الوصف
Abstract: One of the central concerns of Ibn Rushd (Averroes, d. 595/1198) in his commentaries on Aristotle was defending the theory of Eternity. This theory in Aristotle took the form of the eternal motion of the celestial sphere and its bodies. John Philoponus in his critique of Eternity tried to use one of Aristotle’s natural principles to refute his theory of the eternal motion of the celestial body. Philoponus reasoned that every body is finite and thus has finite force, so the celestial bodies cannot have infinite force, and, thus, their rotation could not be eternal. Ibn Rushd tried, in various ways and in many places of his commentaries, to defend the eternal rotation of the heavens, by refuting Philoponus’ argument. We can divide Ibn Rushd’s solution into a dialectical approach and a demonstrative approach. Dialectically, Ibn Rushd provided some principles that paved the way to convince the reader of the thesis of Eternity itself. He proved that it is not in contradiction with the ideas of the unity of God, of His omnipotence and of His nature as the sole Creator. Ibn Rushd went on to reason that God as an infinite cause could not be proven except by positing infinite causes in circular motion, on the premise that an infinite cause must by necessity produce infinite effects. In this way the eternal rotation of the heavens is the immediate effect of God’s infinite causality. Demonstratively, Ibn Rushd proves that Aristotle’s principle of the finite force in the body is correct in all ways if that body is sublunary; but if it is a celestial body, its force is finite in one respect, infinite in another. It is finite in intensity and speed, moving just one body with a definite magnitude and with a regular fixed speed; it is also infinite in time, that is, it moves the celestial body in infinite time. Ibn Rushd tried to prove that the force of the celestial body is infinite in time in itself and by its nature in many ways, such as proving that this nature is characterized by some distinctive features: it is not composed of matter and form similar to sublunary bodies, its matter is eternal because it is simple and lacks contraries, and its form is just its circular motion.
Keywords: Philoponus, Neo-Platonism, Eternity, Celestial Body, Potentiality, Actuality, Prime Mover, Celestial Intellect.