He found in clear outline in the Greek philosophy, the theory of merely human society; and raising its end and purpose, "_finem totius humanæ civilitatis_," to a height and dignity which Heathens could not forecast, he adopted it in its more abstract and ideal form. He imagined a single authority, unselfish, inflexible, irresistible, which could make all smaller tyrannies to cease, and enable every man to live in peace and liberty, so that he lived in justice. It is simply what each separate state of Christendom has by this time more or less perfectly achieved. The theoriser of the middle ages could conceive of its accomplishment only in one form, as grand as it was impossible--a universal monarchy. But he did not start from an abstraction. He believed that history attested the existence of such a monarchy. The prestige of the Roman empire was then strong. Europe still lingers on the idea, and cannot even yet bring itself to give up its part in that great monument of human power. But in the middle ages the Empire was still believed to exist. It was the last greatness which had been seen in the world, and the world would not believe that it was over. Above all, in Italy, a continuity of lineage, of language, of local names, and in part of civilisation and law, forbad the thought that the great Roman people had ceased to be. Florentines and Venetians boasted that they were Romans: the legends which the Florentine ladies told to their maidens at the loom were tales of their mother city, Rome. The Roman element, little understood, but profoundly reverenced and dearly cherished, was dominant; the conductor of civilisation, and enfolding the inheritance of all the wisdom, experience, feeling, art, of the past, it elevated, even while it overawed, oppressed, and enslaved. A deep belief in Providence added to the intrinsic grandeur of the empire a sacred character. The flight of the eagle has been often told and often sung; but neither in Livy or Virgil, Gibbon or Bossuet, with intenser sympathy or more kindred power, than in those rushing and unflagging verses in which the middle-age poet hears the imperial legislator relate the fated course of the "sacred sign," from the day when Pallas died for it, till it accomplished the vengeance of heaven in Judæa, and afterwards, under Charlemagne, smote down the enemies of the Church.[82] [Footnote 82: _Parad._ c. 6.] The following passage, from the _De Monarchia_, will show the poet's view of the Roman empire, and its office in the world: