Chapter IV.
The particular quality of the earth, when it is called dry, is signified. The properties of the elements, by which they are mutually connected, are discussed; and this is specifically examined with regard to the earth.
17. But, as it seems, since we were talking about the sea, we have strayed a bit; let us return to the point and consider what the Lord says: Let the water be gathered together into one gathering, and let the dry land appear, and let it not be called, earth. Who does not notice the excellent placement of this? For the earth can be mixed with mud, wet with water, whose species does not appear when water is poured over it. But the dry land refers not only to the general nature, but also to the specific kinds of land, so that it may be useful, dry, suitable, and ready for cultivation. At the same time it is considered, lest it appear to be dried up more by the sun than by the command of God, because it became dry before the sun was created. Hence David, distinguishing the sea and the earth, says of the Lord God: For the sea is his, and he made it; and his hands founded the dry (Ps. 94:5). For the expression 'dry' is a description of nature, the appellation 'earth' is a simple designation of a matter which has its own quality. For just as the designation 'animal' signifies a type of being in which there is something proper and excellent, so also 'earth' can be said generally to be either teeming with water or barren and impassable, and without water. Therefore, even those things that are abundant in water have the ability to become dry. For when water is removed, it begins to be dry, as it is written: 'He turned rivers into a desert, springs of water into thirsty ground' (Ps. 107:33), that is, he made dry land from watery soil.
Therefore, the earth has its own specific quality, just as each element does. For air has a humid quality, water has a cold quality, and fire has a hot quality. And this is the main characteristic of each individual element, which we deduce through reason. However, if we want to comprehend sensibly and corporeally, we find them connected and composed; for example, dry and cold earth, cold and humid water, hot and humid air, hot and dry fire; and thus, through these paired qualities, the individual elements mix with one another. Since the earth is of a dry and cold nature, it is connected to water by the affinity of cold nature, and by the aid of heat, because air is moist. Therefore, water seems to embrace the earth and air with two arms, one of coldness and moisture, the other of earth and moist air. Air also, being in the middle between two opposing elements by nature, namely water and fire, reconciles both elements to itself; for it is connected to water by moisture and to fire by heat. Fire, which is also hot and dry in nature, is connected to air through heat, but is replenished with dryness through its association with earth; and in this way, they come together in a certain circuit and harmony of unity. Hence, they are called in Greek στοιχεῖα, which in Latin we call elements, because they come together and harmonize with each other.
Here, however, we have made progress, because Scripture says that God called the dry land, that is, that which is its principal attribute, by the name of 'land'. For the natural property of the land is dryness: this is its special prerogative. Therefore, dryness is the principal attribute. It also possesses coldness, but second to the first attributes. And in order to be moist, it acquires this by its affinity with water. Therefore, it is its own, this is foreign: its own, because it is dry; foreign, because it is moist. Therefore, the author of nature held on to what he first gave, because that is from nature, but this is from a cause. Therefore, the property should be defined from the main things, not from the accidents of the earth, so that our knowledge would be informed according to the prerogative of its quality.