William of Conches - The De Philosophia Mundi

The De Philosophia Mundi

The De philosophia mundi is divided into four books, covering physics, astronomy, geography, meteorology and medicine.

William explains the world as composed of elements (elementa), which he defines as "the simplest and minimum part of any body—simple in quality, minimum in quantity". He identifies the elements with the traditional four elements (fire, air, water, earth) but (following Constantine the African) not as they are perceived, since as such they are neither simple in quality nor minimum in quantity: earth, for example, contains something hot, something cold, something dry and something wet at the same time. Pure elements are not to be perceived, says William, but to be grasped by reason, through an abstract division of the sensible bodies. Each of these pure elements has two of the four basic qualities: earth is cold and dry, water is cold and humid, air is hot and humid and fire is hot and dry. The perceivable elements, called elementata, are made of pure elements: the sensible earth especially of pure earth, the sensible water especially of pure water, and so on.

The discussion of meteorology includes a description of air becoming less dense and colder as the altitude increases, and William attempts to explain the circulation of the air in connection with the circulation of the oceans. The discussion of medicine deals chiefly with procreation and childbirth. This work influenced Jean de Meung, the author of the second part of the Roman de la Rose.