The Incoherence of the Philosophers

A polemical work in twenty discussions in which al-Ghazālī, then a leading teacher in Baghdad, examines the metaphysics of the philosophers, above all Ibn Sīnā. His stated aim is not to defend a doctrine of his own but to show that the philosophers fail to demonstrate their claims by their own standards of proof. He challenges their arguments for the eternity of the world, their proofs of God's unity and simplicity, their claim that the heavens are living beings, and their account of the soul. The seventeenth discussion, on causation, argues that the link between what we call a cause and its effect is not necessary: when fire touches cotton, the burning is created by God, and we only observe that one follows the other. In the conclusion he judges three positions to be unbelief: the eternity of the world, the claim that God does not know particulars, and the denial of bodily resurrection.

It is the most famous challenge to philosophy in Islamic history, and its argument about cause and effect raises Hume's doubts about necessary connection centuries before Hume.