At the same time that this political movement was going on in the State, a religious and intellectual ferment was making head in the Church and in men's minds.

After the conquest of the Gauls by the Franks, the Christian clergy, sole depositaries of all lights to lighten their age, and sole possessors of any idea of opposing the conquerors with arguments other than those of brute force, or of employing towards the vanquished any instrument of subjection other than violence, became the connecting link between the nation of the conquerors and the nation of the conquered, and, in the name of one and the same divine law, enjoined obedience on the subjects, and, in the case of the masters, moderated the transports of power.

But in the course of this active and salutary participation in the affairs of the world, the Christian clergy lost somewhat of their primitive and proper character; religion in their hands was a means of power as well as of civilization; and its principal members became rich, and frequently substituted material weapons for the spiritual authority which had originally been their only reliance.

When they were in a condition to hold their own against powerful laymen, they frequently adopted the powerful laymen's morals and shared their ignorance; and in the seventh and eighth centuries the barbarism which held the world in its clutches had made inroads upon the Church.
Charlemagne essayed to resuscitate dying civilization, and sought amongst the clergy his chief means of success; he founded schools, filled them with students to whom promises of ecclesiastical preferments were held out as rewards of their merit, and, in fine, exerted himself with all his might to restore to the Christian Church her dignity and her influence.
When Charlemagne was dead, nearly all his great achievements disappeared in the chaos which came after him; his schools alone survived and preserved certain centres of intellectual activity.

When the feudal system had become established, and had introduced some rule into social relations, when the fate of mankind appeared no longer entirely left to the risks of force, intellect once more found some sort of employment, and once more assumed some sort of sway.