The name of the ambitious new series of short books just launched by W.W. Norton is “Issues of Our Time,” but it could more honestly have been called the September 11 series. The titles of the first three volumes – “Cosmopolitanism,” “Preemption,” and “Identity and Violence” – neatly define the galaxy of quandaries and anxieties unleashed by the terrorist attacks, which transformed America’s intellectual climate as surely as its political climate. Those titles sound abstract enough, but it is not hard to see behind them the same questions asked by journalists and ordinary citizens in the aftermath of September 11: Why do they hate us? Is Islam a violent religion? And, above all, how do we stop them from attacking us again?

The idea of bringing our leading public intellectuals together to answer those questions is a good and timely one, and “Issues of Our Time” has an impressive roster of contributors. Indeed, just as the Church of England was once called the Tory Party at prayer, so “Issues of Our Time” could be described as Harvard University at work. The series is edited by Henry Louis Gates Jr., professor of the humanities at Harvard, and the first three books are written by Amartya Sen, Harvard professor of economics; Kwame Anthony Appiah, former Harvard professor of philosophy (now at Princeton); and Alan Dershowitz of Harvard Law School. Future Cambridge-based contributors include Louis Menand, William Julius Wilson, and Charles Fried.

To the extent that the people behind “Issues of Our Time” represent America’s academic elite, then, the series has a symptomatic importance beyond the value of each individual book. In the 1920s, when the Enlightenment heritage of democracy, tolerance, and progress was first challenged by totalitarianism, Western intellectuals spectacularly failed to meet the crisis. The reputation of the intellectual has never fully recovered from what Julien Benda named “le trahison des clercs” – the seduction of the articulate classes by the ideologies of fascism and communism. Now that the challenge of illiberalism has returned in the perplexing new form of Islamic fundamentalism, how do our own clerks acquit themselves in responding to it?

Judging by the first three books in “Issues of Our Time,” the answer is: honorably, but not effectively enough. The problems that Messrs. Sen, Appiah, and Dershowitz grapple with are all parts of one fundamental question: How does an open, pluralistic society cope with an enemy determined to turn our strengths into weaknesses? This is anything but an academic question today, when so many major issues – from warrantless wiretapping to coercive interrogation to the occupation of Iraq – turn on the balance between security and liberty, tolerance and vigilance. Clearly, these books would not have been written or published if it were not for our urgent interest in such problems.

Yet if these sane and learned books have a common flaw, it is their reluctance to come to grips with the true difficulty of those problems – to go beyond liberalism’s comfort zone. In different ways, Messrs. Appiah, Sen, and Dershowitz remind us of why we cherish pluralism and the rule of law; but they do not tell us how to preserve those values when they are under threat.

Amartya Sen, winner of the 1998 Nobel Prize in economics, is the most illustrious of these authors, which may be why “Identity and Violence: The Illusion of Destiny” (224 pages, $24.95) is the most disappointing of the three books. Mr. Sen has one important idea to drive home, the same one he has advanced more thoroughly in previous books and in his essays in the New Republic. It is that the reduction of human beings to members of one or another monolithic “civilization,” Samuel Huntington-style, is not just morally pernicious, but historically stupid. “Civilizational or religious partitioning of the world population,” Mr. Sen writes in his academic’s prose, “yields a ‘solitarist’ approach to human identity, which sees human beings as members of exactly one group. … A solitarist approach can be a good way of misunderstanding nearly everyone in the world.”

In particular, Mr. Sen argues, to cast today’s geopolitical strife as a conflict between Western and Islamic civilizations, each subscribing to a unitary worldview, is a travesty of both fact and logic. Against this kind of essentialism, Mr. Sen reminds us of some useful historical complications. Democracy, he writes, is not an exclusively Western invention; India, Persia, and Africa all have democratic traditions to build on. Neither are science and technology a Western monopoly; Indian mathematics, Arabic philosophy, and Chinese inventions all helped to fuel the European Renaissance. More important still, no individual today is purely and simply “a Westerner” or “a Muslim”: Our identities are all influenced by nation, class, occupation, gender, and a host of other factors beyond geography and religion. Only a sick society tries to convince its members that only one of their identities matters.

