I just came across this great website: al-Ghazali's Website. al-Ghazali was the brilliant 12th century Sufi who gave a resoundingly effective response to Islamic philosophy as it was being done. al-Ghazali is famous for his occasionalism, presented in The Incoherence of the Philosophers, which is one of the topics to which Averroes had to respond in his Incoherence of the Incoherence.
For his illuminationist response to the threat of skepticism, see here.
