Luther showed the defects of a “genius” not least in his vituperation and in the other far from commendable methods he used in his polemics. It was precisely these defects which led Erasmus to question whether he was quite in his right mind. “Had a man said this in the delirium of fever, could he have uttered anything more insane?” Thus Erasmus in his “Hyperaspistes.”[545] He often speaks of his opponent’s feverish fancies. He denies that his spirit is a “sober” one, and maliciously supposes that he was drunk. In spite of his usual moderation and reticence, the scholar, when dealing with Luther’s assertions, constantly uses such words as “_delirus_,” “_insanus_,” “_lymphatus_,” “_sine mente_,” “_mera insania_.” On one occasion he says of the “devils, spectres, ‘_lamiæ_,’ ‘_megæræ_’ and other more than tragic words” which Luther was addicted to flinging at his foes, that such a habit was a “sign of coming madness” (“_venturæ insaniæ præsagia_”); elsewhere he views with misgiving the sort of compulsion (“_non agere sed agi_”) which urges Luther to abuse all who differ from him.[546] In other circles, too, the opinion prevailed that Luther was suffering from some sort of mental disease. We may recall the remarks of Boniface Amerbach, who was not unkindly disposed to Luther, in sending the latter’s tract of 1534 against Erasmus, to his brother Basil (above, vol. iv., p. 183). In Luther’s immediate surroundings we also find traces of a fear that the Master stood in some danger of losing his mind. A thoroughgoing investigation of the matter by some unbiassed expert in mental diseases would, however, be of immeasurably greater value than the mere opinions of contemporary admirers and opponents. But the difficulty is to find an impartial expert. Protestant theologians will not easily be found ready to agree with Catholic writers regarding the process which made of a quondam monk the founder of the Protestant faith, or to see Luther’s scruples in quite the same light. Entire agreement would seem for ever excluded, owing to differences of outlook so deep-seated. If, to some, Luther appears as a “new Paul,” and as one who removed every obstacle to free religious research, then the view they take of his inward change and later spiritual life must perforce be coloured to some extent by this idea.