52 And yet, lest you should suppose that none but yourselves can make use of conjectures and surmises, we too are able to bring them forward as well, as your question is appropriate to either side. Whence, you say, are men; and what or whence are the souls of these men? Whence, we will ask, are elephants, bulls, stags, mules, asses? Whence lions, horses, dogs, wolves, panthers; and what or whence are the souls of these creatures? For it is not credible that from that Platonic cup, which Timaeus prepares and mixes, either their souls came, or that the locust, mouse, shrew, cockroach, frog, centipede, should be believed to have been quickened and to live, because they have a cause and origin of birth in the elements themselves, if there are in these secret and very little known means for producing the creatures which live in each of them.
For we see that some of the wise say that the earth is mother of men, that others join with it water, that others add to these breath of air, but that some say that the sun is their framer, and that, having been quickened by his rays, they are filled with the stir of life. What if it is not these, and is something else another cause another method, another power, in fine, unheard of and unknown to us by name, which may have fashioned the human race, and connected it with things as established; may it not be that men sprang up in this way, and that the cause of their birth does not go back to the Supreme God?
For what reason do we suppose that the great Plato had— a man reverent and scrupulous in his wisdom— when he withdrew the fashioning of man from the highest God, and transferred it to some lesser deities. and when he would not have the souls of men formed of that pure mixture of which he had made the soul of the universe, except that he thought the forming of man unworthy of God, and the fashioning of a feeble being not beseeming His greatness and excellence?
Source: Against the Heathen (New Advent)