“I don’t think that I ever managed real philosophy,” Michael Walzer says in the interview that forms the last chapter of “Thinking Politically” (Yale University Press, 333 pages, $30), the stimulating new collection of his essays. This may sound like false modesty coming from Mr. Walzer, who is one of America’s leading political philosophers. But in fact, by forswearing the name of philosopher, he is merely trying to give a more precise definition of the kind of thinking he does. “I couldn’t breathe easily at the high level of abstraction that philosophy seemed to require,” he explains. “I quickly got impatient with the playful extension of hypothetical cases, moving farther and farther away from the world we all lived in.” Mr. Walzer’s essays take exactly the opposite approach: They set up camp in the midst of the world we all live in bringing the rigor of political theory to the messiness of political debate. It makes sense that Mr. Walzer is both a professor at Princeton’s Institute for Advanced Study and an editor of Dissent, the left-liberal journal: His theories are always also interventions.

This is true of his major works — books such as “Just and Unjust Wars” (1977), which sought to redefine just-war theory for the post-Vietnam age, and “Spheres of Justice” (1983), which argues from liberal principles for a social-democratic politics. It is all the more obviously true of the essays in “Thinking Politically,” most of which began life as lectures and journal articles. The book offers an informal survey of the major themes of Mr. Walzer’s thought, as applied to some of the major issues of the last 25 years. It is thus a good opportunity to come to grips with the strengths and the limitations of both Mr. Walzer’s political principles and his way of practicing political philosophy.

If the essays in “Thinking Politically” share a single theme, or better, a common tension, it is Mr. Walzer’s effort to reconcile his liberal instincts with his leftist commitments to socialism and cultural relativism. For the contemporary left, as Mr. Walzer recognizes better than anyone, is in important ways at odds with the liberal tradition. Liberalism is a paradoxical creed, in the sense that its prescriptions are mainly negative: It is mainly concerned with what the state may not do to its citizens, and what citizens may not do to each other. As Mr. Walzer writes in “Liberalism and the Art of Separation,” one of the key essays in the book, “liberalism is a world of walls, and each one creates a new liberty.” The wall between church and state is the best known of these, but as Mr. Walzer points out, liberalism is also responsible for erecting walls between the state and the market, between the church and the university, and between public and private life.

Each of these walls is designed to maximize the freedom of the individual. In this way, the negatives of liberalism find their ground in a strong affirmation: the belief that the individual human being is sacred, and further, that the best human life involves the productive and responsible use of one’s liberty. The liberal love of freedom, in other words, is not simply a selfish desire to be left alone, as its opponents habitually portray it. It is a moral commitment, which entails a certain view of human nature and the world.

The problem for Mr. Walzer, as a left liberal, is that the left has never really shared the morality of liberalism, or even credited it. “The art of separation has never been highly regarded on the left,” he acknowledges, “especially the Marxist left, where it is commonly seen as ideological rather than a practical enterprise.” To the left, the liberal love of freedom is a self-deception, designed to obscure the fact that the material conditions of life leave most men unable to enjoy their freedom. The danger of this conviction is that, once the love of freedom is discredited, freedom itself usually follows, as the history of the last century shows again and again. And when freedom is lost, equality — which was supposed to take its place, in the Marxist vision — also disappears, since without the liberal respect for the individual, there is no basis on which to erect equality.

Mr. Walzer’s goal in these essays is to argue that liberal values can and should be preserved in leftist politics. This argument has two bearings: the economic, where it means reconciling market freedom with the welfare state, and the intellectual, where it means reconciling liberal certainties with moral relativism. His determination to defend the liberal tradition is what makes Mr. Walzer one of the most honorable figures on the American left. (It also helps to explain the intellectual courage that has characterized Dissent in the years since September 11, 2001, as the magazine has fought against the moral derangement of the left. A fine example is the essay by Mitchell Cohen, Mr. Walzer’s co-editor, currently up on the magazine’s Web site: “Anti-Semitism and the Left that Doesn’t Learn.”)

“Thinking Politically” also makes clear, however, that big stumbling blocks remain in Mr. Walzer’s path. Take, for instance, his view of liberalism as “the art of separation” — an idea he develops at greater length in “Spheres of Justice.” Rather than view state regulation as an infringement on liberty, Mr. Walzer argues that it is actually an aid to liberty, broadly understood. That is because success or failure in the market has a tendency to spill over to every other sphere of life, affecting one’s freedom in matters of family, education, religion, and politics. The ethical passion of Mr. Walzer’s thinking stems from his indignation at the way poverty, in a capitalist society, deprives the poor of every kind of liberty, thereby nullifying the promise of liberalism. As he writes in “Exclusion, Injustice, and the Democratic State,” “all those social transactions that drive citizens toward the margins, that produce a class of excluded men and women — uneducated, unemployed, unrecognized, and powerless — are everywhere and always in the life of the community unjust.”

