Avicenna (c. 980 - 1037), commonly known by his Latinized name Avicenna, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived. In particular, 150 of his surviving treatises concentrate on philosophy and 40 of them concentrate on medicine. His most famous works are The Book of Healing, a vast philosophical and scientific encyclopaedia, and The Canon of Medicine, which was a standard medical text at many medieval universities. The Canon of Medicine was used as a text-book in the universities of Montpellier and Leuven as late as 1650. Avicenna's Canon of Medicine provides a complete system of medicine according to the principles of Galen (and Hippocrates). His corpus also includes writing on philosophy, astronomy, alchemy, geology, psychology, Islamic theology, logic, mathematics, physics, as well as poetry. He is regarded as the most famous and influential polymath of the Islamic Golden Age.
Al-Ghazali (1058 - 1111 )was Persian Muslim theologian, jurist, philosopher, and mystic. Ghazali has sometimes been referred to by historians as the single most influential Muslim after the Islamic prophet Muhammad. Others have cited his movement from science to faith as a detriment to Islamic scientific progress. Besides his work that successfully changed the course of Islamic philosophy. The early Islamic Neoplatonism developed on the grounds of Hellenistic philosophy, for example, was so successfully refuted by Ghazali that it never recovered - he also brought the orthodox Islam of his time in close contact with Sufism. The orthodox theologians still went their own way, and so did the mystics, but both developed a sense of mutual appreciation which ensured that no sweeping condemnation could be made by one for the practices of the other.(Wikipedia)
Averroes ( April 14, 1126 - December 10, 1198), was an Andalusian Muslim polymath; a master of Aristotelian philosophy, Islamic philosophy, Islamic theology, Maliki law and jurisprudence, logic, psychology, politics, Arabic music theory, and the sciences of medicine, astronomy, geography, mathematics, physics and celestial mechanics. He was born in Cordoba, Al Andalus, modern-day Spain, and died in exile in Marrakesh, Morocco. His school of philosophy is known as Averroism. Averroes was a defender of Aristotelian philosophy against claims from the influential Islamic theologian Ghazali who attacked philosophy so it would not become an affront to the teachings of Islam. (Wikipedia)
Chris Lowney, Chapter 13.
A Vanished World: Muslims, Christians, and Jews in Medieval Spain,
Oxford University Press (2006),