I answer that, it must be said that although the Blessed Virgin was not sanctified before her animation, because the flesh, as it is not the subject of sin, so neither is it of sanctifying grace, she was nevertheless sanctified in her very animation, that is to say, in the same moment in which it was necessary, from the common law of the sons of Adam, that guilt be in her, such that there never was, nor did she contract, original sin. The very excellence of her Son, for the purpose of not derogating from which some hold the opposite opinion, is what shows this. For [Oxon. ib. n.4] it was fitting for the most perfect Mediator, such as Christ the Lord was, to have had the most perfect act of mediating with respect to some person of whom he was Mediator: but he is not conceived to have existed as the most perfect Mediator of God and of his Mother unless he had preserved her from falling into original guilt; therefore she was preserved from being infected with original guilt. The minor is shown: [Oxon. ib.] first by comparison to God to whom he reconciles: second by comparison to the evil from which he liberates: third by comparison to the person for whom he reconciles. And the first in this way, by supposing that it was not impossible for original guilt to be prevented from being present, since it is not guilt, except contracted from another; and if that was possible, for no one did it become the Mediator to have done it than for his Mother. Therefore the argument is as follows: [Oxon. n.5] a mediator is not conceived to mediate most perfectly, or to placate someone for an offense that had to be contracted, unless he prevents the offense from being present and prevents anyone from being offended by it; for if he placates someone already offended, and sways him to remit guilt, he does not exercise the most perfect act of mediating or placating, as he would have done by preventing the offense; therefore Christ does not most perfectly reconcile or placate the Trinity for the guilt to be contracted by the sons of Adam, if he does not prevent the Trinity from being offended, on account of the inherent guilt, in some one among them. Since therefore Christ was the most perfect Mediator, it is necessary that he have altogether prevented someone from contracting original guilt: but it was not fitting that this be any other besides his most blessed Mother. — The argument under the second head: [Oxon. ib. n.6] because Christ seems to be more immediately our Repairer from original sin than from actual sin; for the necessity of the Incarnation is commonly assigned from original sin: but he was to that extent the most perfect Mediator with respect to his Mother that he preserved her from every actual sin; therefore also from original sin; especially since this original sin is a greater punishment than the lack of the Divine vision; for sin is the greatest of punishments for an intellectual nature; therefore Christ, as the most perfect Mediator, merited to take away this most heavy penalty from his Most Blessed Mother, otherwise he would not have reconciled most perfectly nor would he have been the most perfect Mediator. — The argument finally from the third. [Oxon. ib. n.7] A person who has been reconciled is not supremely obliged to his mediator unless he has from him the whole of the good which he can receive: but preservation from contracting guilt can be had through a mediator; therefore no person was supremely beholden to Christ as Mediator if he did not preserve anyone from original sin. (The minor was touched on also in article 1, and will be declared more clearly in the following articles.)
