A History of the Papacy from the Great Schism to the Sack of RomeBook I: The Great Schism 1378-1414 (Illustrated) by Mandell Creighton

My aim in this book is to bring together materials for a judgment of the change which came over Europe in the sixteenth century, to which the name of “The Reformation” is loosely given. I have attempted to do this from a strictly historical point of view,— by which I mean that I have contented myself with watching events and noting the gradual development of affairs. I have taken the history of the Papacy as the central point for my investigation, because it gives the largest opportunity for a survey of European affairs as a whole. I have not begun with the actual crisis itself, but have gone back to trace the gradual formation of opinions which were long simmering below the surface before they found actual expression. I purpose, if opportunity should be given me, to continue my survey in succeeding volumes to the dissolution of the Council of Trent.
I have begun with a period of general helplessness, when men felt that the old landmarks were passing away, but did not see what was to take their place. The period of the Great Schism in the Papacy was but a reflection of similar crises in the history of the chief states of Europe. Dreary as the history of the Schism may be, its records show that it gave a great impulse to European thought. The existence of two Papal Courts doubled Papal taxation and produced a deep-seated feeling of the need for some readjustment in the relations of the Papacy towards national churches. The attempts to heal the Schism led to a serious criticism of the Papal system by orthodox theologians, and to an examination of primitive usage which was fruitful for later times. The difficulties experienced in finding any way out of the dilemma called the attention of statesmen to the anomaly of the existence of an irresponsible and indeterminable power. The theological and political basis of the Papacy was discussed, and Europe did not forget the results of the discussion. The power of the State, which at least rested on intelligible grounds, interfered somewhat rudely to heal the breaches of an institution whose pretensions were so lofty that its mechanism, once disordered, could not be amended from within.
The result of many experiments and much discussion was the establishment of a General Council as the ultimate court of appeal. Unsuccessful through its crudity at Pisa, the conciliar system asserted itself at Constance, and was strong enough to answer its immediate purpose, and end the Schism. But when it had done this, it could do nothing more. The abolition of ecclesiastical grievances was beyond its power. Men could not discover the interests of Christendom, because they were overlaid by conflicting interests of classes and nations. The Council, which expressed in the fullest manner the unity of Christendom, showed that that unity was illusory. The conciliar principle was set up as a permanent factor in the organization of the Church, and men hoped that it might be more fortunate in the future.
The condition of Europe and the fortunes of the Papacy offered a brilliant opportunity to the Council of Basel. In some things it succeeded; but it was helpless to reorganize the Church. It attacked, instead of reforming, the Papacy : it proposed to hand over the Church to a self-constituted parliament. The Council of Constance failed because it represented Christendom too faithfully, even to its national dissensions. The Council of Basel failed because, in its endeavor to avoid that danger, it represented nothing save the pretensions of a self-elected, self-seeking body of ecclesiastics...