The personal attitude of Diocletian towards religion in general is best seen in the edict which he issued against the Manichæans. The date is somewhat uncertain, but it undoubtedly preceded the anti-Christian edicts. Manichæanism took its rise in Persia, its principal characteristic being the practice of thaumaturgy, and it spread fast throughout the East. Diocletian ordered the chiefs of the sect to be burned to death; their followers were to have their goods confiscated and to suffer capital punishment unless they recanted; while persons of rank who had disgraced themselves by joining such a shameful and infamous set of men were to lose their patrimony and be sent to the mines. These were savage enactments, and it is important to see how the Emperor justified them. Fortunately his language is most explicit. “The gods,” he says, “have determined what is just and true; the wisest of mankind, by counsel and by deed, have proved and firmly established their principles. It is not, therefore, lawful to oppose their divine and human wisdom, or to pretend that a new religion can correct the old one. To wish to change the institutions of our ancestors is the greatest of crimes.” Nothing could be clearer. It is the old official defence of the State religion, that men are not wiser than their fathers, and that innovation in worship is likely to bring down the wrath of the gods. Moreover, as the edict points out, this Manichæanism came from Persia, the traditional enemy of Rome, and threatened to corrupt the “modest and tranquil Roman people” with the detestable manners and infamous laws of the Orient. “Modest and tranquil” are not the epithets which posterity has chosen to apply to the Roman people of the Empire, but Diocletian’s point is obvious. Manichæanism was a device of the enemy; it must be poison, therefore, to the good Roman. Such an argument was born of prejudice rather than of reason; we shall see it applied yet again to the Christians, and applied even by the Christian Church to its own schismatics and heretics.