[Sidenote: Duties attributed to the Empire by the developed theory.]
To that position three cardinal duties were attached. He who held it must typify spiritual unity, must preserve peace, must be a fountain of that by which alone among imperfect men peace is preserved and restored, law and justice. The first of these three objects was sought not only on religious grounds, but also from that longing for a wider brotherhood of humanity towards which, ever since the barrier between Jew and Gentile, Greek and barbarian, was broken down, the aspirations of the higher minds of the world have been constantly directed. Placed in the midst of Europe, the Emperor was to bind its tribes into one body, reminding them of their common faith, their common blood, their common interest in each other's welfare. And he was therefore above all things, professing indeed to be upon earth the representative of the Prince of Peace, bound to listen to complaints, and to redress the injuries inflicted by sovereigns or people upon each other; to punish offenders against the public order of Christendom; to maintain through the world, looking down as from a serene height upon the schemes and quarrels of meaner potentates, that supreme good without which neither arts nor letters, nor the gentler virtues of life, can rise and flourish. The mediæval Empire was in its essence what the modern despotisms that mimic it profess themselves: the Empire was peace[279]: the oldest and noblest title of its head was 'Imperator pacificus[280].' And that he might be the peacemaker, he must be the expounder of justice and the author of its concrete embodiment, positive law; chief legislator and supreme judge of appeal, like his predecessor the compiler of the Corpus Iuris, the one and only source of all legitimate authority. In this sense, as governor and administrator, not as owner, is he, in the words of the jurists, Lord of the world; not that its soil belongs to him in the same sense in which the soil of France or England belongs to their respective kings: he is the steward of Him who has received the heathen for his possession and the uttermost parts of the earth for his inheritance. It is, therefore, by him alone that the idea of pure right, acquired not by force but by legitimate devolution from those whom God himself had set up, is visibly expressed upon earth. To find an external and positive basis for that idea is a problem which it has at all times been more easy to evade than to solve, and one peculiarly distressing to those who could neither explain the phenomena of society by reducing it to its original principles, nor inquire historically how its existing arrangements had grown up. Hence the attempt to represent human government as an emanation from divine: a view from which all the similar but far less logically consistent doctrines of divine right which have prevailed in later times are borrowed. As has been said already, there is not a trace of the notion that the Emperor reigns by an hereditary right of his own or by the will of the people, for such a theory would have seemed to the men of the middle ages an absurd and wicked perversion of the true order. Nor do his powers come to him from those who choose him, but from God, who uses the electoral princes as mere instruments of nomination. Having such an origin, his rights exist irrespective of their actual exercise, and no voluntary abandonment, not even an express grant, can impair them. Boniface the Eighth[281] reminds the king of France, and imperialist lawyers till the seventeenth century repeated the claim, that he, like other princes, is of right and must ever remain subject to the Roman Emperor. And the sovereigns of Europe long continued to address the Emperor in language, and yield to him a precedence, which admitted the inferiority of their own position[282].