The Motion of the Heavens

Aristotle believes that the world is eternal, a central claim in both physics and on the heavens. When giraffes lope across the savannah That motion can be traced very indirectly back to the single, simple rotation of the outermost sphere. Aristotle seems to have improved upon the mathematicians here by positing several actual physical spheres for each required planetary motion with further spheres to counteract those motions.