What exactly are the Jews? The question baffles the layperson and the scholar alike. If we define them as adherents to a religion, then how can there be Jews who are secular (as most in America are)? And why all the signs of ethnicity—the resistance to intermarriage, the characteristic foods and modes of humor, and the focus on the State of Israel, for example? But if we define the Jews as an ethnic group or race, then why all the religious practices and institutions? And what are we to make of the possibility that a gentile can become Jewish, whereas a white person, for example, cannot become black? If, building upon the importance of the State of Israel, we define the Jews essentially as a nation-state, how shall we account for the fact that most of them do not live there and about 20 percent of Israel’s citizens, in turn, are not Jewish? When it comes to the Jewish people, our convenient categories fail us.

In How Judaism Became a Religion: An Introduction to Modern Jewish Thought (Princeton University Press, $27.95, 224 pp.), Leora Batnitzky, one of the foremost scholars of modern Jewish thought, shows that the problem is one that Jewish thinkers themselves have pondered for about two and a half centuries. It is, she demonstrates, characteristic of modernity itself. Earlier, “Judaism and Jewishness were all these at once: religion, culture, and nationality.” What severed this unity and, more particularly, brought into existence the idea that Judaism/Jewishness constitutes a religion is “the historical fact of the modern nation-state” and “the notion that religion and politics comprise, and ought to do so, separate realms of human life.” Batnitzky organizes her book around the widely varying responses to this momentous change of an equally wide range of Jewish thinkers, religious (in all shades) and secular, Zionist, non-Zionist, and anti-Zionist, German, Eastern European, American, and Israeli. The presence after each chapter of helpful bibliographies, briefly but expertly annotated, adds to the high value of the volume.

Batnitzky’s tale begins with Moses Mendelssohn (1729–86), and, to adapt Alfred North Whitehead’s celebrated observation about Plato, she sees modern Jewish thought as a series of restatements of, and reactions to, Mendelssohn’s innovative claims. Mendelssohn addressed a situation in which the process of Jewish emancipation had begun in German lands, but without the corresponding social and cultural integration into the majority population. Indeed, both friends and foes of Jewish emancipation raised troubling questions about the classical, or, as we might say, premodern tradition. What is the status of Jewish law (halakhah) and rabbinical courts in this new arrangement? (Today, not coincidentally, the analogous question about Muslim law is asked throughout the West.) How German can Jews really be if they retain their separate communal institutions and identity and adhere to a religion that most Christians had long seen as carnal rather than spiritual, disastrously focused on the letter rather than the spirit, as either a cause or a symptom of criminality and exploitation, and patently inferior to Christianity? Such attitudes were not restricted to the unlettered; they were also amply attested among the Enlightenment elites, such as Kant and Schleiermacher, to name but two.

Mendelssohn’s ostensible defense of the Jewish tradition actually advocated revolutionary changes in it. Jewish law, he wrote, has no coercive dimension; it is only edificatory and liturgical. It affects the heart and mind only, serving, for example, as the vehicle for Jews to express their gratitude to God and in no way constituting a political entity in tension with the state. Nor does Judaism conflict with Enlightenment thinking, for it demands no beliefs. In Mendelssohn’s view, “the ceremonial laws instead are founded on the historical truth of God’s revelation at Sinai,” Batnitzky writes, “and these ceremonial laws script a particular way of life for a particular people.” They thus exert no authority over the minds of Jews and make no claim at all on gentiles. With this novel separation of Judaism from communal authority, Mendelssohn “would invent the idea of Jewish religion.”

Although Mendelssohn retained his halakhic observance throughout his life, his mixture of traditionalism and Enlightenment did not take hold, even in his own family; four of his six children converted to Christianity. His impact, in fact, proved greatest in the Reform movement, which came into existence a generation after his death and jettisoned most of the traditional observances together with the political dimensions of the tradition. Thus, for Abraham Geiger (1810–74), a brilliant historian and a leading Reformer, what mattered in Judaism was its “spiritual achievements,” for “it is precisely to its independence from political status that Judaism owes its survival.” Echoing the traditional Christian (especially Lutheran) disparagement of Jewish law, he celebrated his own period as one of “liberation” from “legalism.” At the same time, however, Geiger was a pioneer in uncovering the Jewish sources of Christianity (as well as Islam), powerfully undermining Christian supersessionism and the corresponding demand that the Jews convert. Once Christians were freed from their ancient mythologies and prejudices and Jews were freed from their outmoded practices and communal structures, Christians and Jews could confront the exciting new situation as equal citizens of the modern German state, testifying in their different ways to the overarching truths of monotheism and the moral life.

