Luther mistook the genius of Christianity in introducing a new principle into the world--the immediate authority of the Bible as the sole criterion of the truth. If tradition is to be rejected, it follows that the Bible cannot be authoritatively explained by acquired knowledge; in a word, human interpretation based upon its comprehensions of the Greek and Hebrew languages. So, by this theory, the palladium of orthodoxy is to be found in a knowledge of foreign tongues, and living authority is replaced by a dead letter; a slavery a thousand times more oppressive than the yoke of tradition. Has any dogmatist succeeded in drawing up a confession of faith by means of the Bible which could not be attacked by means of reason? This formula, that the Bible must be the "_unicum principium theologiae_," is the source of contradictory doctrines in Protestant theology; hence this question arises: "What Protestant theology is there in which there are not errors more or less?" It was the Bible that inspired all the neologists of the sixteenth century; the Bible that they made use of to persecute and condemn themselves as heretics. When Luther maintained that the Bible contains the enunciation of all the truths of which a knowledge is necessary to salvation, and that no doctrine which is not distinctly laid down in the Bible can be regarded as an article of faith, he did not imagine that the time was at hand when everybody, from this very volume, would form a confession for himself, and reject all others which contradicted his individual creed. This necessity for inquiry so occupies the minds of men at the present day that the principal articles of the original creed are rejected by those who call themselves the disciples of Jesus. But what are we to understand by the Bible? The question was a difficult one to solve even at the beginning of the Reformation, when Luther, in his preface to the translation of the Bible, laid down a difference between the canonical books by preferring the gospel of St. John to the three other evangelists; by depreciating the Epistle of St. James as an epistle of straw, that contained nothing of the Gospel in it, and which an apostle could not have written, since it attributes to works a merit which they did not possess. It was in the Bible that Luther discovered these two great truths of salvation, which he revealed to the world at the beginning of his apostleship--_the slavery of man's will, and the impeccability of the believer_.