19 But if men either knew themselves thoroughly, or had the slightest knowledge of God, they would never claim as their own a divine and immortal nature; nor would they think themselves something great because they have made for themselves gridirons, basins, and bowls, because they have made under-shirts, outer-shirts, cloaks, plaids, robes of state, knives, cuirasses and swords, mattocks, hatchets, ploughs. Never, I say, carried away by pride and arrogance, would they believe themselves to be deities of the first rank, and fellows of the highest in his exaltation, because they had devised the arts of grammar, music, oratory, and geometry.
For we do not see what is so wonderful in these arts, that because of their discovery the soul should be believed to be above the sun as well as all the stars, to surpass both in grandeur and essence the whole universe, of which these are parts. For what else do these assert that they can either declare or teach, than that we may learn to know the rules and differences of nouns, the intervals in the sounds of different tones, that we may speak persuasively in lawsuits, that we may measure the confines of the earth?
Now, if the soul had brought these arts with it from the celestial regions, and it were impossible not to know them, all men would long before this be busied with them over all the earth, nor would any race of men be found which would not be equally and similarly instructed in them all. But now how few musicians, logicians, and geometricians are there in the world! How few orators, poets, critics! From which it is clear, as has been said pretty frequently, that these things were discovered under the pressure of time and circumstances, and that the soul did not fly hither divinely taught, because neither are all learned, nor can all learn; and there are very many among them somewhat deficient in shrewdness, and stupid, and they are constrained to apply themselves to learning only by fear of stripes.
But if it were a fact that the things which we learn are but reminiscences — as has been maintained in the systems of the ancients— as we start from the same truth, we should all have learned alike, and remember alike— not have diverse, very numerous, and inconsistent opinions. Now, however, seeing that we each assert different things, it is clear and manifest that we have brought nothing from heaven, but become acquainted with what has arisen here, and maintain what has taken firm root in our thoughts.
Source: Against the Heathen (New Advent)