XLI THE BYZANTINE AND SASSANID EMPIRES

treated as a divinity and the Cæsars were gods in so much as they had altars and temples devoted to them and the offering of incense was made a test of loyalty to the Roman state. But these older religions were essentially religions of act and fact. They did not invade the mind. If a man offered his sacrifice and bowed to the god, he was left not only to think but to say practically whatever he liked about the affair. But the new sort of religions that had come into the world, and particularly Christianity, turned inward. These new faiths demanded not simply conformity but understanding belief. Naturally fierce controversy ensued upon the exact meaning of the things believed. These new religions were creed religions. The world was confronted with a new word, Orthodoxy, and with a stern resolve to keep not only acts but speech and private thought within the limits of a set teaching. For to hold a wrong opinion, much more to convey it to other people, was no longer regarded as an intellectual defect but a moral fault that might condemn a soul to everlasting destruction.