A final stage in possible developments was reached in the twelfth century in the institution of a feast in honour of the conception of the Blessed Virgin. Hitherto it had been supposed by Christian writers, notably by St. Anselm, that the Mother of the Lord had been conceived as others. Towards the middle of the twelfth century some Canons of Lyons evolved the theory that she was conceived already sinless in her mother's womb. St. Bernard strenuously opposed this notion of her immaculate conception, pointing out that the supposition involved in the theory could not logically stop with the Virgin herself, but must be applied to her parents and so to each of their ancestors in turn in an endless series. Nor was St. Bernard alone in his objection: indeed, nearly all the chief theologians of the thirteenth century, including Thomas Aquinas, declared that there was no warrant of Scripture for the theory. But notwithstanding this criticism, the festival won its way to recognition. Those who kept it, however, declared that it was merely the conception which they celebrated; and St. Thomas interpreting this to denote the sanctification, was of opinion that such a celebration was not to be entirely reprobated. It was Duns Scotus who first among the schoolmen defended the theory of the immaculate conception, but in moderate language; and his Franciscan followers, who at a General Council of the Order in 1263 had admitted the festival among some other new occasions to be observed, in the course of the fourteenth century adopted it as a distinctive doctrine. CHAPTER XII HERESIES [Sidenote: Cause of heresy.] It was not until the thirteenth century that the Church had to face that spirit of scepticism or anti-religious feeling which is the chief bug-bear of modern Christianity. Her elaborate organisation and the gradual development of her own dogmatic position enabled her to deal with individual writers of a speculative turn like Berengar or Abailard. Nor were these in any sense anti-Christian. But they were the inciters to heresy; and a real danger to the Church lay in the filtering down of intellectual speculations to ignorant classes, by whom they would be transformed into weapons against the fundamental doctrines of the Christian faith. Indeed, from the eleventh century onward the Church was constantly threatened by heresy of a popular kind, which tended to develop into schism. And for this she had to thank not only the growing materialisation of her doctrine, but even more the worldly life of her ministers. Unpalatable doctrines may commend themselves by the pure lives which profess to be founded on them; but evil doing carries no persuasion to others. [Sidenote: Two kinds of heretics.]