It was a heady moment. Liberation was at hand. The world's most powerful totalitarian state had been defeated. World-historical struggles had come to an end.

Such was the situation after the Soviet Union collapsed. And the sense of triumph was palpable. In an essay reprinted in "The Norman Podhoretz Reader" (Free Press), Mr. Podhoretz wrote a "Eulogy" for neo-conservatism — the political and cultural movement with which he and the magazine he edited, Commentary, had been so closely identified. It was a eulogy that proclaimed satisfaction and closure. For two decades, Commentary had advocated unrelenting challenges to Soviet power, and while the downfall had never been seen as imminent, it had always been hoped for.

In his introduction to this new collection — which samples Mr. Podhoretz's argumentative power and rhetorical range over nearly 50 years — Paul Johnson notes that the Soviet collapse also brought to its end an era in American intellectual life in which Mr. Podhoretz had been a major player.

But as central as Soviet Communism was to neo-conservativism, the eulogy, of course, was premature. History did not come to end. Free-market economies ran into trouble. Genocidal massacres took place. Terrorism erupted. Old conflicts were metastasizing, emerging in new configurations. So neo-conservativism continues, now even taking center stage, named as the ideology behind President Bush's foreign policy.

In neo-conservatism's continued evolution, though, how are lessons learned from the past to be applied to a transformed world? An example from the past may show how vexed such questions can be.

Consider the period just after the Second World War, when another tyranny had just collapsed. It seemed as if the Allies had, through their trials, learned something about totalitarianism and democracy. Could those concepts be used to understand the Soviet Union, the West's erstwhile partner? Was it something very different (a humanitarian revolutionary state gone awry) or something very similar (a fascistic state beyond saving)?

Such issues affected the impassioned arguments between the two most important writers in postwar France, Albert Camus and Jean-Paul Sartre. In his new book, "Camus and Sartre: The Story of a Friendship and the Quarrel That Ended It" (University of Chicago), Ronald Aronson, who teaches at Wayne State University, traces the nuances of their friendship, their mutual influences and hostilities, and the themes that still haunt contemporary debates.

Their schism over Communism was not academic. At the time of France's liberation, buoyed by its Resistance role, the Communist Party had 400,000 members; that figure almost doubled by 1946, and the party joined a coalition government. In addition, according to Mr. Aronson, the party dominated the largest trade union, published dozens of newspapers including the country's two largest, and had a payroll of more than 14,000. The Communist Party was part of the mainstream in a way it never was in the United States.

But its allegiances were just as open to question: it slavishly followed Soviet leadership; fellow travelers idealized the Soviet Union, despite readily available accounts of horrors. André Gide, who visited Russia in the 1930's, said he doubted whether anywhere, even in Hitler's Germany, the "mind and spirit are less free, more bowed down."

Camus had joined the party in Algeria in 1935 and left two years later in dismay. Mr. Aronson even implies that Camus' views on absurdity and freedom grew out of that experience.

Then, in France, during the German occupation, Camus did heroic work as editor of a Resistance newspaper, Combat. Sartre, in their developing friendship, called Camus an "outstanding example" of a life lived in "engagement." After the war, both men saw an opportunity to remake the world, redressing social ills. Both also wanted to steer the French left away from the Communists while distancing themselves from the growing cold war.

But by 1948, Sartre had become a fellow traveler, even giving the party the right to censor one of his plays. He called freedom under capitalism a "hoax" and France a "society of oppression." He refused to denounce Soviet labor camps or the show trials. And he justified revolutionary violence, praising the African revolutionary Franz Fanon.

Meanwhile, Camus found himself ever more repulsed by Communism, which he called "the modern madness." He saw Communism as a desperate attempt to create meaning and certainty. He wrote, "Those who pretend to know everything and settle everything finish by killing everything." If there were a choice between justice and freedom, meaning a choice between the ideal Communist state and the flawed Western state, he wrote: "I choose freedom. For even if justice is not realized, freedom maintains the power of protest against injustice and keeps communication open."

After Sartre's journal, Les Temps Modernes, panned Camus's influential counter-revolutionary book "The Rebel" in 1952, the friends never spoke again. Sartre's influence was so strong that Camus' French reputation was not repaired even after winning the Nobel Prize in 1957. But Mr. Aronson does not want the reader taking sides. He insists that we have to "free ourselves from the dualistic thinking of the cold war," and not take the "currently fashionable" view praising Camus.

Mr. Aronson argues, in fact, that "like many another anti-Communist, Camus wrecked his own moral and political coherence by avoiding talking about his own society" while Sartre correctly "confronted the violence of the democratic capitalist system" and the evils of colonialism. But in this, Mr. Aronson is simply taking Sartre's side without attending to its minefields.

Camus, in his concreteness and human sensitivities, is more perceptive, and in his compassion, more trustworthy. He had a major influence on later French writers like André Glucksmann, Bernard-Henri Lévy and Pascal Bruckner — the neo-cons of the French left. And in Camus's rejection of utopianism and his acceptance of sad compromise there remain hints of what might form some sort of realistic political ideal.

Copyright 2004 The New York Times Company. Reprinted from The New York Times, Arts & Ideas, of Saturday, February 7, 2004.