Abu'l Husayn al-Basri

Abu'l-Husayn al-Basri was a Mu'tazilite jurist, physician and theologian. He wrote al-Mu'tamad fi Usul al-Fiqh, a major source of influence in informing the foundations of Islamic jurisprudence until Fakhr al-Din al-Razi's al-Mahsul fi 'Ilm al-Usul.