discussion was an abomination; for the end of conversation was spiritual edification, not the advancement of knowledge; and what to strong minds might be mental gymnastics, in the case of weaker brethren caused the undermining of their faith. Against heretics of the commoner sort, such as the Petrobrusians, who impugned the whole system of the Church and appealed to the mere words of Scripture, there was only one line to be taken. But Bernard was no persecutor. During his preaching of the Crusade a monk perverted the popular excitement to an attack upon the Jews in the cities of the Rhineland: Bernard peremptorily interfered and crushed the rival preacher. Similarly with heretics. He trusted to his preaching--attested, as it was commonly supposed, by miracles--to convince the people; while the leaders when captured were subjected to monastic discipline. [Sidenote: Abailard.] But such popular forms of unbelief were merely the outcome of the speculations of subtler minds, which it was necessary to stop at the fountain-head. The arch-heretic of the time was Peter Abailard, who routed in succession two great teachers--William of Champeaux in dialectic in the great cathedral school of Paris, and Anselm of Laon, a pupil of Anselm of Canterbury, in theology. He gathered round him on the Mount of Ste. Geneviève, just outside Paris, a large band of students, in whom he inculcated his rationalistic methods. For his was a definite attempt to obtain by reason a basis for his faith. How could such teaching be allowed to continue unreproved by Bernard, who held that the sole office of the reason was to lead the mind astray? But in the height of his fame Abailard, still quite young, loved the beautiful and erudite Heloise. He abused her trust, and when she in her infatuation for his genius refused to monopolise for herself by marriage the talents which were for the service of the world, she and he both entered the monastic life. Abailard passed through several phases of this--a monk at St. Denys; a hermit gradually gathering a band of admirers round a church which they built and he dedicated to the Third Person of the Trinity, the Paraclete; and finally the abbot of a poor monastery in his own native Brittany. While an inmate of St. Denys a work of his on the Trinity was condemned at a Council at Soissons presided over by the papal legate (1121). It was twenty years before he was again subjected to the censures of the Church. But, meanwhile, he had more than once fallen foul of Bernard, and had not hesitated to flout with his gibes the one man before whom the whole of Catholic Europe bent in awestruck reverence. But the time came when Bernard, noting the spread of the Petrobrusian heresy, determined to strike at the source of these errors. He appealed for assistance to the friends of orthodoxy from the Pope downwards. Abailard determined to anticipate attack and desired to be heard before an assembly to be held at Sens (1140).