 Whereas in DOS Kilwardby remains neutral to any of these views, in QLIIS 15 he seems to align himself with the view that the essential unity of matter is analogical, not numerically one. In E 2, however, Kilwardby approaches the question in slightly different terms, which can be explained by the fact that his motivation is different: whereas in DOS and QLIIS he intends to justify the distinction between corporeal and spiritual things, in E he wants to understand matter as that which underlies change. From that point of view, there are three kinds of prime matter: