The Eternity of the World Refuted

Following Aristotle and Plotinus, Al-Farabi and Avicenna held that the world emanates necessarily and eternally from God — as light radiates from the sun without temporal beginning. To say that God created the world at a moment in time, they argued, would imply that God underwent a change, that there was a "before" the creation in which God willed differently. This is incompatible with God's simplicity and immutability.

Al-Ghazali attacks the coherence of the very concept of an eternal world created by God. If God has always willed the world, then there is no explanation for why the world began at a particular moment — but the philosophers' own position requires an eternal world, which means it never began. He also argues that an actual infinite past is philosophically incoherent, citing paradoxes about infinite series of past events.

The eternity doctrine is not merely philosophically wrong, Al-Ghazali argues, but heretical, because it denies creation ex nihilo and with it the absolute power of God. The related heresy of denying bodily resurrection follows: if the world is eternal and souls are necessarily immortal, there is no room for a divine judgment of individual persons at the end of time. Islamic orthodoxy requires temporal creation and genuine divine omnipotence.

The first three discussions of The Incoherence of the Philosophers address the eternity of the world. The charge of heresy is delivered at the end of the work.