Over twenty articles written in a variety of hands have been brought together in this compilation. Included are works that cover varied aspects of medieval science: medicine, computation, arithmetic, music, astronomy and astrology. The first part of the volume contains several astrological texts. As well as an introduction to the subject, there are theses on the virtues of the moon, the conception of the sphere and its diverse circles, the quantities of the stars and planets, the motion of the eighth sphere, the motion of Aries and Libra, and the theory of the planets.
The opening displayed is from an illustrated paper on the motions of the planets by an unknown author. The diagrams show planetary orbits in connection with the workings of the sun and the moon; both are seen in relation to astrological positions (marked on the outermost perimeter of the spheres), emphasizing the inseparability of medieval astronomy and astrology. It was believed that the earth was at the center of a concentric planetary system and that each planet could affect human life in particular and different ways. Thus, in The Knight’s Tale, Arcite registers his sense of being under planetary control by blaming Saturn for his misfortune.