Public health, argues Gary Ferngren ( Medicine and Health Care in Early Christianity ), was a Christian invention: “Except for making supplications to the gods, [ancient Greco-Roman] civil authorities did little to alleviate the situation [during plagues].  Responsibility for health was regarded as a private, not a public concern.”

More elaborately: “In the classical world there was little recognition of social responsibilities on the part of the individual.  Before the advent of Christianity, moreover, there was no concept of the responsibility of public officials to prevent disease or to treat those who suffered from it.  Alex Scobie speaks of ‘a cynical acceptance of the state’s indifference to the lot of the urban poor.’  In part, this can be explained by the belief in pollution ( miasma ) and purification ( katharsis ).  The general acceptance of calamities as the retribution of the gods that indicated their displeasure was deeply rooted in Greek and Roman religion and remained a part of paganism until the end of antiquity.  Plague was attributed to the gods, who punishment men for having violated a taboo or incurred divine displeasure by bringing pollution on a city, whether intentionally or unintentionally - but not for moral offenses, since the gods imposed no ethical requirements.  Only public sacrifice or purification could satisfy the anger of the gods.”  On the other hand “Christian belief in personal and corporate philanthropy as an outworking of Christian concepts of agape and the inherent worth of individuals who bore God’s image . . . introduced into the classical world the concept of social responsibility in treating epidemic disease.”

Just as fundamentally, it seems, Christianity promoted public health by announcing that Christ’s death had brought an end to systems of pollution and purification.