Abu al-Walid Muhammad ibn Rushd (1126–1198) was born in Córdoba, trained as a jurist (a Maliki qadi), physician, and philosopher, and served at the court of the Almohad caliph Abu Ya'qub Yusuf. The caliph asked him for an accessible summary of Aristotle's texts; Ibn Rushd turned the request into a lifelong project. For nearly every work of Aristotle he wrote commentary at three levels: short (talkhis), middle (jawami'), and great (tafsir). The aim was to explain Aristotle from Aristotle alone, stripping out mystical or Neoplatonic additions.

His Tahafut al-Tahafut (Incoherence of the Incoherence), written in answer to Ghazali, defends Aristotelian causation and the eternity of the world. One of his sharpest positions has been read as a 'double truth' doctrine: philosophy and revelation reach the same truth by different routes; where they appear to conflict, the sacred text must be read allegorically.

The Latin translations of his work struck Europe with immense force in the 13th century. At the University of Paris, the 'Latin Averroists' (Siger of Brabant chief among them) embraced his philosophy as a tool; on the opposing side stood Bonaventure and ultimately Thomas Aquinas. That clash made the relation between Christian faith and Greek reason Europe's central question. His influence in the Muslim world was limited; in Europe he was midwife to the redrawing of the boundary between reason and revelation. For Aquinas, Ibn Rushd is referred to simply as 'the Commentator'.