Question

How, according to Aristotle in Book XII, is motion caused and why must motion be ongoing?

Answer 1

According to Aristotle ,motion requires a force ,the cause of such motion is that all object and substance have a natural place or level,such as air above and water below,and they proceed in the most direct way,along straight vertical paths to their natural places.The motion of celestial body is circular because this is the most perfect kind of unchanging eternal motion,whereas the necessarily transitory motions of sublunary objects are rectilinear. Aristotle have classified motion into two types natural and violet motion. Aristotle taught that to maintain motion an external force must continue to be exerted on the object . Inertia is the property of objects to mainy their motion.