Reginald Garrigou-Lagrange O.P. The Three Ages of Interior Life
At the beginning of a treatise on the interior life, it is important to get a high idea of sanctifying grace; Protestantism, following several nominalists of the fourteenth century, has lost the conception of it. In Luther's opinion, man is justified not by a new infused life, but by the exterior imputation of the merits of Christ, in such a way that he is not interiorly changed and that it is not necessary for his salvation that he observe the precept of the love of God above all else. Such an opinion is a radical misconception of the interior life spoken of in the Gospel. This lamentable doctrine was prepared by that of the nominalists, who said that grace is a gift which is not essentially supernatural, but which morally gives a right to eternal life, like paper money which, though only paper, gives a right, by reason of a legal institution, to receive money. This doctrine constituted the negation of the essentially supernatural life; it was a failure to recognize the very essence of grace and of the theological virtues.
Well, so what if what Luther teaches about Salvation and Sanctification is worth less than the insipidity of his fart jokes, Luther is the Heresiarch now to be "studied" so as to make him palatable to Catholics and it is just another car attached to the ecumenical train that is inexorably drawing closer to the last stop on the trip - Indifferentism Central.
ABS jumped off this train a long time ago...