The formation of an orthodox scholasticism within the Muslim church appears as a development spread over the 4th-5th centuries of the Hijra (10-11 cent. A.D.), and is in three strata associated with the three leaders, al-Ash`ari, al-Baqilani, and al-Ghazali. Such a development, of course, is principally of interest for the internal history of Islam and the evolution of Muslim theology, but it had its influence also on the transmission of Arabic thought to Latin Christendom in two ways: (i.) directly, in that al-Ghazali was established as one of the great Arabic authorities when the Latins began to study the interpreters of Aristotle, and his teaching is quoted by St. Thomas Aquinas and other scholastic writers; and (ii.) indirectly, because a considerable part of the work of Ibn Rushd (Averroes) takes the form of controversy against the followers of al-Ghazali; his _Destruction of the Destruction_, for example, is a refutation of al-Ghazali’s _Destruction of the Philosophers_. It thus becomes imperative to know something about the position and teaching of al-Ghazali and the influences which prepared the way for his work. Such a movement as orthodox scholasticism was inevitable. The position at the end of the third century was quite impossible. The orthodox Muslim adhered strictly to tradition, and entirely refused to admit “innovation” (_bid`a_): he had been forced into this position as a reaction against his earlier ready acceptance of Plato and Aristotle as inspired teachers, for the later errors of the Mu`tazilites showed what extremely dangerous conclusions could be drawn by those who came under Hellenistic influence, and the more accurately the Greek philosophers were studied the worse the heresies gathered from them. Orthodox thought held itself carefully aloof from the Mu`tazilites and philosophers on the one side, and from the Shi`ites and Sufis on the other, confining itself to the safe studies of Qur´an exegesis, tradition, and the canon law in which at Baghdad the reactionary influence of Ibn Hanbal was predominant. The whole of the third century had been a time of reaction on the part of the orthodox, very largely due to the unfortunate attempt of al-Ma´mun to force rationalism on his subjects. Al-Ghazali tells us in his “Confessions” that some sincere Muslims felt themselves bound to reject all the exact sciences as of dangerous tendency, and so repudiated scientific theories as to eclipses of the sun and moon. All speculation lay under a ban, because it led to “innovation” in belief or in practice; it was contrary to orthodoxy to use the methods of Greek philosophy to prove revealed doctrine as much as it was to impugn it, for both alike were innovations on the traditional usage; nothing was known of spiritual matters save what is actually stated in the Qur´an and tradition, and from this nothing could be deduced by the use of argument, for logic itself was a Greek innovation, at least as applied to theology: only