ARISTOTLE and the Mathematicians teach that the heaven is round, and they teach truly; for since the heaven is the first of all bodies, the simplest, the most capacious, the most perfect, and the most mobile, it most of all demands a globe-shaped figure, as being the first of all figures, the simplest, the most capacious, the most perfect, and the fittest for swiftness and perpetuity of motion. And if the heaven were not endowed with this figure, motions so diverse and toward such diverse parts could not be carried on in the heavens without the heavens breaking and rupturing themselves, nor could it be avoided that, by reason of the revolutions of the heavens, a void should somewhere exist. Wherefore we are not to follow certain Ecclesiastical writers, who not only denied that the heaven is round, but even reckoned it to be contrary to the sacred writings. In which opinion Justin seems to have been, answering the 130th question of the orthodox, and Basil in homily 1 on Genesis, Ambrose in book 1 of the Hexameron, and also Chrysostom in homilies 14 and 27 on Paul's epistle to the Hebrews, on chapter 8 of that epistle, Theophylact and Theodoret (although the latter, in question 20 on Genesis, seems to follow the true opinion about the rotundity of the heaven). But beyond the rest, Lactantius stubbornly fights for this opinion, in book 3 of the Divine Institutions, chapter 23, and Procopius of Gaza in his Commentary on Genesis, when he expounds those words of Moses, In the beginning God created heaven and earth: who did not fear to say that the opinion about the rotundity of the heaven in no way agrees with the orthodox truth, but contradicts Moses, the Prophets, Paul, and even Christ the Lord.²

BUT in truth, so far is this opinion from being contrary to divine Scrip[ture]...³

...Scripture, that on the contrary it agrees and accords with it marvelously. I could, to give credence to this matter, bring forth many things from the sacred writings, but lest I be too long where there is least need, I shall be content with a few. That the heaven is round, Scripture indicates neither in one place only nor obscurely: for this Solomon left written and attested at the beginning of the book of Ecclesiastes, teaching that the Sun moves in the heaven in a circle: The Sun, he says, rises and sets, and returns to its place, and there, rising again, it wheels through the South and bends toward the North; surveying all things in its circuit the wind goes, and returns upon its circles: by which words it is most clearly shown—especially as the blessed Jerome interprets that passage—that the sun, which runs its course in the heaven, is carried round in an orb; which could not happen unless the heaven were globular and round. But still more plainly is this delivered in the book of Ecclesiasticus, chapter 24, where the divine Wisdom is brought in speaking thus: I alone have compassed the circuit of heaven. In Greek the word is more expressive, ἐκύκλωσα, that is, ‘I led around, I made round, or I rounded into a ball.’ This same thing some think Job signified, when in chapter 9 he said, Under whom they bow that bear up the world: by which words insinuating the holy Angels, by whom the celestial orbs are moved and the whole world is governed under God. To the same purpose looks that saying of Solomon in chapter 8 of Proverbs, When he prepared the heavens I was present, when by a fixed law and a circle he hedged in the depths. For by the name ‘deep’ he here signifies that vast space between heaven and earth, full of watery matter, without any light and distinction, of which Moses said in this place, And darkness was upon the face of the deep. And this deep he hedged about and circumscribed with a circle—that is, with the circle of the celestial bodies—and with a fixed law that cannot be changed. And this the Hebrew reading shows more plainly, which word for word sounds: When he set, or described, a circle upon the face of the deep.⁴

BUT to Basil, Ambrose, Acacius, and certain others of the old writers, that passage of Isaiah in chapter 40 seemed utterly to overturn the opinion about the rotundity of the heaven—where it is said that God stretched out the heavens like a tent or chamber, or, as Basil cites it from the translation of the Seventy Interpreters, set up the heaven like a vault; and that other passage of David in Psalm 103, Stretching out the heaven like a skin. Nevertheless Augustine, in chapter 9 of book 2 of On Genesis according to the Letter, beautifully teaches how the aforesaid texts can most conveniently be understood and expounded, so that they in no way at all stand against the rotundity of the heaven. For, says Augustine, that the heaven is round does not conflict with its having a likeness to a tent or chamber: for the heaven, in respect of that part which is above us—of which Scripture properly speaks—has the likeness of a chamber, covering over this our hemisphere; wherefore, if the heaven is not spherical, it is on that side a chamber by which it covers the earth; but if it is wholly spherical, it is a chamber on both sides: for, just as this part of the heaven which covers us is, as it were, a chamber in respect of our hemisphere, so the other half of the heaven which covers the Antipodes is, in respect of the hemisphere opposite to us, a chamber. Nor does it stand in the way that David says the heaven was stretched out like a skin: for a skin...⁵

...a skin can be stretched both flat and into a round, as we see in a wineskin, a ball, a bladder: so Augustine. It is to be known, however, that in that passage of David the Hebrew word for ‘skin’ is one that means ‘curtain’: for of old, both among the Jews and among other nations, tents and pavilions were made of skins after the fashion of curtains; whence flowed that saying, that emperors are ‘under skins’ (i.e., in tents). You have an example of this, reader, in the canticle of Habakkuk, chapter 3, in that place: For iniquity I saw the tents of Ethiopia; the curtains of the land of Midian shall be troubled. Therefore the true and genuine sense of those words of David is this: Just as a man, without any trouble, draws out and spreads as he pleases the skin or curtain of his tent or pavilion, folded and rolled up, so God without labor stretched out the heaven into the greatest amplitude, that it might be like a tent and pavilion covering round the earth, which He had given to all living things, but chiefly to men, to dwell in.⁶