The Incoherence of the Philosophers was written by a Persian theologian. He died 13 years before Averroes (Ibn Rushd).
Ab mid Muammad ibn Muammad al-Ghazl ( ; Arabic:        ; 1058  19 December 1111), shortened as Al-Ghazali in Arabic or Ghazali in Persian and known as Algazelus or Algazel to the Western medieval world, was a Persian theologian, jurist, philosopher, and mystic. 
Ibn Rushd (Arabic:   ; 14 April 1126  10 December 1198), full name (Arabic:        , "Ab l-Wald Muammad Ibn Amad Ibn Rushd "  ), often Latinized as Averroes ( ), was a medieval Andalusian polymath. 
The Incoherence of the Philosophers (  "Tahfut al-Falsifa" in Arabic) is the title of a landmark 11th-century work by the Persian theologian Al-Ghazali and a student of the Asharite school of Islamic theology criticizing the Avicennian school of early Islamic philosophy. 
