Near the end of Augustine and the Jews, her brilliant and challenging new book, Paula Fredriksen offers a summary of the remarks about Jews that Saint Augustine made in his sermons on the Gospel of John. This Gospel is by far the most hostile of the four in its depiction of the Jews of Jesus’ time—”You are of your father the devil,” John’s Jesus tells his fellow Jews—making it what Fredriksen calls “the bane of modern interfaith dialogue.” And it provoked an equivalent harshness in the great Christian philosopher. Of the 124 sermons in the series, Fredriksen writes, 60 “contain appreciable anti-Jewish material, and between fifteen and seventeen are extensively or completely taken up with it.” “When he is not itemizing Jewish sinfulness (‘malice,’ ‘evil,’ ‘perversity,’ ‘hatefulness’),” she goes on, Augustine “laments Jewish spite, envy, and arrogance.” He blames the Jews, past, present, and future, for the death of Christ; he disparages the sacrifices of the ancient Israelites as God’s concession to the pagan tendencies of a “fleshly,” “stony-hearted” people; he mocks Jewish observance of Shabbat (“God forbid.that we call that kind of thing ‘observing the Sabbath.'”) “Is the living temple of God to be laid low by your blows?” Augustine demands, rhetorically, of the Jews; “Have you become so hardened, false Israelites?”After all this, it would be easy to regard the subtitle of Fredriksen’s book as a bitter joke; for Augustine’s theology, she insists, constitutes “A Christian Defense of Jews and Judaism.” With defenders like these, the Jewish reader might feel, who needs attackers? Yet there can be no doubt of Fredriksen’s passionate sincerity, or of the ingenuity with which she tries to interpret Augustine’s thought as, in some sense, respectful of Judaism. Modern, liberal, secular eyes may find it hard to detect much daylight between Augustine’s Johannine sermons and the virulent tracts of, say, Tertullian, the Church Father and master calumniator of the Jews. To Fredriksen, who reveres Augustine as one of the subtlest and most profound Christian thinkers, it is morally imperative to stress that there is a difference. “In the changed social context of medieval Christendom,” she concludes, Augustine’s thought “ultimately would safeguard Jewish lives,” serving as a bulwark against the Crusaders who wanted to wipe the Jews off the face of the earth.Augustine may have had no love for Jews or Judaism, but he nevertheless believed that God’s plan required their preservation. His favorite text on the subject was Psalms 59:12, in which the Psalmist implores God, “Do not kill them lest my people be unmindful; with Your power make wanderers of them.” This is just one of countless instances in the Psalms where the poet calls down God’s vengeance on Israel’s enemies. But to Augustine, a master of typological reading, the verse was actually a prophecy of what would befall Israel itself after the crucifixion. God would not kill the Jews as punishment for their treacherous slaying of his only son; instead, he would scatter” them in a Diaspora throughout the world. By the time Augustine was writing, in the fourth century CE, it seemed that history had amply fulfilled that prophecy. Didn’t the destruction of the Temple in 70 AD, followed by the razing of Jerusalem itself by the Emperor Hadrian, demonstrate God’s wrath at his formerly chosen people?Even in this dire vision of Jewish history, however, Fredriksen finds reason to be hopeful. God’s plan might involve the exile and suffering of the Jews, but this punishment itself was proof of God’s continuing interest in the fate of Israel. Judaism still had a role to play in the unfolding of God’s providence, as the unwilling, unwitting witness to the truth of Christianity. Augustine wrote that the Jews served Christianity as a scrinaria, literally a case for carrying books or papers—in this instance, the books of the Hebrew Bible. The Bible, to Christian eyes, was nothing but an extended allegorical prophecy of the coming of Christ, and it was the task of the Jews to verify that prophecy by spreading the Bible throughout the world. The fact that the Jews themselves did not read their Scripture this way—that they did not, for instance, see Psalm 59 as a prophecy of their own dispersion—only made them, in Augustine’s eyes, more effective witnesses for Christianity. “The believing Gentiles,” he explained, “cannot suppose that these testimonies to Christ are recent forgeries, for they are found in books held sacred for so many ages by those who crucified Christ, books still venerated by those who blaspheme him.” The Jews “testify to their truth by not understanding them.”“The Jews as Jews,” Fredriksen summarizes, are thus the servants of the Church.” This meant that the Church should not attempt to extirpate Judaism, either by slaying” the Jews or by forcing them to convert en masse. Here Augustine drew a second biblical parallel that would prove very influential in the Church’s treatment of Jews. The Jews who killed Jesus, he proposed, were like Cain, who killed his brother Abel. In Genesis, however, God specifically prohibits anyone from taking vengeance on Cain for his crime: “The Lord God placed a mark upon Cain, lest anyone coming upon him should kill him.” Just so, Augustine argues, the Jews bear their own mark of Cain—their law, the Torah, “which distinguishes them from all other nations and peoples.” God means for the Jews to bear that law until the end of time, as a symbol of their permanent exclusion from Christian grace.It is a gauge of the dismal history of Christian anti-Judaism that this Augustinian “witness doctrine” was, in fact, a notably positive development. To explain why comparing the Jews to Cain, the archetypal murderer, was in fact an act of laudable philo-Semitism, Fredriksen must take the reader on a difficult but fascinating journey through the complications of early Christian thought. She introduces the various schools that competed for Augustine’s intellectual allegiance, in particular the Manichees, who identified the God of the Hebrew Bible with the evil deity who made our fallen world. Faustus, a Manichean preacher whom Augustine challenged in a famous debate, considered the Jewish God no better than the pagan gods of Olympus—”greedy for blood and fat from all kinds of sacrifices, and jealous if these were offered to anyone other than himself.” Such varieties of Christianity sought to completely sever the faith from its Jewish past—to deny that Jesus had anything to do with Judaism, except as its opponent and destroyer.Augustine’s great contribution to Catholic theology, Fredriksen shows, was to insist that the Church preserve and honor its Jewish heritage. He argued that Catholics and Jews recognize the same God, that Israelite sacrifices were divinely ordained and pleasing to God, and that the first generation of apostles, including Paul and Peter, were themselves observant Jews. Indeed, as Fredriksen shows in the best parts of Augustine and the Jews, Augustine’s “defense” of Judaism was bound up with his most adventurous thinking about time, language, and free will.Yet while Augustine and the Jews is a marvelous work of scholarship, it never quite manages to pry those quotation marks off the word defense.” Finally, what Augustine offered Judaism was the fate that the damned are meant to suffer in the Christian Hell: not annihilation, but perpetual torment, inflicted by God in execution of his inscrutable judgment. Reading Fredriksen is a powerful reminder that, while today’s Christian ecumenism is admirable, there can never be a secure or happy home for Jews in a society dominated by Christianity. That is why American secularism and pluralism have made it possible for American Jews, for almost the first time in history, to wipe off the mark of Cain and be seen as and for themselves.