This paper provides a historical reevaluation of the originality and implications of Avempace's critique of Aristotle's causal explanation of the motion of projectiles. It also offers a serious revision of the place which has usually been assigned to Avempace in the history of science. The views regarding projectiles defended in Avempace's Arabic commentary are in sharp opposition to the anti-Aristotelian Avempace that was known in the Medieval West through Averroes. Avempace's commentary reveals only a moderate critic of Aristotle, a critic who did not, in any case, break with the master, and who, therefore, did not even go as far as Philoponus in creating a new and more profound theory of projectile motion.