 His theology was systematically Aristotelian, although not uncritically so, and he was the first theologian to attempt to reconcile Aristotle with Christian doctrine, and especially with the teachings of Augustine of Hippo.The Aristotelian texts which were then available in Western Europe were few in number and mostly Arab translations.William sought to rescue Aristotle from the Arabians and worked to refute certain doctrines, such as the eternality of the world and the heresy of Catharism.