This book explores where anti-Jewish racism first appeared and why. Abel shows how certain such feelings arose with Egypt during the Ptolemaic kingdom, as Jews attempted to differentiate themselves from Egyptians and often took on unsavory leadership roles such as tax collecting. This did not endear them to the Egyptians.
The attitude among the Greeks and Romans, however, was more complex. Jews were sometimes respected for their "philosophical" religion, which presented a moral world unlike that in the Greco-Roman culture. At the same time, the Jewish refusal to honor the gods, outside of their own, set them apart and disgusted their neighbors insofar as such views made the Jews seem to be self-righteous. Despite various uprisings that occurred throughout the history of the Roman Empire, the Jews were largely allowed to maintain their religion and were not looked down upon, though other peoples sometimes were annoyed by the exceptions made for the Jews, a view that was extended by the special tax eventually levied on the Jews after one of their revolts. This tax was not heavy, but it further set the Jews apart. That said, the luxuries extended to the Jews were not extended so much to converts to Judaism, a practice Rome did its best to quell, given the way that Jews didn't take full part in Roman society.
The real start of anti-Judaism feeling began with Christianity, which attempted to set itself apart from Judaism, both to avoid religious persecution from the Jews and social persecution by the Romans. When Christianity took the helm as the favored religion of Rome, its anti-Jewishness spread throughout society in a way that continues to reverberate even today.