This is what an autocracy or kingship does.
Imam Raghib Al-Isphahani of Persia (?-1108) was beheaded during the Abbasid rule. (Mirza Hairat Dehlawi in his "Shamme Hairat")
Mu'tazilah or Mu'tazilites (Rationalists) like Abu Qasim Balakhi were the 9th to 11th century versions of Imam Raghib Isfahani, Mufti 'Abde Rabbuhu, Radha al-Rashid, Syed Jamaluddin Afghani, Sir Syed Ahmad Khan, Allama Inayatullah Khan Al-Mashriqi, Allama Muhammad Iqbal and Allama G.A. Parwez of the 18th, 19th and 20th centuries. Allamas Tamanna 'Imadi and Habib-ur-Rahman Kandhalvi and Dr Ghulam Jeelani Barq plus Mirza Hairat Dehlawi were rationalists or Mu'tazilites of the 20th century as well.
It was a Day of great misfortune for Muslims when the Abbassid royal courts banned the Mu'tazilah, crucified them and burned their treasures of knowledge, and strongly favored the Ash'aries (Salafies) who shunned reason as innovation (bid'ah) in religion. The Ash'arites took their stance on a fabricated Hadith, "Every innovation (renewed thinking in religion) is misguidance, and every misguidance abides in Hellfire."
It is interesting to dissect the term Mu'tazilah which derives from I'tizaal meaning standing aloof. The name Mu'tazilah was given to those who 'stood aloof, in other words, excommunicated. Anyone trying to exercise reason in religion was so named. Hence, the gateway to learning and scientific inquiry was closed shut for Muslims.
A victory of the Mu'tazilites could have seen the Muslims centuries ahead of Europe in science and technology.