Historically, Islamic philosophers (as they were then called) took works from the greek philosophers before them and expanded upon it. Then a few other philosphers who did not like people learning from non-muslims leaned hard into fundamentalism and you now have the kind of Islam (Salafist/Wahhabism) that exists today, e.g. Saudi Arabia

The Mongols opened the door to fundamentalism, but it didn't have to go that way. The sack of Baghdad is a simplification

Read up on Al Ghazali, it is eye-opening: https://en.wikipedia.org/wiki/Al-Ghazali