My favorite saying about my fellow Jews emphasizes not our tenacity or our piety but something much more important: our passion for disagreement. “Two Jews, three opinions,” a rabbi once told me during one of my periodic bouts of religiosity. The rabbi’s maxim often wafted into my mind in a slightly revised form while I was in graduate school, pursuing a PhD in the most querulous discipline in the academy. “Two philosophers, 10 opinions,” I thought when I witnessed my peers exchanging spirited arguments in seminars, or when my adviser returned my papers with a Talmudic barrage of comments in the margins. I was flattered by his strenuous opposition, of course. To a philosopher, as to a Jew, there is no insult as grave as placating assent, no tribute as great as a detailed rebuttal.

I am tempted to dispute almost every claim in “Liberalism as a Way of Life,” a stirring new book by the political philosopher Alexandre Lefebvre, and that is how I know I admire it. There is much worth protesting in this daring and engrossing salvo only because there is much worth considering.

At first glance, Lefebvre’s project may seem unfashionable, if not downright hopeless. For years, the ideology he aspires to resuscitate has been limping along, lamely parrying attacks from all quarters while steadily losing cultural purchase. Critics on the right lambaste liberalism for rejecting tradition, while detractors on the left lament its tepid incrementalism and the cruelty of its economic policies. Even its defenders can muster only a feeble case in its favor. At innumerable yet somehow identical roundtables, on podcasts and in magazines, we hear from the same uninspired apologists. Francis Fukuyama, now 71, insists against all the evidence that old-fashioned liberal democracy is bound to prevail; Cass Sunstein, two years Fukuyama’s junior, urges us to take comfort in our fraying rights.

In this stale intellectual atmosphere, a spate of new pleas for a battered ideology provides a breath of fresh air. Books like “Liberalism Against Itself” (2023), by Samuel Moyn, and “The Lost History of Liberalism” (2018), by Helena Rosenblatt, have attempted to rehabilitate the tradition by returning to its older and more rousing incarnations: Drawing on historical sources, Moyn and Rosenblatt demonstrate that liberalism was once more of an all-encompassing ethos and less of a laissez-faire enterprise.

Lefebvre takes a different tack. “It is easy to lose sight of how extraordinary liberalism is,” he writes. His aim is to remind us of its promise — not by turning to the past but by asking us to take stock of the values in which we are marinating in the present. If we reflect honestly on our own convictions, he believes, we will find that we already accept the remarkable philosophy fortifying the shaky fortress of the Western experiment. Who among us does not agree that “every citizen … has a legitimate expectation to be treated reasonably and fairly by the basic institutions of our society”?

“Liberalism as a Way of Life” diverges from its predecessors in another telling respect. Like his peers, Lefebvre recognizes that there is a palpable hunger for a richer liberal vision — but he seeks to provide one by conceding that the philosophy’s most dangerous enemies may be right about it.

The giant of 20th-century political philosophy, longtime Harvard professor John Rawls, introduced the distinction at the heart of contemporary liberalism. In his 1993 classic, “Political Liberalism,” he distinguished between a “comprehensive doctrine,” the personal values a citizen espouses behind closed doors, and “a political conception of justice,” the liberal institutional principles a citizen endorses in public. In his eyes — and in the eyes of his many followers — liberalism exists to maintain a rigid separation between the two. Inhabitants of a liberal state must subscribe to what Rawls called “a fair system of social cooperation” governing public life but are free to follow any particular moral system privately. Diverse comprehensive doctrines — Buddhism, pacifism, asceticism and so on — are all consistent with liberal principles of governance.

Since the publication of Rawls’s opus, the standard liberal line has been that we live (or ought to live) under political, not comprehensive, liberalism. Indeed, if liberalism is only a theory of institutional arrangements, then it isn’t possible to apply its insights to our private lives.

Ever the provocateur, Lefebvre takes precisely the inverse view, suggesting that we regularly exhibit liberal values in our interpersonal interactions but have yet to achieve anything resembling liberalism in the public sphere. Our system of governance and wealth distribution is an impure alloy uniting “liberalism and other ideologies,” among them unfettered capitalism (Rawls called for a dramatic redistribution of wealth) and meritocracy (a setup that disproportionately rewards talent, creating hierarchies that Rawls would have rejected). A society that satisfied Rawls’s stringent standards, Lefebvre writes, “would be nearly unrecognizable.” Still, “that liberalism is not, and should not be, a philosophy of life or comprehensive worldview … is taken for granted,” at least by liberalism’s foremost champions in the academy.

Some of the philosophy’s most alarming antagonists, however, argue that there is no schism between private morals and public commitments. The Christian reactionaries who deem themselves “post-liberals” conceive of liberalism “only secondarily in terms of legal and political institutions,” Lefebvre writes. “Much more significant is liberalism as a worldview and a value system.” In Pride parades and grade school classrooms, in abortion clinics and gay bars, paranoid post-liberals see the hand of their all-powerful nemesis at work. “One hallmark of liberalism is a kind of organized bad faith,” writes one of their most prominent representatives, the ultraconservative Catholic Adrian Vermeule. “Even to itself, it denies its own substantive character.” In other words, liberals refuse to acknowledge that political liberalism gives rise to private libertinism.

Though this conclusion is de rigeur among the right-wing religious crowd, none of their brigade has managed to articulate it in precise (or even non-hysterical) terms. After reams of the post-liberals’ portentous obscurities, Lefebvre’s cutting clarity comes as a relief. At last, someone has developed a rigorous, unsentimental vocabulary with which to probe the relationship between the moral and political strains of the liberal tradition. Can the two be disentangled? Must liberal political institutions give rise to a liberal cultural life? Is a liberal cultural life a prerequisite for liberal political institutions? And what is liberal culture, exactly?

