During this third period then the Church, more and more confined in practice to the West, had in spite of the political chaos and the consequent moral decadence, maintained its unity, and the papacy, in spite of its dependence, had maintained its author ity. Once this papal power fell into the hands of a man of genius it was capable of leading Europe, and of re-establishing the old traditions of civilisation.
D. The Fourth Period.—This is the most important of our periods, for during it the status of the Church as a society is definitely established. Protestantism did not affect the Catholic doctrine on the constitution of the Church ; this owed nothing of its development to the attacks of the Reformers. The chief modern development, the definition of papal infallibility, was an answer rather to mediaeval errors.
St. Leo showed at once that he was not content with imperial nomination; he therefore insisted on election. But apart from this his pontificate and that of Victor II. were spent mainly in promoting definitely clerical reforms. By Victor's death there was at Rome a strong party of zealous reformers under the leader ship of Hildebrand. Further, the movement towards reform directed by Rome had spread throughout Europe; allies had been found who though helpful would not be domineering; the Roman nobles had been suppressed, and papal temporal authority in Rome restored ; finally papal finances had been reorganised. All this was mainly the work of Hildebrand. The Eastern Church also had at last broken from communion with Rome. This lamentable defection still further confirmed the identification of the Latin patriarchate with the Church, which so encouraged the formation of the Christian kingdom.
During the reign of Stephen IX. (X.) attention was expressly directed to the evil of lay control over Churchmen. In this con trol Cardinal Humbert in his book against simony found the main source of the prevalent evils. The minority of the new German king, Henry IV., and the consequent intrigues taught the same lesson. The systematic government of the Church would tend to keep the reform active, providing bad appointments did not take place. But such appointments would certainly be made if lay control continued since there could be no guarantee against bad or weak lay rulers.
The work already accomplished had started the necessary re forms within the Church. But these, especially clerical celibacy and the suppression of simony, were being bitterly resisted. As
the young Henry grew older he chose the worst advisers, and fostered the evils that Hildebrand and his friends were deter mined to destroy. In 1073 Hildebrand himself was forced to become pope. He chose the title Gregory VII. After warning Henry he solemnly excommunicated him. This act, unprecedented for centuries, startled Europe. That the emperor designate, the temporal ruler of the Christian kingdom, should be expelled from that kingdom, forced men to ask which was the true authority over the Church. This was the issue at stake; the investiture difficulty was merely a practical presentation of the problem. In addition to the power of ruling a ruler must have jurisdiction, i.e., must have subjects assigned to him. Though nobody thought that a lay ruler could ordain or consecrate, the practice of lay investi ture suggested that he was the source of jurisdiction. Thus this practice gave lay rulers practically the right to appoint spiritual authorities, and this rendered numerous bad appointments in evitable. To combat this evil, which led to so many others, St. Gregory condemned lay investiture, and when Henry persisted in it excommunicated him. The struggle continued with varying fortunes till 1122 when by the Concordat of Worms the papacy under Calixtus II. secured the victory.
This Concordat is usually called a compromise. On the question of investiture itself it is indeed a compromise, but on the wider issues at stake the struggle had ended in a papal victory. The object of the Hildebrandine movement had been the reform of European society through the reform of clerical life. This end was reached : we have but to compare the Europe of Benedict IX. with that of St. Bernard to see this. Abuses indeed remained; as long as men are men the cockle will grow with the wheat. But the general tone of Europe was incomparably higher. Again though in the concordat the papacy had modified some extreme claims, it had lost no right that it had actually possessed; but the emperor had lost much. The papacy was free ; never again did an em peror successfully make and unmake popes as Henry III. had done. Though also the popes recognized the emperor's right to homage from clerics and allowed him therefore a supervision of elections even in Germany this was merely a supervision.