This welcome edition is the first of the volumes which will present the complete sermons of the early thirteenth-century theological master and bishop of Paris, William of Auvergne. These 135 sermons De tempore are the first tranche of 324, which will eventually be joined by another 120 sermons De sanctis and 113 De communi sanctorum et de occasionibus. Even this grand total of 557 sermons does not quite represent the sum of Morenzoni's editing achievement: nineteen sermons exist in two versions, and three survive in three; all will be printed, making 582 sermons in all. Morenzoni gamely begins by quoting the doyen of sermon studies, L.-J. Bataillon, on the relative pointlessness of any complete edition of one preacher's output: Bataillon argued that a better method would be to print thematic volumes, using the work of several preachers to illustrate the same subject or liturgical season. But if anyone is the exception to prove Bataillon's rule, it must surely be William of Auvergne – an interesting man living at the centre of interesting times – and readers will be grateful that Morenzoni has chosen to ignore Bataillon's advice. This edition is the first printing for the great majority of the sermons since those published in the seventeenth-century edition of William's Opera omnia (available in a useful facsimile reprint) have long been known to be by William Peraldus. Moreover, although almost all the sermons are contained in six important thirteenth-century manuscripts of contemporary sermons bequeathed by Robert of Sorbon to his eponymous college, and now kept in the Bibliothèque nationale in Paris, the highly restrictive policy of the BnF's current manuscript department means that even Morenzoni (as he notes) was not able to consult the originals as fully as he would have liked. The sermons are uniform neither in length nor completeness, and we do not know what state of production or reception any represents. Some are reportationes; others may well be preacher's personal notes, but whether notes for writing or notes for preaching from is unclear. Many show the marks of an oral-aural culture, including a Latin syntax and vocabulary influenced by William's vernacular French: at least some of the sermons seem to have been given in French to lay people. What is impressive about William, however, is his constant sense of audience, and his adaptation of language to the particular preaching situation. William is (in all his works) aware of the explanatory power of the telling example and the illuminating metaphor – the medieval similitudo. Instead of reading his biblical text according to the spiritual senses of Scripture, he transforms it with down-to-earth ‘similitudes’, giving the text a context that his hearers would understand – literally, speaking his audience's language. The drunks, liars, absentee fathers, crooked judges and swingeing landlords are all there. I look forward to volume ii with pleasure.