The point is absolutely true, so far as it goes; the problem is that, even in this short book, Mr. Sen does little more than reiterate it, without going into its ramifications or answering potential objections. The most obvious of those objections is suggested by Mr. Sen’s example (repeated several times) of the multiple identities one person can claim: “The same person can be, without any contradiction, an American citizen, of Caribbean origin, with African ancestry, a Christian, a liberal, a woman, a vegetarian, a long-distance runner, a historian, a schoolteacher, a novelist, a feminist, a heterosexual, a believer in gay and lesbian rights, a theater lover,” and so on.

The problem is that such a moral (and physical!) exemplar is the last person who would need to be convinced of the joys of hybridity. Such a person – a privileged, cosmopolitan intellectual – is more likely to be the target of those who do not delight in multiplicity; of those who hate African-Americans, or who believe that women should wear a veil, or who find homosexuality immoral. Mr. Sen offers little insight into the reasons why some people prefer a “solitarist” identity and refuse any attempt at complication.

More, he discounts the extent to which our own identities can be forcibly reduced by our enemies’ simplifications.You may not think of yourself solely as an American, but if you are likely to be killed solely for being an American, Americanness inevitably moves to the forefront of your identity. Mr. Sen’s policy prescriptions – about Third World debt relief and the importance of secular state education – are entirely reasonable, but they do not make up for the absence of a real engagement with the principles that oppose his own.

The difficulty of responding liberally to illiberalism is also the central dilemma of Kwame Anthony Appiah’s “Cosmopolitanism: Ethics in a World of Strangers” (256 pages, $23.95) the best, and best-written, book of the series so far. Mr. Appiah draws on autobiography and contemporary philosophy to sing the praises of cosmopolitanism, a term that still carries a whiff of elitism. Mr. Appiah uses it,nonetheless, because he wants to emphasize two complementary ideas: “the idea that we have obligations to others,” and “the value not just of human life but of particular human lives.”The first of these principles, however, sounds less like cosmopolitanism proper than a kind of Kantian universalism, and it plays a secondary role in Mr. Appiah’s argument.

The pleasures, rather than the duties, of cosmopolitanism are Mr. Appiah’s real subject, and he knows them firsthand. Born in Ghana to a Ghanaian father and an English mother, Mr. Appiah is at home on three continents, and he has a nuanced sense of how people from different cultures can and do actually get along. This helps to inform his philosophical analysis of relativism, the notion – now less popular than it was during the early-1990s heyday of multiculturalism – that people with different backgrounds can never meaningfully discuss questions of morality, since their basic principles are irreconcilable.

It is true, Mr. Appiah concedes, that people with different worldviews can seldom convince one another about principles – or, for that matter, about facts, as he notes in a discussion of Ghanaian beliefs about witchcraft. But they can still have fruitful discussions, because certain values are shared across cultures – kindness, politeness, hospitality – even if they are interpreted differently in different places. And discussion, Mr.Appiah writes, is itself an important good: “Conversation doesn’t have to lead to consensus about anything, especially not values; it’s enough that it helps people get used to one another.”

Here again, however, a sound liberal principle can look awfully brittle, even effete, next to the violent certitude of its enemies. Conversation with strangers, after all, does not really appeal to most people; only the very educated or the very secure tend to be good at it. And since these are precisely the people who are most likely to read a book such as “Cosmopolitanism,” Mr. Appiah’s praise of “conversation” is really a case of preaching to the choir.

