THE SCHOOLMEN Aquinas remained in Paris for three years, lecturing on the book of Isaiah and the Gospel of St Matthew As a professor it was his duty to oversee the formal disputations of the bachelors, and we possess the text of the disputations over which he presided, called, after the topic of the Wrst of them, Quaestiones Disputatae (‘Disputed Questions on Truth’) In fact they range over many diVerent topics: truth and the knowledge of truth in God, angels, and men; providence and predestination; grace and justiWcation; reason, conscience, and free will; emotion, trances, prophecy, education, and many other topics The collection consists of 253 individual disputations, called ‘articles’ in the editions, and grouped by themes into twentynine ‘questions’ The text of the series amounts to over half a million words In addition to these structured disputations the medieval curriculum imposed on masters the duty of undertaking a number of ‘quodlibetical’ disputations These were impromptu discussions in which any member of the audience could raise a question on any topic They were held in Advent and Lent: no doubt they were a penitential experience for the master Of the quodlibets that survive from Aquinas’ Paris period, some concern topical issues related to the controversy over the mendicant orders: for instance, the question ‘Are friars obliged to perform manual labour?’ Others are of less immediate impact, such as ‘Are there real worms in hell?’ A Wnal legacy of this time is an unWnished commentary on Boethius’ On the Trinity, which discusses the relationship between natural science, mathematics, and metaphysics, ranging these disciplines in a hierarchy of increasing abstraction from matter In 1259 Aquinas gave up his Paris professorship and spent some time in Italy When Urban IV became pope in 1261, the papal court moved to Orvieto, and St Thomas went there too During the early 1260s he was to be found teaching at Orvieto, Rome, and Viterbo, and mingling with the scholars, diplomats, and missionaries in attendance on the Pope At the court of Urban IV he met William of Moerbeke, the most accurate of the translators of Aristotle, and began a fruitful association which was to result in a magniWcent series of commentaries on the philosopher’s major works The saint was also employed by Pope Urban as a writer of prayers and hymns, especially for the liturgy of the new feast of Corpus Christi This was instituted in 1264 in honour of the sacrament of the Eucharist, in which, according to Catholic belief, bread and wine were changed into the 66