The Incoherence of the Incoherence

Ibn Rushd's point-by-point reply to al-Ghazālī's Incoherence of the Philosophers, written some eighty-five years after it. He quotes al-Ghazālī passage by passage and answers each in turn. He defends the eternity of the world, arguing that an eternal and unchanging agent must act eternally, so that the world is perpetually created rather than created at a first moment. On causation he replies that to deny the natural powers of things is to deny knowledge itself, since knowing something means knowing its causes. He argues that God's knowledge is neither universal nor particular in the human sense, because it is the cause of things rather than caused by them. Throughout, Ibn Rushd also criticises Ibn Sīnā wherever he thinks Avicenna strayed from Aristotle, and he complains that al-Ghazālī used dialectical rather than demonstrative arguments and spread before the public debates that should have stayed among the learned.

It is the great defence of Aristotelian reason in Islamic philosophy, and read with al-Ghazālī it gives one of the best-documented debates on creation, causation and God's knowledge in any tradition.