Jewish ethno-religious history is analyzed as one pole of an interdependent Judeo-Christian system of opposition and symbiosis, in which reciprocal dissociation and projective identification function homeostatically to make history recur and to perpetuate what are ostensibly separate traditions. The nature of identification with the Father and with the Son is explored in the two traditions. Anti-Semitism and anti-Gentilism are seen as mirror images, reflecting what is ego-dystonic and ethosdystonic in Christianity and Judaism. It is argued that the Abraham-Isaac relationship is paradigmatic in Judaism and that throughout Jewish history, the Jewish people have accepted both the sacrificial role of Isaac and the punitive role of Abraham, with the paradoxical consequence that martyrdom is the unconscious symbol of survival.