Abu al-Husayn al-Basri

Abu'l-Husayn al-Basri (died 436/1044) was a Mu'tazilite faqih (expert in Islamic jurisprudence) and theologian (mutakallim). He wrote al-Mu'tamid fi Usul al-Fiqh, a major source of influence in the field of usul until Fakhr al-Din al-Razi's al-Mahsul fi 'Ilm al-Usul.

He was a physician as well as a disciple of the Qadi Abd al-Jabbar in Rey. He challenged some of his master's teaching and eventually compiled a huge (two volumes; 1500 pages) critical review of the arguments and proofs used in Islamic Scholastic Theology . This he summarised in al Mu'tamad "The Reliable". He including a critique of the qualifications a scholar of Islamic law needed to practice. His theological works were generally handed down among students of medicine and it was a century before his teaching was revived and espoused by the Mu'tazili scholar Mahmud b. al-Malahimi in Khorezm in Central Asia where they gained recognition as a school of Mu'tazili theology.