25 What say you, O men, who assign to yourselves too much of an excellence not your own? Is this the learned soul which you describe, immortal, perfect, divine, holding the fourth place under God tim Lord of the universe, and under the kindred spirits, and proceeding from the fountains of life? This is that precious being man, endowed with the loftiest powers of reason, who is said to be a microcosm, and to be made and formed after the fashion of the whole universe, superior, as has been seen, to no brute, more senseless than stock or stone; for he is unacquainted with men, and always lives, loiters idly in the still deserts although he were rich, lived years without number, and never escaped from the bonds of the body.
But when he goes to school, you say, and is instructed by the teaching of masters, he is made wise, learned, and lays aside the ignorance which till now clung to him. And an ass, and an ox as well, if compelled by constant practice, learn to plough and grind; a horse, to submit to the yoke, and obey the reins in running; a camel, to kneel down when being either loaded or unloaded; a dove, when set free, to fly back to its master's house; a dog, on finding game, to check and repress its barking; a parrot, too, to articulate words; and a crow to utter names.
Source: Against the Heathen (New Advent)