It is admitted that the doctrine as defined by Pius IX was not explicitly mooted before the 12th century. It is also agreed that "no direct or categorical and stringent proof of the dogma can be brought forward from Scripture". But it is claimed that the doctrine is implicitly contained in the teaching of the Fathers. Their expressions on the subject of the sinlessness of Mary are, it is pointed out, so ample and so absolute that they must be taken to include original sin as well as actual. Thus in the first five centuries such epithets as "in every respect holy", "in all things unstained", "super-innocent", and "singularly holy" are applied to her; she is compared to Eve before the fall, as ancestress of a redeemed people; she is "the earth before it was accursed". The well-known words of St. Augustine (d. 430) may be cited: "As regards the mother of God," he says, "I will not allow any question whatever of sin." It is true that he is here speaking directly of actual or personal sin. But his argument is that all men are sinners; that they are so through original depravity; that this original depravity may be overcome by the grace of God, and he adds that he does not know but that Mary may have had sufficient grace to overcome sin "of every sort" (omni ex parte).

What proof do some believe is offered as to proof of Mary being the ultimate concept of pure?