  The introduction on substance and accident leads Ibn Daud to a discussion of the question of the sense in which form and matter, the two constituents of physical beings, are substances, which allows Ibn Daud to introduce the notions of potentiality and actuality. He then proceeds to deal with other basic principles of Aristotelian philosophy, such as motion and infinity. I will not go into detail here, since Ibn Daud’s exposition does not actually provide any important new insights. Instead his aim is to introduce the beginning student to Aristotelian physics and metaphysics. However, it is worth noting that, while earlier Jewish philosophers, such as Ibn Zaddiq, had dealt with substance and accident and other such principles, Ibn Daud is the first to do so coherently and comprehensively from an Aristotelian viewpoint. His proofs for the theses that every motion requires a mover and that the existence of an infinite series in actuality is impossible are two cases in point. The same can be said of his expositions on the soul.