Even apart from the thoroughgoing traditionalists (about whom more later), reactions to Reform came swiftly. Henrich Graetz (1817–91), the greatest Jewish historian of the time (and perhaps ever), believed that traditional law was essential to the identity and survival of the Jews. “Judaism is not a religion of the individual,” he wrote, “but of the community. That actually means that Judaism, in the strict sense of the word, is not even a religion...but rather a constitution for a body politic.” It cannot therefore be reduced to an abstraction like monotheism or anything so vaporous as morality divorced from history and normative tradition. Indeed, it is the study of history that discloses the spiritual power of Judaism and the Jewish people and the deep continuities between ostensibly diverse periods. In Roman Catholicism, perhaps an analogy to John Henry Newman, Graetz’s contemporary, would be in order. In Judaism, his continuity lies with what in Germany was called the Positive-Historical School and in America, Conservative Judaism, which has traditionally put great emphasis on history and peoplehood, less on the particularities of observance, and almost none on theology.

Contrasting with these religious responses to the emancipation of the Jews in Germany (and others Batnitzky discusses) is a set of responses from the Russian Empire, where life for the Jews was on balance harder but a distinct Jewish culture was stronger and more resilient. There, the defining reality was virulent anti-Semitism, especially lethal in the wake of the assassination of Czar Alexander II in 1881. To Lev Pinsker (1821–91), a physician, “Judeophobia [that is, anti-Semitism] is a psychic disorder...and as a disease transmitted for two thousand years it is incurable.... He must be blind indeed who will maintain that the Jews are not the chosen people, the people chosen for universal hatred.” The answer lies not in the liberal route of persuading those whose culture and religion are shot through with anti-Semitism to grant the Jews civic rights nonetheless, but in the Jews’ working actively to (re)create a national homeland of their own. So long as they are vulnerable to the host culture, the host culture will sooner or later attack them. Instead of passively waiting for God’s deliverance or escaping into the study of ancient texts, the victims need to organize in self-defense. It is not religion that will save the Jews but politics.

With the frightening upsurge of anti-Semitism at the end of the nineteenth century in the supposedly enlightened lands of Germany and France, as well as in Russia—and even more after the Nazi annihilation of about one-third of the world’s Jews—Zionism gained strength and credibility, attracting mostly secular Jews but some religious ones too, eliciting from the latter (especially Rabbi Abraham Isaac Kook [1865–1935]) some highly creative theological thinking. But for some of the secularists, such as Ahad Ha’am (“One of the People,” the pen name of Asher Ginsberg [1856–1927]), the renewal of the Jewish people had to be cultural and not only political. As Batnitzky puts it, political Zionism “proposes an external solution, the establishment of a state, while Ahad Ha’am proposes an internal solution, the spiritual rebirth of the Jewish nation.” It was, however, spirituality without a theological foundation.

Unfortunately, Batnitzky’s use of the term “political” is sometimes problematic. One difficulty with it is that the liberal positions that descend from Mendelssohn are not without a political agenda of their own. In the case of American Reform Judaism, for example, theological liberalism has long correlated with an activist agenda in support of “progressive” causes; more recently, it has correlated with advocacy of positions on issues like abortion and homosexual behavior that are at odds with the classical rabbinic teachings. This is not apolitical. It may, rather, be hyperpolitical, for it allows a new sociopolitical vision to displace the traditional religious norms.