But it is worth noting that there is a kind of tolerance, or simply benign indifference, that can exist without active cosmopolitanism. Most Americans do not know any Muslims, for instance, but they have absolutely no interest in interfering with Muslims’ lives, or impugning their faith and culture. Americans might have disliked the Taliban’s treatment of women, for instance, but no one would ever have thought of sending American troops to Afghanistan to do away with burkas. It was only September 11, and the realization that those we tolerate do not tolerate us, that made us willing to go to war against Islamic fanatics. It is the people Mr. Appiah calls “counter-cosmopolitans” – the puritanical terrorists who bomb nightclubs in Bali and Haifa – that pose a threat to American openness, and not vice versa.

How to respond to that threat is the subject of Alan Dershowitz’s “Preemption: A Knife That Cuts Both Ways” (192 pages, $24.95), a book that is at once full of information and frustratingly vague.”Preemption” is not exactly a pleasure to read – full of digested history and repurposed editorials, it clearly was written at speed. But its basic argument is a useful and timely one. Traditionally, Mr. Dershowitz writes, both our law enforcement and our foreign policy were devoted to deterring wrongdoers. Crimes were to be punished only after they were committed, in order to discourage future lawbreakers; Soviet aggression was to be discouraged in advance by the threat of massive nuclear retaliation.

In the post-September 11 world, however, both kinds of deterrence have become problematic.Terrorist crimes, unlike garden-variety murders or robberies, are potentially so destructive that we cannot afford to wait until they are committed in order to punish their perpetrators; they have to be prevented in advance. Likewise, rogue governments such as Iran’s are not amenable to ordinary deterrence, since they do not base their policies on rational calculation. It may be necessary, therefore, to attack them pre-emptively, in order to remove their capacity for violence – as Israel did in 1981 when it bombed the Iraqi nuclear reactor at Osirak, and as America claimed to be doing in 2003 when it invaded Iraq in search of Saddam’s elusive WMDs.

Using concrete examples, most (perhaps too many) drawn from the history of the Israeli-Arab conflict, Mr. Dershowitz shows that preemption can be a vital and necessary tool of statecraft. The Israeli decision to launch a preemptive first strike on Egypt in 1967, for instance, was crucial to its victory in the Six-Day War; conversely, Israel’s reluctance to strike first in the Yom Kippur War led to terrible casualties. Mr. Dershowitz concludes, convincingly, that “no option, not even full-scale preventive war, should be taken off the table if the dangers are grave enough.” One of the potential costs of the Iraq war, which Mr. Dershowitz opposed, is that it may leave us unwilling or unable to act pre-emptively against other, greater threats, such as Iran’s nuclear program.

The use of pre-emption in foreign policy, however, is less controversial than the domestic legal shift from punishing crimes to preventing them. This goal, announced by the Justice Department immediately after September 11, is obviously urgent – not least because the effect of another such terrorist attack on our civic freedoms would be dire. But as Mr. Dershowitz argues, many of our current counterterrorism efforts, from NSA wiretapping to the indefinite detention of noncitizens, are taking place in a legal void.

In the most novel and useful section of “Preemption,” Mr. Dershowitz draws on the history of English common law to show that this sort of improvised jurisprudence is anything but new. Whenever the formal law could not deal with a social threat, he writes, some informal mechanism has arisen to supplement it. England’s justices of the peace long had the power to put people in jail without charge if they were suspected of being a threat to the public. Similarly, our U.S. attorneys are now detaining suspects on material witness warrants or immigration irregularities, because straightforward preventive detention is not provided for in the law.

When it comes to concrete legal reforms, however, Mr. Dershowitz is disappointingly silent. He concludes that we need “to articulate a consistent and workable jurisprudence of anticipatory governmental action,” but exactly what such a jurisprudence would look like, and how it might curtail our traditional civil liberties, he does not say. Like Messrs. Sen and Appiah, Dershowitz seems to fall silent just where the problems facing us are most acute, and least amenable to the traditional practices of a free society. For the “Issues of Our Time” series to make a real contribution to America’s public debate, it needs to spend less time reminding us of what we already know, and more time exploring what we are afraid to confront.

akirsch@nysun.com