the by no means obscure sect of philosophers who are the adherents of Zeno of Citium, to have proved that the bodies of animals are not the work of God, and that the great skill displayed in their construction did not proceed from the highest intelligence. And he ought also, with regard to the countless diversities of plants, which are regulated by an inherent, incomprehensible nature, and which have been created for the by no means despicable use of man in general, and of the animals which minister to man, whatever other reasons may be adduced for their existence, not only to have stated his opinion, but also to have shown us that it was no perfect intelligence which impressed these qualities upon the matter of plants.
And when he had once represented (various) divinities as the creators of all the bodies, the soul alone being the work of God, why did not he, who separated these great acts of creation, and apportioned them among a plurality of creators, next demonstrate by some convincing reason the existence of these diversities among divinities, some of which construct the bodies of men, and others— those, say, of beasts of burden, and others— those of wild animals? And he who saw that some divinities were the creators of dragons, and of asps, and of basilisks, and others of each plant and herb according to its species, ought to have explained the causes of these diversities.
For probably, had he given himself carefully to the investigation of each particular point, he would either have observed that it was one God who was the creator of all, and who made each thing with a certain object and for a certain reason; or if he had failed to observe this, he would have discovered the answer which he ought to return to those who assert that corruptibility is a thing indifferent in its nature; and that there was no absurdity in a world which consists of diverse materials, being formed by one architect, who constructed the different kinds of things so as to secure the good of the whole.
Or, finally, he ought to have expressed no opinion at all on so important a doctrine, since he did not intend to prove what he professed to demonstrate; unless, indeed, he who censures others for professing a simple faith, would have us to believe his mere assertions, although he gave out that he would not merely assert, but would prove his assertions.
Source: Against Celsus (New Advent)