Chapter 3. What is peace

The world is the whole universe, consisting of heaven and earth, formed of the four elements, and having the form of an absolute [4] sphere; [it is formed] from the fire with which the stars shine; from the air that all living things breathe; of the waters that encircle and permeate the earth and thereby strengthen it; Finally, from the earth itself, which is in equilibrium in the middle and at the very bottom of the world [5] and hangs motionless while the universe revolves around it. Heaven is called mundus because of its perfect and absolute grace, just as the Greeks call it KOSMOS because of its beauty [6].

Chapter 4. About the elements[7]

The elements differ from each other both in nature and in place. The earth, as the heaviest, which no other nature can bear, occupies the lowest place in all creation. Water is as much lighter than earth as it is heavier than air, so that if air is mixed with water in a vessel, it immediately rises to the top as lighter. In the same way, a fire, if it is kindled, always strives upwards to its natural place above the air. But in order to prevent this from happening (i.e., so that it does not fly away entirely. — T.B.), a soft, compressive air is spread around the fire, in which the fire is dispersed and weakened [8]. [The elements] are mixed together by a certain commonality of nature in the following way: dry and cold earth [mixes] with cold water, and water, cold and [144] moist, with moist air; then the moist and hot air is combined with the hot fire, and the hot and dry fire is combined with the dry earth. For this reason we see fire on (in) the earth, and clouds and earth-born bodies in the air.

Chapter 5. About the Firmament

The sky has a subtle and fiery nature, it is round, everywhere equally dense, and everywhere it is at equal distances from the center of the earth. The Sages9 said that the vault of the heavens and its middle, as far as we can trace its movement, goes through its daily rotation with incredible rapidity. So it would have collapsed if the counter-motion of the planets had not moderated it. In proving this point, they point to the stars that always revolve along the same path, and those in the north describe smaller circles around the point of intersection of the celestial axis with the vault.

The outermost peaks [of the firmament], around which the celestial sphere revolves, are called poles and are bound by eternal ice. One of them, rising to the north, [is called] Boreas; the second, descending to the south, is Australia; The Holy Scriptures call it "interiora austri" [11].

Chapter 6. On the different heights of the sky[12]

But the world is not so situated in relation to this upper pole that the stars near it are visible from everywhere: in fact, those stars which seem highest to us and to our neighbors are visible to those who are far away [from us] near the horizon. And if we see the pole directly above our heads, when we cross over to the other slope of the earth, the stars that were formerly above our heads will disappear from us, because the bulge of the globe is an obstacle to our view, so that the Seven Stars, hanging at the pole above our heads, appears somewhere in India for hardly 15 days a year.

Chapter 7. About the upper sky

The heaven of the uppermost circle, separated [from the rest of the circles] by a special boundary and separated everywhere by equal distances [from the lower heaven — Bridifert's gloss] [14], is the seat of the angelic powers; descending to us, they put on ethereal bodies, so that they can even eat food like a man, and when they return they throw it off. The [fiery] nature of this heaven was softened by God with glaciated waters[15] so that it would not inflame the underlying elements. Then he made the lowest heaven solid, giving it not the same but a varied motion, and called it the firmament, because it supports the upper waters.

Chapter 8. About the heavenly waters

As for the waters [16] that lie above the firmament,[17] below the spiritual heavens, but above all bodily creation, some think that they are stored here for a new [146] flood,[146] while others assert, and much more justly, that they are there to moderate the flames of the luminaries.18

Chapter 9. About the five belts of the world