Aside from the acceptability of the doctrine of the Immaculate Conception, and its necessity or lack thereof, is the history of its development within the Roman Catholic Church. The Conception of Mary was celebrated in England from the ninth century. Eadmer was influential in its spread. The Normans suppressed the celebration but it lived on in the popular mind. It was rejected by St. [[Wikipedia:Bernard of Clairvaux|Bernard of Clairvaux]], [[Wikipedia:Alexander of Hales|Alexander of Hales]], and St. [[Wikipedia:Bonaventure|Bonaventure]] (who, teaching at Paris, called it "this foreign doctrine," indicating its association with England). [[Thomas Aquinas]] expressed questions about the subject but said that he would accept the determination of the Church (his difficulty was in seeing how Mary could be redeemed if she had not sinned).

The Oxford Franciscans [[Wikipedia:William of Ware|William of Ware]] and especially [[Wikipedia:John Duns Scotus|John Duns Scotus]] defended the doctrine despite the opposition of most scholarly opinion at the time. Scotus proposed a solution to the theological problems involved with reconciling the doctrine with the doctrine of universal redemption in Christ by arguing that Mary's immaculate conception did not remove her from redemption by Christ but rather was the result of a more perfect redemption given to her on account of her special role in salvation history. Scotus' defence of the immaculist thesis was summed up by one of his followers ''potuit, decuit ergo fecit'' (God could do it, it was fitting that he did it, and so he did it). Following his defence of the thesis, students at Paris swore to defend the thesis and the tradition grew of swearing to defend the doctrine with one's blood. Arguments ensued between the immaculist Scotists and the maculist Thomists, and the former tried to link this doctrine with that of the primacy of Christ (which says that Christ would have become man even if [[Adam and Eve|Adam]] had not sinned) since both groups reject the idea that God's plans were determined by human sin.