I didn't understand what you said
Okay, so postmodernism is a reaction to modernity, right? So the postindustrial cultural results of romantacism. The ideas that came from modernity features themes of cultural fragmentation, social evils and narrative authority. This lead to many consistent ideas of contomporary nationalism and historicism today. People who lead the bedrock of these ideas are people like Hume, Locke, Marx, Comte and Freud.
Postmodernists either critique or reject modernity. Ideas such as historical innevitability due to one consistent metanarrative of a given material dialectic are picked apart by postmodernists, this is why postmodernism is known for its fluid theory of truth.
I don't see Islam fostering this. It has a metanarrative - there is no god but God and Mohammed is his prophet. It has its material dialectic - the scripture as well as the Qur'an, Hadit and Sunnah. It has historical innevitability - prophecy. It cannot function from a postmodernist view point because old world religions don't even have basis in modernity, they're more fundimental than those.
That's not quite true.
That region did develop mathematics and other disciplines. However, when Islam and Sharia Law fully permeated that area, science, math and other technological advances, all but came to a full stop over time. If they foster such endeavors, as you imply, they should be ln the tops of Nobel Laureates list. They're not.
If you don't think that the philosophy of Islam and Sharia Law played a major role in this, then what else could it be? I'd really like to know.
So the answer is neither. Different cultures foster different advancements due to their material conditions allowing them so. So for when Islamicate societies were at their zenith, this was during the rule of the Abbasids who benefitted off the back of the expanse of the Umayads which gave not only access to the past Greek, Persian and Arab literature but also from India and China in the East with Western Rome from the West. The Middle East is also primely positioned for wealth, them benefitting from the Silk Road and the Indian Ocean Trade. The wealth from the Swahili Coast and the Mali Empire to the Majapahit Archepelego or the Song Dynasty - all of their mighty wealth flowed through their hands. They had the resources and the material to sustain advancement so fast that such speed wouldn't be seen until industrialisation.
They lost this mostly after the the short lived Mongol Empire fell apart into the Chagatai Khanate, the Golden Horde, the Yuan Dynasty and the Ilkhanate, because political instability doesn't foster the same advancement. I mean they still advnaced, the descendants of these Turko-Mongol empires would be known as the Gun Powder states - the Ottomons, the Murgals and the Safavids, but this slowed. Actually, this is considered one of the driving forces of European colonialism as now cut off from the east by these Gunpowder States, the English, Portuguese, Spanish and Dutch would seek a means back into the Indian Ocean trade.
So why is it now that Nobel Laureates now come from North America and Western Europe primarily? Because they have the material and the resource to do so. Now you'll be wondering how little I described the Islamic scriptural basis that fostered that development because it doesn't matter. I'm not inherently an adopted father but were the materials and resources in place, such as me adopting an orphan, I would literally be fostering that child. Likewise, Islam did foster advancement because it had the material and resources to do so. Right now, liberalism is fostering advancement and most could probably tell, I'm not a liberal. However, it's oviously fostering advancement because it has the material and resources as it is the primary ideology of the developed world.
BTW, a lot of the contributions to literuature in physics from the Islamic world has been Persian. Why? Because Iran has been investing greatly in physicists as it has a material reason to develop geopolitical power by developing its technology in areas such as thermonuclear physics (to the surprise of no one). It's not because it's an Shia republic, it's not despite being a Shia republic, it just is a Shia republic developing in the field of physics.