The Bactra Review   Avram Davidson's Afterlife
The quotation is actually a paraphrase provided by Barry S. Kogan on p. 155 of his Averroes and the Metaphysics of Causation (Albany, NY: SUNY Press, 1985). I have not been able to lay hands on a copy of al-Ghazali's Incoherence to provide a verbatim statement, which I recall as being verbally quite striking.