Nothing can equal the enormity of the tributes that were imposed upon the clergy for carrying on the holy wars. The tenths were not only levied for the crusades, but for every attempt at a crusade; not only for expeditions to the East, but for every enterprise against the enemies of the court of Rome. They were at length levied under the most vain pretexts; all Europe addressed warm remonstrances to the popes; at first the rigour with which the agents collected the tributes was complained of; and afterwards their infidelity in the application of the treasures extorted from the faithful became equally a subject of scandal. Nothing could be more injurious to the pontifical authority than these complaints, which arose from all quarters, and which, in the end, furnished weapons for the formidable heresy of Luther. The history of the popes in the middle ages completes the proof of that which we have said. Their domination went on constantly increasing during a century up to Innocent III.; it after that period declined during another century, down to Boniface VIII., at which time crusades beyond the seas ended. In latter days, publicists have said a great deal about the power of the heads of the Church; but they have judged rather according to systems than according to facts,—more after the spirit of our own age than that of the middle ages. The genius of the sovereign pontiffs has been much lauded, particularly for the purpose of placing their ambition in a stronger light. But if the popes really had the genius and the ambition attributed to them, we must believe they would have been principally employed in aggrandizing their states, and increasing their authority as sovereigns. Nevertheless, they did not succeed in this, or else they never attempted it. In fact, what could men do, who were mostly arrived at the age of decrepitude?—what could princes do, who merely passed over the throne, to strengthen their authority, and master the passions belonging to the infancy and the youth of societies? Among the crowd of popes who succeeded each other, many were endowed with a superior genius, whilst others only possessed a moderate capacity; men of all characters and all turns of mind occupied, in succession, the chair of St. Peter; nevertheless, these men, so different by their tastes, their passions, and their talents, all aimed at and all did the same thing; they had, therefore, an impulsion which was not in themselves, the motive of which must be sought elsewhere than in the vulgar policy of princes.