 Philoponus disagreed with Aristotle and affirmed the existence of the void and the possibility of motion in it (CAG 17: 675–695). Centuries later, Avempace denied the role of the medium as being necessary for motion, and maintained that bodies can move in the void, but a direct influence of Philoponus upon him has not been proved. Averroes ignored the issue in the Short Commentary but not in the Middle Commentary. Averroes organizes the arguments against the existence of the void in proofs, and the third proof as stated in MC Book IV, section 2, chapter 5 maintains that if there is no medium (emṣaՙi), motion will happen in no time, and that this is not possible. He opposes Avempace’s view that the stone can naturally move in time in the void and that the medium only makes its natural motion slower; the medium water slows down its fall less than the medium air does (MC Kalonymos L 52vº20–53rº23). Natural motion has its own velocity and the medium deducts from it, so that