The dialectic of Paris prevailed over the humanism of Chartres. But if some of the first freshness of the new birth was thus lost, the end of the century saw the scholar class a recognised element in the European commonwealth. So numerous were the ‘masters’ who taught in the Paris schools that they formed themselves into guilds or corporations, from which the germ of the University of Paris and of all other transalpine universities grew. Monasticism and philosophy combined to strengthen the Church, but the spirit of revolt that had been conquered in the schools now took more popular shapes. All through the eleventh century there were found wandering teachers of strange doctrines. From the beginning of the twelfth century definitively heretical sects were crystallising round different principles of innovation. [Sidenote: Popular heresies.] For more than twenty years an unfrocked priest, Peter de Bruys, taught with powerful effect in Dauphiny and Provence. [Sidenote: Peter de Bruys.] He was an enthusiast like the old Montanists, rejecting all forms, discipline, and tradition, in favour of the living spirit, and denouncing the sacerdotal system and many of the most treasured dogmas of the Church. In 1137 or 1138, Peter was burnt alive at Saint-Gilles by the mob, whose fury he had excited by making a bonfire of crosses and pious emblems. But his followers kept together after his death, under the guidance of Henry, an outcast monk of Cluny. Peter the Venerable wrote against the Petrobrusians, and St. Bernard saw in the popularity of the young sect the malign influence of the spirit of Abelard. ‘The Catholic faith,’ he lamented, ‘is discussed in the streets and marketplaces. We have fallen upon evil times.’ His energy secured the conversion of many of the Petrobrusians. The remnant joined themselves to the new sect of the Waldenses or Vaudois. [Sidenote: Peter Valdez and the ‘Poor Men of Lyons.’]