Much of my current research is on the topic of radicalization, how it happens and how it can be prevented or fixed. I recently had the opportunity to present some ideas (which will be the foundation of another writing project) at the Universal Tolerance Forum.
You can find the skeleton description of the process here - more material coming soon.
In my search in early Islamic intellectual history I noticed that early interpretations about free will were philosophically libertarian. In a free will context, "Libertarian" means the position that human beings have true free will, and a rejection of determinism. Pre-Islamic Quraysh, on the other hand, were hard determinists. They even commonly blamed their own immorality and excesses on fate. The Umayyads (direct as well as cultural descendants of Quraysh) would later seek to promote hard determinism under various guises. Umayyads (especially in their middle period) referred to fatalism in order to justify their own tyranny and to discourage rebellion.
I have been immersed in the study of Islamic intellectual history for over 2 years now. It has been rewarding and transformative, but also alienating. It's clear to me that Islamic brilliance peaked in the 3rd century AH, then slipped (with occasional bright flashes and sharp catastrophes). I won't comment on the reasons of decline because that was never the purpose of my study. I find most debates on this boring now. My main concern was (and still is) the ideas that led to brilliance, whose loss lead to decline.