IMMACULATE CONCEPTION is the name given in the Church of Rome to the doctrine that the Virgin Mary was conceived in the womb sinlessly as Christ himself was. The first public controversy on this question arose A.D. 1140, at which time various churches, both in England and France, had begun to hold festal days in honour of the immaculate conception. Of the more important churches, that of Lyons was the first to celebrate this festival, and it was the opposition raised to it by Bernard that brought on the discussion. In the fourteenth century this doctrine was one of the points of controversy between the Dominicans and Franciscans, the two most powerful religious orders of the time.
On the side of the Franciscans great renown was acquired by the celebrated Scotus in defending the dogma, for he set himself specially to oppose Thomas Aquinas, the great oracle of the Dominicans, and hence arose the division of sects known as Thomists and Scotists. In the seventeenth century the old dispute between the Dominicans and Franciscans raged with greater fury than ever. Two kings of Spain, Philip III. and IV., sent to Rome for the express purpose of having the dispute authoritatively settled by the sovereign pontiff. These embassies were sent to three different pontiffs, Paul V., Gregory XV., and Alexander VII., but they all shrank from the task. It was obviously dangerous to decide against either of such powerful parties, and the pontiffs evaded the difficulty by declaring that the arguments of the Franciscans were of some weight, and by forbidding the Dominicans to attack the Franciscan doctrines publicly. Notwithstanding this vacillation on the part of the above-named pontiffs, the question seems to have been virtually settled in the fifth session of the Council of Trent, where it is said that the "Blessed and Immaculate Virgin Mary" is excepted from the decree concerning original sin. However, as the controversy continued from time to time to disturb the Church, it was finally decreed by the bull of Pio Nono, 8th December 1854, that the doctrine of the Immaculate Conception is an article of faith of the Church of Rome.