Nearly six years ago, well before his surprising selection last month as chancellor of the Jewish Theological Seminary, Arnold Eisen authored a book about the state of American Jewry. The Jew Within, his collaboration with Steven M. Cohen, exuded all the statistical detail and willful dispassion of the traditional social scientist. With persuasive detail and insistent neutrality, Eisen of Stanford and Cohen of Hebrew University depicted the disengagement of their sample of "moderately affiliated" baby-boomers from the formal organizations and communal bodies of organized Jewry. Their memorable contribution to Jewish discourse was the phrase the "sovereign self." For those sovereign selves, as they wrote, "Eclecticism is now the rule when it comes to practice. Consistency is no longer prized. Theology is virtually irrelevant." The most important element in their Jewish lives, other than their own families, was the concern with American anti-Semitism, that most exaggerated of terrors, which placed well ahead of such factors as God, the Torah, the Holocaust and Israel. With the exception of a stray phrase here and there in the book's 242 pages, The Jew Within revealed virtually nothing of what the two authors made of this state of affairs. Eisen and Cohen's own prose seemed to be as resolutely non-judgmental as the I'm-OK-if-you're-OK boomers they chronicled. Yet at roughly the same time his book appeared, Eisen wrote a brief essay on the subject of "Rebuilding Jewish Communities" for the journal Sh'ma, and in its six paragraphs he reduced the sauce of The Jew Within to its tangy essence. It became clear, reading Eisen in this enforced concision, that he was anything but relativistic about the inward turn of American Jewry. He approvingly cited, for instance, a book and author that had gone entirely unmentioned in The Jew Within - Bowling Alone by Robert Putnam. Using the example of the demise of bowling leagues, Putnam argued that America in the past generation had neglected the "social capital" of voluntary associations, becoming a more privatized and atomized nation. Eisen also made reference, as he had in The Jew Within, to Robert Bellah, the University of California sociologist whose book Habits of the Heart anticipated Putnam's work by about 20 years. On the subject of religion, Bellah's volume included the tragic and hilarious account of a woman named Sheila who cobbled up her disparate beliefs into a personal faith she called (not to be too narcissistic about it) "Sheila-ism." Turning to the Jewish version of Sheila-ism, Eisen in the Sh'ma essay spoke with welcome bluntness. "I don't see how attempts at Renaissance [capitalization his] can succeed outside the framework of such communities - or, frankly, why they should," he wrote. "We are here to buildâ€¦communities of caring, justice, and learning - in my terms, communities of Torah." IN A speech in 2000 to the Jewish Council for Public Affairs, Eisen sounded a similar message. "The phenomenon of Jews who identify subjectively with the Jewish people and its culture, but do not observe any of the tenets or practices of Judaism and do not affiliate in any tangible way with the Jewish people, via its local organizations and communities, is to my mind quite worrisome," he said. "In the long term, this tendency spells disaster." The tone of alarm within a habitually modulated voice may be the most hopeful sign in Eisen's assumption of the leadership of JTS. American Jews are living in an age of "post-denominationalism," to use the trendy neologism. The phrase refers to something beyond the familiar, recreational sort of "shul-shopping" that has long been a staple of American Jewish life in larger communities. It is more like Judaism's equivalent of the military recruiting slogan, "An Army Of One": A congregation of one, maybe even a denomination of one. As the center body in the American Jewish spectrum, flanked by an Orthodox revival on one flank and Reform's embrace of interfaith families on the other, the Conservative movement faces a real identity crisis. Much of the analysis of the dilemma, including my own, has tended to telescope in on two key issues, the ordination of openly gay and lesbian clergy, and the question of reaching out to gentile spouses of born Jews. Those fault lines remain genuine and important, but Eisen also confronts a more foundational question: Why should the Conservative movement exist at all? What is its purpose in an era of declining allegiance to any denomination, much less one with a chronic struggle to assert what it is, rather than merely what it is not? It would be a major mistake, though, to discount what a movement means even in a fiercely individualistic era. To steal a phrase from a community organizer of my acquaintance, Conservative Judaism means "organized people and organized money." Its seminary educates and ordains rabbis, cantors and educators. It has associations of rabbis and congregations. It oversees the Solomon Schechter day schools and the Ramah summer camps. Its law and ritual committees decide matters of Halacha. Enfeebled and wayward as the Conservative movement might appear, the archipelago of unaffiliated congregations and the multitude of spiritual seekers in American Jewry would have a mighty formidable time building such an infrastructure. And while the Masorti enterprise remains a flyspeck in the binary atmosphere of Israeli Jewry - dati and lo dati - its American parent was the only Jewish denomination in America to adopt Zionism without hesitation. Conservatism's vitality, or lack of it, has a lot to do with American Jewish attachment to Israel now and in the future. Perhaps because Eisen has such a supple feel for the diffuse and ambivalent flock, the object of his own scholarship, he might be the best interlocutor between the institutional grandeur of JTS and the messily lived reality out in the provinces. He understands the aggrievement and estrangement without consecrating it. This student of disorganization, if he rises to the challenge, could turn out to be the consummate organization man. The writer, a professor of journalism at Columbia University, is a regular columnist for The Jerusalem Post. His books include Jew vs. Jew: The Struggle for the Soul of American Jewry.