As soon as the "Free Will" was published, Erasmus hastened, as usual, to justify himself by writing in all directions to the persons whose approval was of most value to him,—to Henry VIII., Wolsey, and Fisher in England, to Melanchthon and Duke George in Germany, and to Aleander in Italy. He represents the work as a proof of his courage—"a bold deed in Germany," he says to Wolsey, while to Aleander he complains that enemies of his in Italy are abusing him for unsound scholarship.
"They call me 'Errasmus' in Rome, as if your writers had never made a mistake. They say I am unfriendly to Italy, whereas no one speaks more heartily than I of the genius of the Italians.... I have no doubt that you and I would get on beautifully, if we could only live together."
Luther waited a full year before replying to the Diatribe. It was a year of especial trial to him, for within those months it seemed as if the worst prophecies of his worst enemies were being fulfilled. All the social and economic restlessness of the time was beginning to make use of his teaching as a justification for revolt against the existing order of society. Wholly against his will he found himself held responsible for confusions he abhorred and for doctrines which seemed to him worse, if possible, than those he had undertaken to combat. His immediate duty was to clear himself of these imputations; to show how utterly foreign to his spirit and his aims were the theology of Carlstadt, the communistic speculations of Münzer, and the revolutionary radicalism of the peasant leaders. He accomplished this for all who were able to follow his argumentation in the remarkable series of pamphlets published in 1524 and 1525. Then he returned to the assault of Erasmus. The most striking quality of the long and laboured treatise, De servo arbitrio,[158] with which he replied to the Diatribe, is its perfect frankness. Indeed Luther was almost compelled to frankness by his detestation of what seemed to him the perilously shifty method of his opponent. Erasmus had deprecated violence; Luther reminds him that no great good ever came into the world without commotion and overturn of an existing order. Christ came, not to send peace, but a sword. Erasmus had said that true things were not to be uttered at all times and had given certain illustrations; Luther disposes of this point by showing that the things proposed in these illustrations were not true and therefore, of course, ought not to be told at any time. Erasmus had asked: "If there is no freedom of will, who will try to amend his life?" Luther frankly replied, "No man. No man can. The elect will be amended by the divine spirit; the rest will perish unamended." Erasmus had said that a door would be opened to all iniquity by this doctrine. Luther says: "So be it; that is a part of the evil that is to be borne; but at the same time there is opened to the elect a door to salvation, an entrance into heaven, a way to God."
On the crucial point of authority for faith, Erasmus had especially assailed what seemed to him the vague and uncertain evidence of "the Spirit." Luther replies that he is far enough from agreeing with those whose sole reliance is upon the "Spirit," of which they boast. He has had a bitter enough fight with them for a year past. In the same way he has been attacking the papacy because there one is always hearing that the Scriptures are obscure and ambiguous, and that we ought to seek at Rome for the interpreting Spirit,—the most disastrous thing possible.
"Now we hold this, that spirits are to be tried and proved by a twofold judgment; the one an internal, whereby a man, enlightened by the Holy Spirit or by a special gift of God may, so far as he and his own salvation are concerned, decide with the utmost certainty and distinguish the doctrines and opinions of all men. As is written [1 Cor. ii. 15.], 'the spiritual man judgeth all things, but is judged by no man.' This is an essential part of faith, and is necessary for everyone, even for a private Christian. This is what we have called above the internal clearness of Holy Scripture and is perhaps what those persons meant who replied to you, that all things were to be decided by the judgment of the Spirit. But this kind of judgment cannot avail for another person, and is not in question here; for no one, I believe, can doubt that it stands as I have said.
"Therefore there is a second kind of judgment, an external, whereby, not only for ourselves but for others and as regards the salvation of others, we may most surely judge the spirits and opinions of all men. This judgment belongs to the public ministry of the Word and to the external office and especially to the leaders and heralds of the Word. This we make use of when we strengthen the weak in the faith and confute our opponents. This we have called above the 'external clearness of Scripture.' And so we say that all spirits are to be tried in the sight of the Church with Scripture as the judge."
After this long introduction, Luther proceeds to take up, one after another, Erasmus' references to Scripture, and to show that he has misunderstood them because he has applied to them a false principle of judgment. We are not concerned with this theological fencing. Our interest is in the attitude of the two men towards the ultimate question of authority. Erasmus, the "individual," the man of the Renaissance, the apostle of light, the fearless critic of evils in Church and society, approaches this great doctrinal question with the timidity of a scholastic, and refers it finally to the judgment of the great authorities of the Church. Luther, the man of feeling, the thinker who only prayed to be instructed, who gloried in being the slave of a higher will, comes out here in reality as a champion of the boldest liberty of human judgment. He would settle all things by Scripture, but he would read his Scripture with his own eyes and interpret it by the light of that evidence of the Spirit which he and he alone could read for himself. His tone is one of mingled humility and arrogance, but we have no reason to question his sincerity in either character. His arrogance was that of a man who felt with Paul: "Woe is unto me if I preach not the Gospel." He closes, as he began, by praising Erasmus' learning, thanking him for having gone straight at the heart of the question, instead of worrying him, as others were doing, "about the papacy, purgatory, indulgences, and such nonsense," and warning him that henceforth he had better stick to his trade of literature and let theology alone.
By the year 1525 the Lutheran doctrine may be regarded as substantially complete, in the form which it was to take in the Augsburg Confession of 1530. Erasmus had indeed, as Luther said, gone straight to the point by which that doctrine must stand or fall, and in rejecting it he had made it impossible for anyone to rank him with the reforming party. At the same time he had shown how completely he was out of sympathy, even theologically, with the system of salvation by bona opera, which the Church was trying to maintain. More than ever therefore he found himself out of tune with both parties and, since all the world was now rapidly ranging itself on one side or the other, he experienced a growing sense of isolation that was to colour his remaining years.
Logically this isolation was the natural outcome of lifelong habit. To be free of all obligations was, we have continually noted, Erasmus' chief desire, and that motive, consistently followed, could lead nowhere else than to isolation. Yet here we touch once more upon that other side of his nature which had always been in conflict with the instinct of freedom. In spite of his individuality he needed approval. The breath of adulation was sweet to him. He could be shabby enough to a friend, if he thought himself injured, but that very sensitiveness betrayed his need of friendship. We cannot wonder therefore that henceforth, with increasing age and infirmity, his utterances take on a tone of increasing sadness and sense of loss.