The nature of motion -- Causes, forces, and resistance -- The concept of the function in fourteenth-century physics -- The significance of the theory of impetus for Scholastic natural philosophy -- Galileo and the Scholastic theory of impetus -- The theory of the elements and the problem of their participation in compounds -- The achievements of late Scholastic natural philosophy.

Avicenna’s theory of compounds had virtually no effect on scholastic philosophy. It is always mentioned, indeed, but only to be rejected. At most, one finds that certain thinkers take up this or that particular thought of his; or that, regarding the issue of compounds, the fundamental Averroistic or Thomistic position exhibits a certain Avicennistic tinge. This is particularly the case when it comes to Albertus Magnus, who wants to follow the thoroughly Aristotelian-Averroistic conception, while being convinced that the doctrines of (...) Averroes and Avicenna are fundamentally the same. His judgment agrees above all with that of Averroes. Since one and the same matter cannot receive many substantial forms, one cannot say that the elements in the compound are contained such that the substantial forms are wholly preserved. On the other hand, however, since the properties of the elements are found in the compound body, neither can one say that their substantial forms are in no way preserved. “And for that reason Aristotle said that the intensities of those substantial forms are reduced, and thus that in part they are preserved and in part they are changed: and so all arrive at an intermediate.”. (shrink)