clarify and simplify Aristotle's original text. The middle commentaries were probably written in response to his patron caliph Abu Yaqub Yusuf's complaints about the difficulty of understanding Aristotle's original texts and to help others in a similar position. The long commentaries (tafsir or sharh), or line-by-line commentaries, include the complete text of the original works with a detailed analysis of each line. The long commentaries are very detailed and contain a high degree of original thought, and were unlikely to be intended for a general audience. Only five of Aristotle's works had all three types of commentaries: Physics, Metaphysics, On the Soul, On the Heavens, and Posterior Analytics. Stand alone philosophical works Averroes also wrote stand alone philosophical treatises, including On the Intellect, On the Syllogism, On Conjunction with the Active Intellect, On Time, On the Heavenly Sphere and On the Motion of the Sphere. He also wrote several polemics: Essay on al-Farabi's Approach to Logic, as Compared to that of Aristotle, Metaphysical Questions Dealt with in the Book of Healing by Ibn Sina, and Rebuttal of Ibn Sina's Classification of Existing Entities. Islamic theology Scholarly sources, including Fakhry and the Encyclopedia of Islam, have named three works as Averroes's key writings in this area. Fasl al-Maqal ("The Decisive Treatise") is an 1178 treatise that argues for the compatibility of Islam and philosophy. Al-Kashf 'an Manahij al-Adillah ("Exposition of the Methods of Proof"), written in 1179, criticizes the theologies of the Asharites, and lays out Averroes's argument for proving the existence of God, as well as his thoughts on God's attributes and actions. The 1180 Tahafut al-Tahafut ("Incoherence of the Incoherence") is a rebuttal of al-Ghazali's (d. 1111) landmark criticism of philosophy The Incoherence of the Philosophers. It combines ideas in his commentaries and stand alone works, and uses them to respond to al-Ghazali. The work also criticizes Avicenna and his neo-Platonist tendencies, sometimes agreeing with al-Ghazali's critique against him. Medicine Averroes, who served as the royal physician at the Almohad court, wrote a number of medical treatises. The most famous was al-Kulliyat fi al-Tibb ("The General Principles of Medicine", Latinized in the west as the Colliget), written around 1162, before his appointment at court. The title of this book is the opposite of al-Juz'iyyat fi al-Tibb ("The Specificities of Medicine"), written by his friend Ibn Zuhr, and the two collaborated intending that their works complement each other. The Latin