dedicated to the “people of God,” the mosaics in Santa Maria Maggiore, at Rome; and beneath the sacred persons whom he had caused to be pourtrayed, he placed the following inscription: “Xistus episcopus plebi Dei.”* Thus, at the two extreme points of the middle ages, viz. the fifth and sixteenth centuries, the same idea prevailed, and even found expression in the same words. Between those two limits it was propounded in detail, and often commented upon with eloquence. So, at the close of the seventh