This incident, which came to be known as the Busenaktion ("breast action"), has never figured with much prominence in American studies of the Frankfurt School. Americans are far more apt to think of the leading figures of Critical Theory–Adorno, Max Horkheimer, Herbert Marcuse, and others–languishing in exile in New York and southern California during the Nazi period, or of the eclectic blend of Marxism, psychoanalysis, and sociology that characterized their thought. Their work is famous for its mandarinism, its abstraction, and–especially in the case of Adorno–its uncompromising commitment to the independence of critical thought and high art. Yet in Germany, on the thirtieth anniversary of the student revolts of 1968, the Frankfurt School is also remembered for its vexed role in the volatile, sometimes violent political upheavals of the 1960s.

The Busenaktion was just one of many confrontations between the increasingly "praxis"-oriented German New Left and the theoreticians who had been its mentors. The turbulent evolution of this relationship is the subject of Wolfgang Kraushaar’s elaborate three-volume work, Frankfurter Schule und Studentenbewegung: Von der Flaschenpost zum Molotowcocktail, 1946—1995 (The Frankfurt School and the Student Movement: From the Message in the Bottle to the Molotov Cocktail, 1946—1995), published in Germany this past spring by Rogner & Bernhard. A political scientist at Hamburg’s Institute of Social Research and a bona fide ’68er, Kraushaar has produced a painstaking and lavish collection. It consists of a meticulously detailed historical overview, an extensive compendium of documents and photographs, and a collection of retrospective essays with titles like "Dialogues on Theory and Praxis" and "The Oedipal Complex of the ’68ers."

The story that these volumes tell ends on a sorry note. Adorno and Horkheimer, the grand old men of the German intellectual left, saw their lectures heckled, their institute occupied, and their own students, notably Adorno’s protégé Hans-Jürgen Krahl, turn against them. In a moment of despair during the student occupation of the institute in January 1969, Adorno called the police. Students were outraged at his betrayal. "Adorno as institution is dead," declared a flyer distributed by a radical group of sociology students in April of that year.

Adorno himself would survive just another few months. He died of a heart attack in Switzerland on August 6, 1969, at the age of sixty-five. Six weeks earlier, he had written to Marcuse of his "extreme depression" and of his revulsion at the fascist overtones he sensed in the tactics and demands of the students.

Yet relations between leftist German students and their mentors had not always been so antagonistic. Kraushaar begins in the late 1940s, when Horkheimer and Adorno, the two central figures from the prewar incarnation of the Frankfurt-based Institut für Sozialforschung, returned to Germany from their American exile. Their "critical sociology," which fused the insights of Weber with those of Marx and Hegel, along with their trenchant critique of fascism, attracted students looking for alternatives to the positivism and conservatism that dominated German intellectual life.

When Horkheimer first returned to Germany, originally as a guest professor at the University of Frankfurt in 1948 and then as the chair of sociology and philosophy in 1949, his students received him warmly. From the outset, he and Adorno assumed the role of spokesmen for "the reeducation of German youth." Because they were left-wing intellectuals and returned Jewish refugees who had been personally affected by the horrors of National Socialism, the two were less suspect to radical students than instructors who had remained in Germany under Hitler. Both found that German students took to their ideas, and both recognized promising signs of intellectual advancement among their disciples. "They are learning to express themselves and to have the freedom to say what they believe," announced Horkheimer in a Frankfurt-based student newspaper in 1960. Several of their early students and associates, Jürgen Habermas among them, would go on to become leading intellectuals.

As the political climate shifted in the mid-1960s, however, the very students who had been vocal and independent just a few years earlier became disenchanted with the Olympian detachment of their mentors. In 1964, under the charismatic leadership of Rudi Dutschke, the radical organization Subversive Aktion undertook a series of confrontations with the elder spiritual leaders. Dutschke was also largely responsible for the spread of anti-Establishment activism within the growing Sozialistischer Deutscher Studentenbund (Union of German Socialist Students, or SDS), which demanded the total transformation of German society. His group challenged the conservatism of the Adenauer administration and declared that the denazification of West German society and its institutions had been halfhearted and ineffectual. The rise of the civil rights and anti-Vietnam movements on the other side of the Atlantic further inspired the radicalism of these students. In a 1967 debate, Dutschke dismissed Habermas’s thought as outdated; Habermas responded by calling Dutschke’s unbridled activism "left-wing fascism."

At the same time that Adorno was working on such rarefied theoretical works as Negative Dialectics (1966) and Aesthetic Theory (1970), the SDS was operating under the banner "Enlightenment through Action," and engaging in demonstrations: against the Vietnam War, against repressive university reforms, and against the right-wing German media monopoly. The elder professors were not amused. Like such American Old Guard leftists as Irving Howe, who expressed distaste for Tom Hayden and the American Students for a Democratic Society, the Frankfurt School veterans were disturbed by the youthful disrespect of liberal institutions and disgusted by what they saw as a dogmatic faith in the primacy of action. "I established a theoretical model of thought," Adorno remarked. "How could I have suspected that people would want to implement it with Molotov cocktails?"

But members of the student movement did not abandon the work of their elders altogether. They circulated pirated copies of Dialectic of Enlightenment (1947); they rediscovered Georg Lukács and the Marxist texts of Walter Benjamin; and above all they turned their attention to the writings of Marcuse. His One-Dimensional Man (1964), already influential in America, appeared in German translation in 1967. The year before, Marcuse, who had remained in American exile, visited Germany. At the University of Frankfurt, he gave the keynote lecture at a student-sponsored conference on Vietnam, an event at which more than two thousand students were present and which led to mass antiwar demonstrations. Already known for his support of the American student movement, and for his mentorship of Angela Davis, Marcuse drew instant sympathy from the German students and formed a lasting friendship with Dutschke. In his celebrated essay "Repressive Tolerance" (published in German in 1966), Marcuse declared that in the case of insurrections among the oppressed, "no third party, and least of all the educator and intellectual, has the right to preach them abstention."

Unsurprisingly, Horkheimer and Adorno were suspicious of Marcuse’s engagement with the student rebels. A firm believer that science (Wissenschaft) and culture (Kultur) should be autonomous spheres, free of any direct involvement with politics, Adorno declared that he would remain a "theoretical human being," unwilling to draw practical consequences from his ideas. "If I were to give practical advice in the way that Herbert Marcuse has to a certain extent done," Adorno remarked in a 1969 interview in Der Spiegel, "it would be at the cost of my own productivity."

Although the students vilified him for such quietism, Adorno’s view of them was more ambivalent. On his deathbed he dictated a final letter to Marcuse, hoping to prevent the gulf between them from growing any wider. His words struck a remarkably conciliatory note: "I am the last to underestimate the merits of the student movement," he insisted. "It has disrupted the smooth transition to a totally administered world"–the world whose coming his own work so passionately decried.

In 1959, in his lecture "What Does Coming to Terms With the Past Mean?"–a key text for Germany’s postwar confrontations with its National Socialist legacy–Adorno had argued that the most urgent task facing postwar Germany was the eradication of those aspects of German culture and society that had enabled fascism to take root. In a different way, the German ‘68ers saw themselves as carrying out that very task. Of course, the wounds of the past, inflamed by the rise of terrorism (led by guerrilla groups like the Red Army Faction), in the 1970s, may not yet be healed. But now, thanks to Kraushaar, participants in this generational conflict can begin to come to terms with their own past.