A grand, tragic instance of an operation that succeeded though the patient died: German Jewry was dispersed or annihilated, but its synthesis of traditional religion and Western modernity ""meant a new beginning and a secure foundation for Jews both as individuals and as a community."" Hans Bach was a German Jew, a literary scholar and editor (Der Morgen, Synagogue Review of Great Britain), whose own distinguished life illustrates the thesis he defends here--which ignores some serious arguments against it. Bach begins his survey, inevitably, with Moses Mendelssohn (who all but equated Judaism with reason) and ends with the quartet of Hermann Cohen, Leo Baeck, Martin Buber, and, most important, Franz Rosenzweig (who managed to be a liberal yet orthodox in his ""care for traditional values"" and a Zionist yet uncommitted to any particular form of Zionism as an end in itself). Bach takes Rosenzweig's Star of Redemption (1921) as the culminating achievement of the third such major creative fusion (the first being Maimonides' blend of Greek and Jewish thought, the second the Jewish culture of medieval Spain) in the history of Judaism. Bach himself admits the bothersome symbolism of the fact that all Moses Mendelssohn's children except his oldest son apostasized. But he seems reluctant to come to terms with the characteristic atheism or agnosticism or detachment from Judaism of the outstanding Jewish minds of the last two centuries, both inside and outside Germany: Marx (whom Bach scarcely mentions), Heine (a unique sort of self-mocking deist), Freud, Kafka, Proust (regally Jewish), Einstein, Levi-Strauss, etc. Significantly, Bach faults Zionism for failing to acknowledge ""the Jewish values of the age of emancipation"" and for breaking the ""sense of continuity in the development of Jewish life."" Given the almost undisputed triumph of Zionism after the Holocaust, this suggests that Bach's vaunted synthesis, however splendid in itself, may not be as universal and enduring as he would have it. Still, this is weighty intellectual testimony in a complicated case.