More than any other human institution the Papacy has suffered from a supposed necessity of justifying every forward step by precedent and reference to authority. Twice in the course of sixteen centuries the Holy See has ventured on a startling change of front, and has been sorely embarrassed to rebut the charge of inconsistency. One such change was silently effected at the close of the seventeenth century, when the Popes ceased to concern themselves more than was unavoidable with international affairs. This was a great change; yet not so great as that made in the latter part of the eleventh century, by Gregory VII. For he revolutionised the whole theory of papal prerogative. Neither a profound lawyer nor a profound theologian, he regarded the past history of his office with the idealism of a poet, and looked into its future with the sanguine radicalism of a Machiavelli or a Hobbes. Gregory VII conceived of Christendom as an undivided state; of a state as a polity dominated by a sovereign; of a sovereign as a ruler who must be either absolute or useless. And who, he asked, but the heir of the Prince of the Apostles could presume to claim a power so tremendous? For us the audacity of his pretensions is excused by the lofty aims which they were meant to serve. To conciliate contemporary opinion it was necessary that the new claims should be represented as the revival of old rights, as the logical corollaries of undisputed truths. And this course involved as its consequence an industrious, if partially unconscious, perversion of past history. For the Popes who had gone before him claimed powers which, though extensive, were capable of definition; which, though startling, could in the main be defended by appeal to well-established usage. The new policy led to this paradoxical situation, that precedents were diligently invoked to prove the Pope superior to all precedents. With Gregory VII the primacy of Western Christendom assumed a new character. But the primacy, in one form or another, had for centuries belonged to the Roman See. So much his remote predecessors had achieved, and their success is all the more remarkable when we remember how few of them had been distinguished statesmen. It is no matter for surprise that, in the course of nine troubled centuries, some Bishops of Borne had proved incompetent and others had betrayed the interests committed to their charge. It is, however, surprising that the Roman See was able to assume and hold the leading position among Western bishops without rendering much service to the extension or the organisation of the Church.