The conservative Sunni Islamic theologian and Sufi al-Ghazali (1058 – 1111 CE) wrote a famous denunciation of philosophers in Islam, called The Incoherence of the Philosophers. (In Latin, “incoherence” was rendered as “destruction”.) This was a classic statement of the occasionalist doctrine that everything that happens is directly caused by the will of God, and all other explanations are illusory. This is a kind of consequence of strong theological voluntarism. Spurred by the voluntarism of Descartes, many 17th century Cartesians later adopted occasionalist views. Related voluntarist views were earlier strongly voiced by Philo of Alexandria, and later in the Latin West by Franciscan theologians such as Duns Scotus and William of Occam.

The great Aristotelian commentator Ibn Rushd or Averroes responded to Ghazali on behalf of the philosophers, in a work entitled Incoherence of the Incoherence. An Islamic jurist as well as a philosopher, he argued in another work never translated to Latin that the Koran effectively tells those who are capable of rational understanding to study philosophy. In his response to Ghazali, Averroes pointed out that Ghazali’s argument made inferences from the empirical to the divine. Ghazali had said that everything that happens is deliberated and knowingly chosen by God. This actually Aristotelian terminology of deliberation and choice applies to empirical agents, insofar as they want and lack something. Averroes responded that God lacks nothing, and therefore does not choose or deliberate like a human would.

This small piece of a much larger argument is illustrative of a typical contrast. Broadly Aristotelian and neoplatonic views both emphasized the eternity of the divine as part of its perfection. They also took “secondary” causes very seriously, because they took something like Hegelian mediation seriously. Conversely, if God were directly responsible (causally or morally) for everything that happens, this would abolish all causal or moral responsibility of all other beings, and indeed all distinction whatsoever. (See also Strong Omnipotence.)