 In both early and later works, Bacon objects to the idea that matter is one in number in all things. The background to this issue arises in the 1240s to 1270s of the Fons vitae of Avicebron (Solomon Ibn Gebirol) and from Franciscan discussions at Paris on the nature of the unity of matter. Bacon holds that matter “is not numerically one, but in itself and from itself it is numerically distinct in numerically different beings.” Still, he does not object to a logical unity of matter. For example, matter as potentiality is the original source of the being of contingent things. This is the non-being of the creature in contrast with the being of the Creator. Matter properly speaking is prime matter. This must be distinguished from both natural matter and from artificial matterThus, Bacon will speak of the matter of both corporeal and spiritual beings, and hence of “spiritual matter,” a concept that Aquinas found to be contradictory.