It is quite bold to say that there was ONE man behind Islamic fundementalism, however it is true. Abu Hamid Al Ghazali was a Persian theologist who put an end to the Golden Age of Arabic/Persian science. Lived between 1055 to 1111 AD, he took the Islamic world back to the dark ages with the help of the vizier of Seljuq dynasy of Persia, Nizam Al Mulk. Nizam Al Mulk ,who established religious colleges, institutionalised religious studies and laws and created lucrative career for Mullahs and preachers, which has prolonged until today.
Al Ghazali started bashing science, blaming it to be harful to Muslims’ faith. As the brain of Nizamiye, Ghazali knew that religion wouldn’t stand a chance against logic and science, and its weakness would lead to Saljuq’s dawn. Thus, he criticized Avicenna, Al Farabi and Aristotle’s philosophy and wrote a book on the incoherence of philosophy and science, claiming that religion was the ultimate answer. (As you might know, Avicenna is the most influential physician of the Islamic Golden Age and the father of the early modern medicine, and Al Farabi was a philosopher and mathematician.)
Al Ghazali’s fear and hatred toward logic and science was so fierce that he accused mathematics of being the Satan’s work! Al Ghazali , in his effort to bash science, claimed that everything happened becuase of God’s will and nothing would happen if God didn’t will it to. As an example, he explained that cotton burned near fire had not happened because of a natural law or an independent law of cause, but it only happened because God willed it to!
His numerous publications and claims led to the end of the Islamic Golden Age, an era which had not started because of the religion ,despite its name, but ended because of the religion.
Al Ghazali and Nizam Al Mulk can be considered as the most influential people in shaping today’s Islam world, particularly Iran. The establishment of religious studies, creating the career of muslim clergies and the shaming of science have all led to what we have today as Islam. Iran as an Islamic country respects Al Ghazali by calling him Imam Ghazali and considers him as a renewer of the faith. It’s not surprising as Mullahs and Ayatollahs rule the theocracy of Iran.