"While I was looking at the earth stupified, when I regained my senses, I said, "What's this sound, which fills my ears so greatly and so sweetly?" [My grandfather] said, "This is that which, separated by different intervals, but still rationally distinguished according to a fixed plan, is caused by the striking and motion of the orbits themselves and, tempering high with low causes various harmonies equally. Indeed such motion could not be effected in silence! And nature brings it about that the extremes from one part sound low, from another part high. For which reason that greatest starbearing course in the sky, whose turning is very quick, is moved by a high and loud sound, while this small lunar course sounds the lowest. For the earth, the ninth sphere, remains immobile, always fixed to one place embracing its center. Indeed, these eight courses, two of which move with the same force, create the seven sounds distinct by intervals, which number is the crux of nearly all things. Learned men imitating this sound with strings and songs open a return for themselves to this heavenly place, just like others who pursue divine studies by excellent skill during their human lives.

"The ears of men, filled with this sound, have become deaf; indeed, there is no sense that's duller in you, just as when the Nile rushes from the highest mountains to that which is called Catadupa, the tribe which dwells by that place lacks the sense of hearing because of the magnitude of the sound. This sound truly is so great in all the world because of the great swiftness of its turning that the ears of men are not able to capture it, just as you are not able to look at the sun and its rays overcome your sense of sight." I wondered at this, but nevertheless I kept turning my eyes back towards the earth repeatedly.

"Then Africanus [my grandfather] said, "I see that even now you contemplate your planet and the home of men; if it looks so small to you (as it is), always regard these heavenly things; despise those human things. For what renown can you attain among the talkings of men or of that glory which is to be sought? You see that the earth is inhabited in scattered and confined places, and where it is inhabited, as if by spots, vast solitudes are placed between, and those who inhabit it are not only scattered about so much that nothing is able to pass between them one group to another, but live partly in every other zone of each hemisphere, and from them you can certainly expect no glory."

-Mark Tully Cicero, on the music of the spheres