In the work of Thomas, Bonaventure and their contemporaries, theistic arguments served to open up the space within shared doctrines where differences of interpretation could be articulated and contested. For the Dominicans, the natural state of the human mind with respect to the knowledge of God is one of ignorance, for Matthew of Acquasparta, ignorance of God's existence lies in a defect of the intellect's natural powers. Like Thomas Aquinas, Richard interprets John of Damascus as referring to an innate power to seek God through creatures, not that the knowledge of God is already inserted within the soul like a self-evident proposition. The most significant part of William of Ware's treatment of the natural knowledge of God is his introduction of a pre-requisite for any proof of God's existence. To prove the existence of God, he argues that it is necessary to arrive at a being infinite in power and in essence.