With the depredations of the Mongols (exterminating whole populations of conquered people) Islam took a turn to the right. With their cities gone they had become an agrarian culture, inevitably conservative. (Have you ever been in the 'country'?)
"By the 15th century it was agreed that the ulama (the learned men, the guardians of the legal and religious traditions) could no longer use their own independent judgment (ijtihad) in creative legislation. [the gates were closed]. Moslems were obliged to conform to the rulings of past authorities" (Armstrong, Islam 100).
A type(!) that we Christians are all too familiar with:
item: CE 325 (the Council of Nicea closed the canon)
item: Calvin has Michael Servetus executed
item: Mohammed was declared to be the last prophet (not originally in the Koran, I'm told).
item: Revelation 22:18-19
item: the 'country preacher': "the King James Version was good enough for Jesus and the apostles; it's good enough for me."
item: strict constructionism (The problem with that is it's only the judge's opponents whose ruling must be struck down.)
There have always been 'conservatives' who would allow no change except their own vision.
"But there were ulama who refused to accept the closing of the 'gates of itjihad" (103). Ah, yes! the iconoclasts; the heretics!
And there were some who turned back to the past to retrieve the wisdom that had been thrown away in the march to the future:
Some have had good reason to turn back to primitive Christianity, that is to say when contemporary Christianity has become hopelessly corrupt.
Blake has been considered an idealist and a futurist; few people realize that he was a great traditionalist. He retrieved for us all sorts of medieval stuff gone into limbo.
Sooner or later we all have to go back, dear friends:
" The ancient tradition that the world will be consumed in fire at the end of six thousand years is true, as I have heard from Hell.
For the cherub with his flaming sword is hereby commanded to leave his guard at the tree of life, and when he does, the whole creation will be consumed and appear infinite and holy whereas it now appears finite & corrupt."
Marriage of heaven and Hell.
Look at the pictures.