on: The Decline of Islamic Scientific Thought: Don't Blame It on al-Ghazali, by Hassan Hassan
I appreciate your comment on the essay, although I have reservations about the use of language. The text didn't say anything about Batiniyya being an "offspring of the Shia".
In my understanding, you seem to ascribe to the traditional reading of the schools' system of education, which is familiar and widespread. "The diversity of scholars, the vibrant debates and the reliance on persuasion in dealing with religious differences". But the point of my essay is to dispute all that.
Certainly, throughout Islamic history up until now, there have always been bright scholars who existed within the most regressive systems (such as in Taliban Afghanistan or Wahhabi Saudi Arabia). Naming Khayyam as an example of a bright scientist does not challenge the argument.
It is worth emphasising that the nizamiyyat lasted for centuries and took decades to take effect, in that people shifted towards religion at the expense of independent inquiry and from their schools to the Shafi school. Modern Muslim scholars praise that system for the spread of Sunni Islam and the retreat of Batini thought.
Notice that the names you mentioned, especially the scientists ones, are the first generation scholars in the Nizamiyat; they had been brilliant scholars just like al-Ghazali but then that is exactly my point – a seismic shift towards religion was caused by the Nizami government at the time. As you said, the Nizamiyyat were a "cultural revolution" but you seem to miss their impact.
The idea that Shafi school as the school of choice for the Nizamiyyat is well-established. I quote, as an example, one scholar who lived then saying scholars from different schools were 'converting' to Shafi school for the career.