These Letters of the Council originated in the following way. Three friends in Rome were in the habit of communicating to one another what they heard from persons intimately acquainted with the proceedings of the Council. Belonging as they did to different stations and different classes of life, and having already become familiar, before the opening of the Council, through long residence in Rome, with the state of things and with persons there, and being in free and daily intercourse with some members of the Council, they were very favourably situated for giving a true report as well of the proceedings as of the views of those who took part in it. Their letters were addressed to a friend in Germany, who added now and then historical explanations to elucidate the course of events, and then forwarded them to the _Allgemeine Zeitung_. Much the authors of these Letters could only communicate, because the Bishops themselves, from whose mouth or hand they obtained their materials, were desirous of securing publicity for them in this way, That there should be occasional inaccuracies of detail in matters of subordinate importance was inevitable in drawing up reports which had to be composed as the events occurred, and not seldom had only rumours or conjectures to rest upon. But on the whole we can safely affirm that no substantial error has crept in, and that these reports supply as faithful a portrait as can be given of this Council, so eventful in its bearings on the future history of the Catholic Church, and not only conscientiously exhibit its outward course, but in some degree unveil those more secret and hidden movements whereby the definition of the new dogma of infallibility was brought about. If it were necessary here to adduce testimonies for the truth of these reports, we might appeal to the actual sequence of events, which has so often and so clearly confirmed our predictions and our estimate of the persons concerned and their motives, as well as to the Letters and other works of the Bishops, whether published with or without their names. This collection of Letters then is the best authority for the history of the Vatican Council. No later historian of the Council will be able to dispense with them, and the Liberal Catholic Opposition, whose ecclesiastical conscience protests against the imposition of dogmas effected by all kinds of crooked arts and appliances of force, will find here the most serviceable weapons for combating the legitimacy of the Council.