In spite of uncertainties surrounding the precise date of composition, the thirteenth-century prose romance known in the modern edition as Le Haut Livre du Graal, or Perlesvaus, is unquestionably contemporary with a period during which, as Caroline Bynum has commented, ‘many different discourse communities […] were newly and explicitly concerned with the question of change’. Moreover, the very concept of change itself ‘tended to change in the years around 1200’; the works of Aristotle, the keystone of medieval philosophy, were at that time in the process of being rediscovered, translated and enthusiastically glossed by commentators. The Philosopher's discussions of the nature of man, and of potency and act in the relationship between body and soul, were frequently at odds with the teachings of the Church, and the dissemination of his natural philosophy in any form of public or private lecture was banned in Paris by the Provincial Council of Sens in 1210. However, the proscription was gradually eroded, so that by 1255 ‘all the known works of Aristotle […] were required in the arts faculty of the University of Paris’. The years around the composition and first readings of the Perlesvaus therefore represented a time of radical evolution in philosophies of change and the pertinence of such concepts to man and his identity.