 He was an early infallibilist; the concept of papal infallibility is thought to occur first in a work he wrote concerning the conflict of Pope John XXII (1316–34) and the Franciscan Spirituals.It is said that he adapted this doctrine to papal needs, rather than originating it, and before 1328.He was a leading member of a small group of infallibilists at the court of Pope John XXII.