 No doubt, Aristotle did not make it easy for Averroes who complains how long he took great pains to find the explanation (cum grande labore et in tempore vitae meæ non modico LC 427D). But once proven that the first mover is not a body, it becomes easier: the First Mover does not need to be affected by the mentioned restrictions of corporeal movers, and it can produce motion for an infinite time. And the First Mover becomes a metaphysical principle like Prime Matter.