The Sphere of the World with Commentaries

inferior things. Or it is called from zodion which is animal, because since it is divided into 12 equal parts, each part is called a sign, and it has a special name from the name of some animal, on account of some property suitable both to it and to the animal, or on account of the disposition of the fixed stars in those parts in the manner of such animals. This circle is indeed called in Latin signifer (the sign-bearer), because it bears the signs, or because it is divided into them. By Aristotle, however, in the book On Generation and Corruption, it is called the oblique circle, where he says that according to the approach and recession of the sun in the oblique circle, generations and corruptions occur in inferior things. The names of the signs, their ordering, and number are evident in these verses: "Aries, Taurus, Gemini, Cancer, Leo, Virgo, / Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces." Each sign is divided into 30 degrees. Whence it is evident that in the whole zodiac there are 360 degrees. According to astronomers, again, each degree is divided into 60 minutes, each minute into 60 seconds, each second into 60 thirds, and so on up to the tenths; and just as the zodiac is divided by the astronomer, so is any circle in the sphere, whether greater or smaller, into similar parts. Since every circle in the sphere, moreover, except for the zodiac, is understood as a line or circumference, only the zodiac is understood as a surface having 12 degrees in its latitude, of which degrees we have now spoken. Whence it is evident that certain people err in astrology by saying that the signs are square, unless, abusing the name, they call the same thing square and quadrilateral. For a sign has 30 degrees in length, but 12 in latitude. The line dividing the zodiac in its circuit such that it leaves six degrees on one side of itself and another six on the other side is called the ecliptic line, since when the sun and moon are linearly beneath it, an eclipse of the sun or moon occurs. Of the sun: as if a new moon occurs and the moon is interposed directly between our sight and the solar body. Of the moon: as in the full moon, since the sun is opposed to the moon diametrically. Whence an eclipse of the moon is nothing other than the interposition of the Earth between the body of the sun and the moon. The sun indeed always runs beneath the ecliptic, all other planets decline either towards the north or towards the south; sometimes, however, they are beneath the ecliptic. But the part of the zodiac which declines from the equinoctial