A Concept That Justified Bringing in New Gods

Because pax deorum was understood as the practical measure of Rome's religious health, the concept could justify remarkably flexible action when existing cult seemed insufficient to restore it, most famously the Senate's decision in 205 BCE, during the darkest years of the war against Hannibal, to import the cult of the Anatolian goddess Cybele, the Magna Mater, directly from Pessinus to Rome on the advice of the Sibylline Books, a foreign and, in some respects, culturally unsettling cult welcomed into the city precisely because restoring the peace of the gods was judged more urgent than any discomfort at its foreignness. The same logic underlay the practice of evocatio, formally inviting an enemy city's own tutelary deity to relocate to Rome before or during a siege, since a hostile god left in place with its city might itself represent a threat to Rome's religious security, whereas a persuaded and properly received god became part of Rome's own expanding pantheon and, by extension, part of what its pax deorum now had to maintain. Historians of Roman religion read this consistent willingness to add new cult, rather than defend a fixed traditional roster, as one of the clearest structural features distinguishing Roman religious practice from a modern expectation of doctrinal or theological consistency.