With the best of intentions Planck spent part of his time and strength in the chimerical task of bringing about a “reunion of the principal Christian bodies.” He wrote a work, “Ueber die Trennung und Wiedervereinigung,” etc. (on Schism and Reunion, 1803), and another entitled “Worte des Friedens an die katholische Kirche” (Words of Peace to the Catholic Church, 1809). It was his desire “to seek out the good which surely exists everywhere.” The ideas he put forward were, it is true, unsuited for the realisation of his great plan. He was too unfamiliar with the organisation of the Catholic Church, and the limitations of his earlier education disqualified him for the undertaking he had in view. What really shattered the hopes of reunion held by many during that period of triumphant Rationalism was, not merely the shallowness of the views prevailing, but above all the spirit of animosity let loose among all fervent Lutherans by the celebration, in 1817, of the third centenary of the Reformation. Catholics soon perceived that reunion was unfortunately still very far distant, and that, in the interests of the public peace, all that could be expected was the retention of mutual esteem and Christian charity between the two great denominations. It is also my most ardent desire that esteem and charity should increase, and this growth of appreciation between Catholics and Protestants will certainly not be hindered by the free and untrammelled discussion of matters of history. On the contrary, as a Protestant critic of Walter Köhler’s “Katholizismus und Reformation” says, “it is to be hoped that historical investigation may lessen the contradictions, and if in this way it is possible to come closer together, not indeed perhaps to understand each other completely, yet at least to make some attempt to do so, then something deeper and more lasting will have been gained than at the time when Rationalism prevailed. The attempt then made to bring the parties together was the result of a levelling down of religious beliefs, now the same object is sought by penetrating more profoundly into the essentials of the different creeds” (“Theologische Literaturzeitung,” 1907, p. 250). The quotations from Luther’s writings have been taken from the most recent Weimar edition so far as it at present reaches. What is not contained in the Weimar edition has been taken from the previous Erlangen edition (method of quotation: Weim. ed., Erl. ed.); the latter is, however, often quoted as well as the Weimar edition because it is more widely known and more readily available for reference.