Chapter II.
The firmament is created to separate the waters from the waters. The heavens are proved to be more, and the harmony of the celestial spheres is refuted.
And God said: Let there be a firmament amidst the waters, and let it divide the waters from the waters. And it was so (Gen. I, 6). Listen to the words of God, He says 'Let it be.' It is a command, not an estimation. It commands nature, it does not obey possibility, it does not gather measurements, it does not weigh. His will is the measure of all things. His word is the purpose of the work: 'Let there be a firmament amidst the waters.' Everything that God establishes is firm. And He introduced a rather beautiful preface: Let there be a firmament, before He placed it amidst the water; so that you might believe that the firmament was made by the command of God, before you doubted the nature of the water pouring forth. If you consider the nature of the elements, how is the firmament solidified among the waters? They flow, it is restrained: they run, it remains. And He said, Let it separate the water. But water tends to confuse, not to separate. How does he command what he knows to be contrary according to the ratio of the elements? But since his speech arises from nature, he rightly claims to give the law of nature, who gave the origin.
5. But first let us consider what the firmament is, whether it is the same thing as the heaven mentioned above, or something else, and whether there are two heavens or more. For there are those who say that there is only one heaven and no other can be made, since there was, as they say, enough matter for only one, because when all the matter for the upper heaven was used up, there was nothing left to build the second or third heaven. But others assert that there are innumerable heavens and worlds, which their own people mock. For indeed, it is not greater for us to fight against them than against their own, who contend by geometric numbers and necessities to prove that there cannot be another heaven, nor can nature endure to be second or third, nor the power of the operator suitable to make many heavens. And who would not mock this skilful rhetoric of theirs, when, while they do not deny that many things of the same kind can be made by men from one and the same cause, they doubt about the creator of all, whether he could have made many heavens, concerning whom it is written, 'But the Lord made the heavens' (Psalm 95:5). And elsewhere: He has done whatever he has desired (Ps. CXIII, 3). For what is difficult for him, for whom to desire is to have already done? Therefore, their reasoning of impossibility flows away when they discuss about God, to whom it is truly said: For nothing is impossible for you.
Therefore, we cannot deny that we are not only in the second heaven, but also in the third heaven, as the Apostle confirms by testifying that he was caught up to the third heaven (2 Corinthians 12:2). David also established the heavens of heavens in praise of the Lord (Psalm 148). Following his example, philosophers introduced the harmonious motion of five planets, the sun, and the moon, describing how all things are connected by their orbits or rather globes that are thought to rotate backwards and contrary to the motion of the rest. And by this impulse and motion of these spheres, a sweet and full sound of artistry and pleasing modulation is produced, as the divided air, with its artful motion and the tempering of high and low notes, creates harmonies so varied and evenly balanced that it surpasses the sweetness of any musical composition.
If you seek and expect proof of this matter to be proven to us by sense and hearing, there is hesitation. For if they were true, how would the celestial sphere, which is said to have the courses of the fixed stars attached to it and that are constantly revolving with great motion, have a more rapid revolution and produce a sharper sound, while the lunar sphere, on the other hand, which is the heaviest, would not be heard by us, when we are accustomed to hearing lighter sounds? Therefore, if we demand proof of the truth of this discussion by means of our testimony and the function of hearing, they report that our ears have become deaf and our sense of hearing has become dull because of that customary sound that we have had since the beginning of our generation. And they bring forward an example, namely that the Nile, the greatest of rivers, in that very place where it hurls itself down from the highest mountains in that waterfall, blocks the ears of the people living nearby with the magnitude of its roar, so that they are said to lack the gift of hearing. But the truth easily refutes these things itself. For if we were to hear the thunder generated by the collision of clouds, the movements of such great orbs, which are certainly estimated to move with a larger motion, would they not also produce louder sounds? Moreover, they add that for this reason this sound does not reach the lands, so that captivated humans, through its sweetness and charm, which that fastest movement of the heavens has produced, from the eastern regions all the way to the west, would abandon their own affairs and tasks, and everything would remain idle here, by some departure of the human mind from earthly sounds to celestial ones. But let us leave those things that are foreign to our study and to the sequence of divine reading to those who are outside: let us adhere to the guidance of the heavenly Scriptures.