The general rule of Roman policy was to tolerate throughout the Empire all religions and all opinions.  Blasphemy was not punished.  The principle was expressed in the maxim of the Emperor Tiberius:  “If the gods are insulted, let them see to it themselves.”  An exception to the rule of tolerance

[41] was made in the case of the Christian sect, and the treatment of this Oriental religion may be said to have inaugurated religious persecution in Europe.  It is a matter of interest to understand why Emperors who were able, humane, and not in the least fanatical, adopted this exceptional policy.

For a long time the Christians were only known to those Romans who happened to hear of them, as a sect of the Jews.  The Jewish was the one religion which, on account of its exclusiveness and intolerance, was regarded by the tolerant pagans with disfavour and suspicion.  But though it sometimes came into collision with the Roman authorities and some ill-advised attacks upon it were made, it was the constant policy of the Emperors to let it alone and to protect the Jews against the hatred which their own fanaticism aroused.  But while the Jewish religion was endured so long as it was confined to those who were born into it, the prospect of its dissemination raised a new question.  Grave misgivings might arise in the mind of a ruler at seeing a creed spreading which was aggressively hostile to all the other creeds of the world—­creeds which lived together in amity—­and had earned for its adherents the reputation of being the enemies of the human race.  Might not its expansion

[42] beyond the Israelites involve ultimately a danger to the Empire?  For its spirit was incompatible with the traditions and basis of Roman society.  The Emperor Domitian seems to have seen the question in this light, and he took severe measures to hinder the proselytizing of Roman citizens.  Some of those whom he struck may have been Christians, but if he was aware of the distinction, there was from his point of view no difference.  Christianity resembled Judaism, from which it sprang, in intolerance and in hostility towards Roman society, but it differed by the fact that it made many proselytes while Judaism made few.

Under Trajan we find that the principle has been laid down that to be a Christian is an offence punishable by death.  Henceforward Christianity remained an illegal religion.  But in practice the law was not applied rigorously or logically.  The Emperors desired, if possible, to extirpate Christianity without shedding blood.  Trajan laid down that Christians were not to be sought out, that no anonymous charges were to be noticed, and that an informer who failed to make good his charge should be liable to be punished under the laws against calumny.  Christians themselves recognized that this edict practically protected them.  There were