" The notion that the Jew knew the truth but rejected it, preferring to work with the forces of darkness–and therefore could not be human in the sense that Christians were–was already well established. The Jew’s unnatural and inhuman relations with the Judensau drove it ever more firmly into the German popular mind. And if a particular category of person was not human, it could effectively be excluded from society. That, indeed, was what was already happening. For the walls of hatred, far from disappearing, were being replaced by real ones, as the European ghetto made its appearance. "

― Paul Johnson , A History of the Jews