These are crucial and carefully posed questions, even if I do not always buy Lefebvre’s answers — particularly when he finds himself in lockstep with the likes of Vermeule. He adopts a different tone, of course, but he, too, accepts that liberalism is the defining force in our society, that it is “at the root of all things us. What we find funny, outrageous, or meaningful; how we comport ourselves in friendship or romance; and the ideals that we set for ourselves as citizens, professionals, neighbors, and family members.”

This is an unprecedented admission coming from a liberal theorist, although a superficially similar point has been made before, most famously by the Oxford political philosopher G.A. Cohen. In an influential rebuttal to Rawls that he developed throughout the 1990s, Cohen suggested that comprehensive liberal ethics are necessary for political liberalism to function: If citizens in a liberal polity do not embody certain liberal values in their private lives, then liberal institutions will crumble. Lefebvre emphasizes that his thesis is different: He is not asking “which virtues are required for liberal democracy,” but “which virtues are — or more broadly, which way of life is — imparted by liberal democracy.”

And his conclusion is: ours. Our penchant for fairness, our sense of social obligation, our disgust in the face of brutality, our taste for television shows like “Parks and Recreation,” our abhorrence of hate speech — all are part and parcel of our liberal inheritance. Given that we are already comprehensive liberals, albeit sometimes closeted ones, Lefebvre’s ambition is to furnish us with “spiritual ” and “existential” reasons to embrace what we are. Liberalism makes us fairer and less pretentious, he explains. It might even make us “light, ironic, fun, and playful.”

Lefebvre’s book is certainly fun and playful, but the case it makes for liberalism will persuade only those who are already immersed in the culture he describes. Is he right that we are stewing in such a uniformly liberal brew?

He offers two arguments to support this contention, and neither of them is entirely convincing. First, he holds that liberalism accounts for our ethical reflexes; second, he maintains that many of our best-loved artistic artifacts are intelligible only against a backdrop of comprehensive liberalism. To illustrate the first claim, he asks us to consider a person who uses vicious slurs. Liberalism, he tells us, is at the root of our ensuing indignation: “What else could account for your visceral spark of anger, your flush of outrage?” I am not inclined to respond to this rhetorical prompt the way he expects. Countless alternative ethical frameworks, from feminism to Christianity, can vindicate my revulsion. To assume that liberalism is the only system that can justify or explain an abhorrence of bigotry is to ignore a wealth of moral traditions that are at least equally formative.

To show that liberalism informs our cultural consumption, Lefebvre points to public-minded TV series like “The Good Place” and “Parks and Recreation.” Reading his praise for these shows, I wondered if liberalism has fallen out of favor because of its glibly upbeat aesthetics: If these cheerful, cheesy shows are the foremost artistic achievements of the tradition, then perhaps it deserves to burn.

But even if I contented myself with liberalism’s banal cultural offerings, “Parks and Recreation” and “The Good Place” are hardly representative of the range of popular entertainments in circulation. What about superhero movies, which depict a hierarchical world in which coteries of natural aristocrats battle to save the lowly populace? What about “Game of Thrones,” which brims with bloody battles and courtly intrigues that tempt us to monarchist nostalgia? What about “The Bachelor,” an homage to the sclerotic romantic mores of the 18th-century marriage plot?

Perhaps more important, I’m not sure that “being liberal is an intrinsically fulfilling, generous, and fun way to be,” as Lefebvre so optimistically promises. Virtues of liberal institutions, such as objectivity and evenhandedness, cannot be seamlessly imported into emotional life without some disturbing costs. Lefebvre gushes that comprehensive liberalism might encourage “me to step outside myself and be a little less gripped by the me-ness of me.” But someone who was impartial all the way down would be an impersonal kind of person — the sort without prejudices, sure, but by the same token, the sort without entanglements and loyalties. The state should not be permitted to play favorites, but what kind of people would we be if we were not biased in favor of those we loved? What if I want to be gripped by the me-ness of me, and the mine-ness of my aversions and affections?

Lefebvre and I can tussle over the desirability of comprehensive liberalism — and enjoy our tussling — precisely because we live (for now, anyway) in a liberal society: because there is no single set of values that we are forced to share. We are both liberals, but we are not alike. And perhaps that is enough to redeem the whole endeavor.

The liberal philosopher Isaiah Berlin anticipated that this conclusion might prove deflating for those in search of a more grandiose resolution. “Promoting and preserving an uneasy equilibrium” between clashing groups is “the precondition for decent societies,” he wrote. “A little dull as a solution, you will say? Not the stuff of which calls to heroic action by inspired leaders are made? Yet if there is some truth in this view, perhaps that is sufficient.” Perhaps there is some quiet beauty in it, too.

One assumption of the new wave of apologias for liberalism is that, to keep attracting adherents, the stagnating ideology must be recast as a spiritual enterprise, or a personal therapy, or a grand and invigorating project. But perhaps there is something to be said for a philosophy that is less strident and more minimal. After all, conflict can be a currency of respect, affection and excitement. Liberalism, like philosophy and Judaism, might be justified by the joyous tumult of disagreement that it enables, precisely because it does not dictate the details of televisual taste or private ambitions. Sheer difference can be a delight in its own right.

Two Jews, three opinions. Two liberal philosophers, 40 opinions in the span of a single article. A whole society of political liberals, a whole glorious chaos of dissent. How could we ask for more?

Liberalism as a Way of Life

By Alexandre Lefebvre

Princeton University Press. 285 pp. $29.95