It was the sublime effort of Leo to make the Church the guardian of spiritual principles and give to it a theocratic character and aim, which links his name with the mightiest moral movements of the world; and when I speak of the Church I mean the Church of Rome, as presided over by men who claimed to be the successors of Saint Peter,--to whom they assert Christ had given the supreme control over all other churches as His vicars on the earth. It was the great object of Leo to substantiate this claim, and root it in the minds of the newly converted barbarians; and then institute laws and measures which should make his authority and that of his successors paramount in all spiritual matters, thus centring in his See the general oversight of the Christian Church in all the countries of Europe. It was a theocratic aspiration, one of the grandest that ever entered into the mind of a man of genius, yet, as Protestants now look at it, a usurpation,--the beginning of a vast system of spiritual tyranny in order to control the minds and consciences of men. It took several centuries to develop this system, after Leo was dead. With him it was not a vulgar greed of power, but an inspiration of genius,--a grand idea to make the Church which he controlled a benign and potent influence on society, and to prevent civilization from being utterly crushed out by the victorious Goths and Vandals. It is the success of this idea which stamps the Church as the great leading power of Mediaeval Ages,--a power alike majestic and venerable, benignant yet despotic, humble yet arrogant and usurping. But before I can present this subtile contradiction, in all its mighty consequences both for good and evil, I must allude to the Roman See and the condition of society when Leo began his memorable pontificate as the precursor of the Gregories and the Clements of later times. Like all great powers, it was very gradually developed. It was as long in reaching its culminating greatness as that temporal empire which controlled the ancient world. Pagan Rome extended her sway by generals and armies; Mediaeval Rome, by her prelates and her principles.