In modern times, various Jewish groups have argued whether Jewishness is a function of ethnicity, of nationality, of religion, or of all three. These fundamental conceptions were already in place in antiquity. The peculiar combination of ethnicity, nationality, and religion that would characterize Jewishness through the centuries first took shape in the second century B.C.E. This brilliantly argued, accessible book unravels one of the most complex issues of late antiquity by showing how these elements were understood and applied in the construction of Jewish identity--by Jews, by gentiles,...