"The substance of what the Romans did," says Sir James Fitz-James Stephen, "was to treat Christianity by fits and starts as a crime."[48] But why a crime? Because the Roman religion, built upon polytheism, was an integral and inseparable part of the Roman State, and whatever menaced the life of the one, threatened the existence of the other. The Romans regarded their religion as "an engine of state which could not be shaken without the utmost danger to their civil government." Cicero further says: "The institutions of the fathers must be defended; it is the part of wisdom to hold fast the sacred rites and ceremonies."[49] Roman statesmen were fully aware of the truthfulness of the statement of a modern writer that, "wherever the religion of any state falls into disregard and contempt it is impossible for that state to subsist long." Now, Christianity was monotheistic, and threatened destruction to polytheism everywhere. And the Romans treated it as a crime because it was regarded as a form of seditious atheism whose teachings and principles were destructive of the established order of things. The Roman conception of the nature of the crime committed by an attack upon the national religion is well illustrated by the following sentence from Döllinger: "If an opinion unfavorable to the apotheosis of any member of the imperial dynasty happened to be dropped, it was dangerous in itself as falling within the purview of the law of high treason; and so it fell out in the case of Thrasea Pætus, who refused to believe in the deification of Poppæa." If it was high treason to refuse to believe in the deification of an emperor or an empress, what other crime could be imputed to him whose design was to destroy an entire religious system, and to pile all the gods and goddesses--Juno and Poppæa, Jupiter and Augustus--in common ruin?