The pope with whom Innocent is naturally brought into comparison is Hildebrand. They were equally distinguished for moral force, intellectual energy, and proud assertion of prelatic prerogative. Innocent was Hildebrand’s superior in learning, diplomatic tact, and success of administration, but in creative genius and heroic character he was below his predecessor. He stands related to his great predecessor as Augustus to Julius. He was heir to the astounding programme of Hildebrand’s scheme and enjoyed the fruits of his struggles. Their personal fortunes were widely different. Gregory was driven from Rome and died in exile. To Innocent’s good fortune there seemed to be no end, and he closed his pontificate in undisputed possession of authority.
Innocent no sooner ascended the papal chair than he began to give expression to his conception of the papal dignity. Throughout his pontificate he forcibly and clearly expounded it in a tone of mingled official pride and personal humility. At his coronation he preached on the faithful and wise servant. "Ye see," he said, "what manner of servant it is whom the Lord hath set over his people, no other than the viceregent of Christ, the successor of Peter. He stands in the midst between God and man; below God, above man; less than God, more than man. He judges all and is judged by none. But he, whom the pre-eminence of dignity exalts, is humbled by his vocation as a servant, that so humility may be exalted and pride be cast down; for God is against the high-minded, and to the lowly He shows mercy; and whoso exalteth himself shall be abased."
Indeed, the papal theocracy was Innocent’s all-absorbing idea. He was fully convinced that it was established of God for the good of the Church and the salvation of the world. As God gave to Christ all power in heaven and on earth, so Christ delegated to Peter and his successors the same authority. Not man but God founded the Apostolic see.181 In his famous letter to the patriarch of Constantinople, Nov. 12, 1199,182 he gave an elaborate exposition of the commission to Peter. To him alone the command had been given, "Feed my sheep." On him alone it had been declared, "I will build my church." The pope is the vicar of Christ, yea of God himself.183 Not only is he intrusted with the dominion of the Church, but also with the rule of the whole world. Like Melchizedek, he is at once king and priest. All things in heaven and earth and in hell are subject to Christ. So are they also to his vicar. He can depose princes and absolve subjects from the oath of allegiance. He may enforce submission by placing whole nations under the interdict. Peter alone went to Jesus on the water and by so doing he gave illustration of the unique privilege of the papacy to govern the whole earth. For the other disciples stayed in the ship and so to them was given rule only over single provinces. And as the waters were many on which Peter walked, so over the many congregations and nations, which the waters represent, was Peter given authority—yea over all nations whatsoever (universos populos).184 In this letter he also clearly teaches papal infallibility and declares that Peter’s successor can never in any way depart from the Catholic faith.
Gregory VII.’s illustration, likening the priestly estate (sacerdotium) to the sun, and the civil estate (regnum or imperium) to the moon, Innocent amplified and emphasized. Two great lights, Innocent said, were placed by God in the firmament of heaven, and to these correspond the "pontifical authority and the regal authority," the one to rule over souls as the sun rules over the day, the other to rule over the bodies of men as the moon rules over the night. And as the moon gets its light from the sun, and as it is also less than the sun both in quality and in size, and in the effect produced, so the regal power gets its dignity and splendor from the pontifical authority which has in it more inherent virtue.185 The priest anoints the king, not the king the priest, and superior is he that anoints to the anointed.186 Princes have authority in separate lands; the pontiff over all lands. The priesthood came by divine creation; the kingly power by man’s manipulation and violence.187 "As in the ark of God," so he wrote to John of England, "the rod and the manna lay beside the tables of the law, so at the side of the knowledge of the law, in the breast of the pope, are lodged the terrible power of destruction and the genial mildness of grace." Innocent reminded John that if he did not lift his foot from off the Church, nothing would check his punishment and fall.188 Monarchs throughout Europe listened to Innocent’s exposition and obeyed. His correspondence abounds with letters to the emperor, the kings of Hungary, Bohemia, Sicily, France, England, the Danes, Aragon, and to other princes, teaching them their duty and demanding their submission.
Under Innocent’s rule, the subjection of the entire Christian world to the Roman pontiff seemed to be near realization. But the measures of force which were employed in the Latin conquest of Constantinople, 1204, had the opposite effect from what was intended. The overthrow of the Byzantine empire and the establishment of a Latin empire in its stead and the creation of a new hierarchy of Constantinople only completed the final alienation of the Greek and Latin churches. To Innocent III. may not be denied deep concern in the extension of Christendom. But the rigorous system of the Inquisition which he set on foot begat bitterness and war of churchman against Christian dissenter and of Christian against Mohammedan. More blood was shed at the hand of the Church during the pontificate of Innocent, and under his immediate successors carrying out his policy, than in any other age except during the papal counter-Reformation in the sixteenth and seventeenth centuries. The audacious papal claim to imperialism corrected itself by the policy employed by Innocent and his successors to establish the claim over the souls and bodies of men and the governments of the earth.189