The conclusion is unimpeachable, but the implications remain unclear. Mr. Walzer takes for granted that the way to remedy the injustice of exclusion is an expansion of state power. Even assuming that this is the case, surely the devil lies in the details: What uses of state power genuinely increase liberty? For Mr. Walzer, the New Deal seems to provide the ideal model, and he displays an almost nostalgic affection for the brawny slogans of “industrial democracy.” (“‘The union makes us strong!’ is a democratic maxim,” he writes, and the very exclamation point is sentimental.) But the sharp decline of unionism in America, and the rise of global competition, makes labor unions a dubious model for re-energizing social democracy. Mr. Walzer’s affection for activists of all kinds — “part-time union officers, movement activists, party regulars, consumer advocates, welfare volunteers,” as he puts it in one catalog — clearly leads him to privilege the activists’ intentions over the results of their agitation. It would take a still more empirical political thinker than Mr. Walzer to determine at what point the expansion of state power ceases to serve individual freedom.

Mr. Walzer’s robust faith in social democracy, however, suffers an odd debilitation as soon as it leaves the borders of the United States. Many of the essays in “Thinking Politically” ask whether the fruits of Western liberalism can be shared with foreign cultures which do not share its basic premises. This is anything but an academic question today, when the Western confrontation with Islamic fundamentalism has forced us to ask whether our liberal principles can and should be defended around the world.

Mr. Walzer’s response to this challenge is to try to formulate an extremely stripped-down version of liberalism, ready for export to hostile environments. He begins from the relativist premise that it is nearly impossible to appeal from any culture’s beliefs to a more universal or objective standard of morality. As he writes in “Objectivity and Social Meaning,” criticism of any society “is not objectively true or false, for it also depends on an interpretation of social meaning.” That is, a society can only be justly criticized from within its own premises, not from the alien premises of an outsider. The only exception he seems willing to allow, the only genuinely universal moral law, is what he calls, in the essay “Nation and Universe,” the “rights of reiteration.” That is Mr. Walzer’s name for the right of human beings in any society to invent anew their own particular standard of good and evil, free from the interference of outsiders, however well-meaning. “Immorality,” he writes, “is commonly expressed in a refusal to recognize in others the moral agency and the creative powers that we claim for ourselves.”

This sounds like a thoroughly neutral, value-free principle. But in fact, it is not hard to see that Mr. Walzer’s desire to honor “moral agency” has a very specific philosophical provenance: It is a version of Kantian autonomy, a quintessentially modern and liberal notion. It is only because he is deeply wedded to liberalism that Mr. Walzer assumes that all cultures can converge on the liberal belief that the self-legislating individual is the ultimate ground of value. Ironically, Mr. Walzer seems to be guilty of the very same error that he chastises in his polemics against John Rawls and the Rawlsians: His ostensibly neutral moral deliberation rests on principles that he smuggles in because he cannot openly declare them. “If each of us walks with his own god, then all of us will sit in peace under our vines and fig trees,” Mr. Walzer writes sanguinely. But the assumption that our god wants us to sit in peace, rather than to convert the heathen, is already a thoroughly liberal assumption, which would find no purchase in, say, fundamentalist Islam.

The alternative to this illusory neutrality would be openly to confess that liberalism is a positive creed, which holds some human types and some forms of society to be better than others. Such an admission would considerably ease Mr. Walzer’s difficulties in articulating a criticism of the enslavement of women — a practice he clearly loathes but finds it hard, given his axioms, to directly condemn. Nor does it follow, as Mr. Walzer appears to fear in his essays on humanitarian intervention, that such liberal confidence would give rise to liberal imperialism, an attempt to spread Western values by the sword. For liberal values are not essentially Western; they are human, and they will emerge whenever they are given the chance to do so. “I am a little dubious about the global reach of moral commitments that grow up within, and seem dependent on the solidarity of, a particular political community,” Mr. Walzer says in the interview that concludes “Thinking Politically.” Yet even he can’t resist adding: “One day, maybe….”

akirsch@nysun.com