Read this: Later interpretations of Avicenna's philosophy split into three different schools; those (such as al-Tusi) who continued to apply his philosophy as a system to interpret later political events and scientific advances; those (such as al-Razi) who considered Avicenna's theological works in isolation from his wider philosophical concerns; and those (such as al-Ghazali) who selectively used parts of his philosophy to support their own attempts to gain greater spiritual insights through a variety of mystical means. It was the theological interpretation championed by those such as al-Razi which eventually came to predominate in the madrasahs.

Who's philosophy was spilt into 4 different schools?
What is the answer? (If it cannot be answered, return "unanswerable")
unanswerable