 Al-Ghazâlî (c.1056–1111) was one of the most prominent and influential philosophers, theologians, jurists, and mystics of Sunni Islam. He was active at a time when Sunni theology had just passed through its consolidation and entered a period of intense challenges from Shiite Ismâ’îlite theology and the Arabic tradition of Aristotelian philosophy (falsafa). Al-Ghazâlî understood the importance of falsafa and developed a complex response that rejected and condemned some of its teachings, while it also allowed him to accept and apply others. Al-Ghazâlî’s critique of twenty positions of falsafa in his Incoherence of the Philosophers (Tahâfut al-falâsifa) is a significant landmark in the history of philosophy as it advances the nominalist critique of Aristotelian science developed later in 14th century Europe. On the Arabic and Muslim side al-Ghazâlî’s acceptance of demonstration (apodeixis) led to a much more refined and precise discourse on epistemology and a flowering of Aristotelian logics and metaphysics. With al-Ghazâlî begins the successful introduction of Aristotelianism or rather Avicennism into Muslim theology. After a period of appropriation of the Greek sciences in the translation movement from Greek into Arabic and the writings of the falâsifa up to Avicenna (Ibn Sînâ, c.980–1037), philosophy and the Greek sciences were “naturalized” into the discourse of kalâm and Muslim theology (Sabra 1987). Al-Ghazâlî’s approach to resolving apparent contradictions between reason and revelation was accepted by almost all later Muslim theologians and had, via the works of Averroes (Ibn Rushd, 1126–98) and Jewish authors, a significant influence on Latin medieval thinking.