Sometimes, when Batnitzky writes “political,” she seems to mean “communal” or “corporate.” Whatever one calls it, the frame within which she views the many modern Jewish thinkers she discusses necessarily constricts her vision and requires her to give short shrift to important dimensions of their thought. This is especially the case with the more theological figures, such as Franz Rosenzweig and Joseph B. Soloveitchik. At times, I found myself wondering whether Batnitzky’s framework has not led her to judgments that are too quick and too sweeping, as when she claims that Soloveitchik (1903–93), the towering figure in Modern Orthodoxy in the twentieth century, “implicitly affirms a Protestant idea that religion is private and individual.” The passage she cites in support of this, alas, says no such thing; rather, there Soloveitchik writes in support of his idea that “Judaism...is grounded in its awareness of and esteem for the individual” and the individual’s capacity to break free of “the teleological law of the species” through halakhah, and not at all through private, idiosyncratic religiousness. And when Batnitzky claims Soloveitchik saw Judaism as “separate from both politics and ethics,” she overlooks not only that enormous emphasis on halakhah (he was, in fact, a highly respected legal authority) but also his religious Zionism and his concern with communal structures.

Beyond her difficulties with Soloveitchik, Batnitzky seems generally averse to the more traditional religious responses to emancipation and too eager to make the highly dubious claim that Orthodoxy is as much “a modern invention” as the other varieties of Judaism in modern times. Noting, for example, the successful effort of Samson Raphael Hirsch (1808–88), leader of the Orthodox community in Frankfurt, “to establish a separate community by seceding from the Jewish community recognized by the state,” she concludes that “Hirsch makes Judaism more like the Christianity of his time...relegating itself to private, confessional status” and thus “leaves room...for a kind of religious pluralism, despite his disdain for Jews who are not Orthodox.” But in Hirsch’s mind, the basis for the authentic Jewish community lies in something not private but public, not confessional but objectively historical—the revelation of the Torah and the normativity of its rabbinic interpretation. As he puts it, “the Law of God that Moses brought down to us...is also the only standard for testing a Jewish community to see whether it is truly Jewish.” This is as far from religious pluralism as one can get. That the adherents of the traditional law and theology in Hirsch’s time found themselves in a novel situation, with the emergence of organized alternatives, can be readily granted, and so can the fact that some rather untraditional and historically inaccurate notes can be seen in his writing. But none of this justifies Batnitzky’s claim that “Hirsch’s Orthodoxy is...the most modern of modern Judaisms.”

The same tendency can be found in her claim that “ultraorthodoxy is of course just as much modernity’s child” as all the other movements and schools of thought. As an example, she cites one of its founders, Moses Sofer (1762–1839), also known as the “Chatam Sofer” after one of his books. Sofer famously quoted a Talmudic saying that “anything new is prohibited by the Torah.” In its original context, the saying relates to Leviticus 23:14, which forbids the eating of new grain before a sheaf of it has been offered in sacrifice. That Rabbi Sofer invoked the saying, for the first time, in opposition to legal and liturgical innovation strikes Batnitzky as a contradiction. How could a fierce opponent of innovation come up with something new? Exegetical innovation, however, had long been esteemed in Judaism and continues to be practiced in ultraorthodoxy (among others) to this day; it in no way contradicts a rigid commitment to the authority and totality of premodern Jewish law. The interaction of fidelity to received norms and interpretive innovation in Orthodox Judaism is much subtler than the familiar modernist (and rather Protestant) dichotomy of an encrusted past and a responsive present can accommodate. In any living tradition, past and present interact in a way that a model of simple temporal succession is bound to miss.

For Batnitzky, the mere fact that a community exists in, and responds to, the modern world makes it “a modern invention” and even “modernity’s child.” Perhaps an analogy to Christianity can clarify the weakness in this way of seeing things. It is obvious that the Roman Catholic Church has changed dramatically over the centuries, especially in the past two. Modernity has clearly altered it—if not in its dogmatic core, then certainly in its apologetic strategies, institutional structures, and political relationships. But would it be reasonable to say that Roman Catholicism is therefore every bit as much a creature of modernity as, say, Unitarian Universalism? The historical reality in both the Christian and the Jewish cases calls for a subtler and more nuanced analysis, one that recognizes that modernization occurs across a spectrum and the past, to one degree or another, lives on in the present.

What historical analysis cannot tell us, however, is whether the truth about the Jews is found in the more or the less traditional versions of Judaism, in the more communal or the more individualistic thinking, or in the religious or in the secular understandings of Jewishness. To answer that question, one must step outside the constraints of historical description and venture into the world of constructive thought. For anyone who wishes to understand the history of the question and the answers that have already been proposed, Leora Batnitzky’s stimulating book is an excellent place to start.