Many Byzantines were certain that cures could be effected by touching the arms, legs, and even the congealed sweat of some holy man. On the other hand, a doctor was howled down by the mob when he suggested ending a plague by letting fresh air into the crowded tenements. “Blasphemy!” cried the Byzantines. “God decides when a man shall die, not fresh air!” When the doctor persisted, and died himself, they said God had punished him. Others believed that cities had been saved by the apparition of some saint as much as by soldiers. For instance, when the Goths stormed toward Thessalonica (modern Salonika), the second city of the empire, Saint Demetrius appeared and led the East Roman army to victory. When the Avars reached Constantinople, the khagan saw a majestic female figure pacing the walls. It was the Theotokos, the Greek word for “Mother of God,” which the Byzantines called the Virgin Mary. He turned back in panic. Almost all the Byzantines paid great attention to fortunetelling, palm reading, and prophecies. Everybody believed in them. There were even more than a few emperors of humble birth who would not have even dared to try seizing the throne if it had not been for a fortuneteller or a prophecy. But, although sometimes the monks and abbots themselves told some of these fortunes, none of this had much to do with the church. The Byzantine, even the most superstitious Byzantine, was truly Christian, but that did not mean he tolerated every kind of Christianity in existence. The Byzantine did not believe, as most of us do, that religion is a personal matter and that every man has a right to worship God in his own way, according to his own conscience. To the Byzantine, there was only one religion—the official religion. And there was only one church—his own Orthodox Church. If you believed anything else, you were a heretic and to be persecuted or fought. This had been so from the very beginning. Constantine himself had called council after council to work out the details of the Christian creed, and the emperors who followed carried on his work. In council after council, they wrote down in black and white what every Byzantine had to believe. When it was written down, that was _it_. No further discussion about it, unless you enjoyed exile or having insulting poetry branded on your forehead; and this last really happened to one poor monk who refused to conform. It was still true in the last days of the empire, but by then not even the emperor could change what had been agreed on earlier. Some of the later emperors tried to. They journeyed to France, Italy, and even England seeking help against the Turks, and in order to get the Western nations on their side they promised to make the Orthodox Church join the Roman Catholic Church, with the Pope as head of both.