William of Saint-Amour was an early figure in thirteenth-century scholasticism, chiefly notable for his withering attacks on the friars.
The pope proved sympathetic to their concerns: Innocent duly limited many of the friars' powers, and reduced the number of chairs they could legitimately occupy at the university.
Alexander was cardinal protector of the Franciscans and therefore unlikely to side with the seculars: he promptly overturned the restrictions imposed by his predecessor, allowing the friars to be readmitted to Paris.
In 1255 Pope Alexander ordered an inquiry into William's orthodoxy, resulting in his suspension from all teaching and administrative duties.
In 1256 William produced De periculis novissimorum temporum ("On the Dangers of the Final Days," or "Of the Perils of the Most Recent/Modern Times"), a vicious tirade against the friars, and the culmination of his antifraternal thought.
This ridiculed the more extreme eschatological speculations of some friars (e.g., Gerard da Burgo Santo Donnino, author of the Introductorius ad Evangelium Aeternum), who alleged that the fraternal orders would usher in the third and final age of the world, a glorious era of the Holy Spirit.
De Periculis implied that the friars would indeed be instrumental in precipitating the end of the world, but only because they would facilitate the coming of the Antichrist.
The treatise attracted written opposition from Thomas Aquinas and Albertus Magnus, both Dominican friars, and was examined by a curial committee.
The friars are variously likened to ravening wolves (lupi graves), stealers into people's homes (penetrantes domos), idlers and meddlers (otiosos et curiosos), aimless wanderers (gyrovaguos) and, most recurrently, false preachers (pseudo-praedicatores).
In Penn Szittya's phrase, this set of accusations and themes formed an enduring 'symbolic language', one that persisted among the friars' opponents for the next three centuries.
In France, William's attacks were reiterated in the Parisian disputes of 1354, when two prominent bishops delivered diatribes against the friars; they also directly stimulated the satires of Rutebeuf and Jean de Meun.
In Ireland, his arguments formed the backbone of Richard Fitzralph's Defensio Curatorum, a much-copied and widely circulated sermon of 1350.
In Scotland, Dunbar and Robert Henryson drew on William's motifs; in Germany, the Lutheran pamphleteers Johann Eberlin von Gunzburg and Heinrich Spelt made much use of his ideas.
The work of Langland, John Gower and Chaucer directly echoes De Periculis, while its key ideas were assimilated into Lollard ideology from Wyclif onwards (see especially Pierce the Ploughman's Crede).
He powerfully stigmatised one of the dominant factions in the late medieval church, providing generations of critics with an arsenal of ready-made indictments.
Critical editions of his three extant sermons and his response to Bonaventure's disputed question De mendicitate may be found in Andrew G. Traver, The Opuscula of William of Saint-Amour: The Minor Works of 1255-1256 (Munster: Aschendorff Verlag, 2003) ISBN 3-402-04014-X Critical editions of his two disputed questions may be found in Andrew G. Traver, 'William of Saint-Amour's Two Disputed Questions De quantitate eleemosynae and De valido mendicante,' Archives d’histoire doctrinale et littéraire du moyen âge 62 (1995): 295-342.