It was concrete religion, in its unity and catholicity embodied in the church as an institution, that was able during the middle ages to assert the freedom and independence of the spiritual order, which is only another term for the freedom and independence of conscience, against the political order. She was thus constituted a living reality, a concrete power, and the powers of the earth had to reckon with her. Constituted as society then was, she needed and exercised more positive power in the temporal order than was agreeable to her, or than is necessary in a society constituted like ours. The republic, then, was pagan, and sought to be supreme everywhere and in everything, or in other words, to subject the spiritual order to the temporal, as it was in pagan Rome, and for the most part continued to be even in Christian Rome of the East, till its conquest by the Turks. Hence the relation between Peter and Cesar, between the pope and emperor, was ordinarily that of antagonism. {12} It was necessary that the pope should be clothed with a power that could control princes, and force them to respect the rights of conscience, or the independence of the church, which to be sufficient must be positive as well as negative. The temporal authority, or the authority of the church over the temporal, claimed and exercised over secular princes seeking to combine in themselves both the imperial and the pontifical power, was no usurpation, and rested on no grant of civil society, or _jus publicum_, as has sometimes been asserted, but grew out of the necessity of the case; its justification was in its necessity to maintain her own independence in spirituals, or the freedom of conscience. It was her right as representing the spiritual order, and would be her right still in a similarly constituted society, and the modern world is reaping in its advanced civilization the fruits of her having claimed and exercised it.