Benny Lévy, who died on Wednesday aged 58, was a prominent Marxist firebrand in the 1968 student protests in Paris, when he was known as Pierre Victor; he became secretary to the philosopher Jean-Paul Sartre, but later embraced orthodox Judaism.
Lévy began working for Sartre in 1974. A month before Sartre's death in 1980, the French magazine Le Nouvel Observateur published a series of interviews between the blind and debilitated philosopher and Lévy which seemed to show that Sartre had abandoned existentialism and Marxist Utopianism and embraced religion in the form of messianic Judaism: "The Jew lives," Sartre proclaimed. "He has a destiny. The finality towards which every Jew moves is to reunite humanity . . . It is the end that only the Jewish people [know] . . . It is the beginning of the existence of men for each other."
French Left-wing intellectuals responded furiously, denouncing the interviews as distorted, inauthentic, even fraudulent. They seemed to portray a Sartre who had abandoned his convictions and rejected his most intimate friends, even Simone de Beauvoir. Lévy was accused of exploiting Sartre's failing health for his own ends.
Yet, shortly before his death, Sartre confirmed the authenticity of the interviews, leaving Sartre scholars with a conundrum which has yet to be satisfactorily explained.
Benny Lévy was born in Cairo, Egypt, on August 28 1945, into a Jewish family. His great-grandfather, Rabbi Yehuda Halevy, had been head of the Jewish community at Jaffa in the mid-19th century.
Lévy moved with his family to Paris at the age of 11 after the Suez crisis and studied Philosophy at the École Normale Supérieure under Louis Althusser and Jacques Derrida. In the spirit of the times, he became a Maoist and one who demonstrated a talent for firebrand oratory.
When radical French students threatened to bring down the government of General de Gaulle in May 1968, Lévy, under the pseudonym Pierre Victor, became leader of one of the most militant student groups, La Gauche Prolétarienne. It was he who negotiated between the students and striking workers.
After de Gaulle resigned in 1969, Lévy attempted to keep the revolution alive as an editor of the Left-wing newspaper La Cause du Peuple. He and his editorial colleagues were often detained by the French police. In 1970, as the arrests became more frequent and the newspaper was threatened with closure, the editors appealed to Jean-Paul Sartre, regarded as the "Voltaire" of the Left - the one French Leftist the authorities dared not touch. Sartre agreed to add his name to the editors' list and afterwards the police left them alone. In 1972, Lévy was instrumental in the launch of the Left-wing daily Libération.
As Lévy and Sartre grew closer, Sartre invited him to become his personal secretary. Together they studied works about the French Revolution. This took them by degrees to the English civil war and Lévy was struck by the Biblical language used to justify opposing the King. Going back even further, they studied Gnostics, Manicheans and other heretical and "revolutionary" sects. Then they found the Torah.
"I became a Jew against my will," Lévy recalled, "out of intellectual necessity. And I was a Jew who so wanted to assimilate. My mission in life was to be France's greatest intellectual Goy. Sartre sobered me up. I saw the intellectual world in all its ugliness - not Sartre, whose beauty I had the good fortune to see - but the intellectual swamp all around."
Quite who influenced whom was not entirely clear. The Palestinian scholar Edward Said recalled meeting the pair in 1979 at a conference, co-chaired by Sartre in Paris, to discuss Arab-Israeli relations.
Lévy (then still known as Pierre Victor) seemed to Said to be: "a sort of station master, among whose trains was Sartre himself. Aside from their mysterious interactions at the table, he and Victor would occasionally get up; Victor would lead the shuffling old man away, speak rapidly at him, get an intermittent nod or two, then the pair would come back." When Sartre made a platitudinous closing statement that failed to mention such burning issues as the Palestinians, disputed territories or Israeli settlements, Said assumed it had been written by "the egregious Victor" himself.
By this time, Lévy had "finished" with the proletarian revolution and had begun to study the works of the French Jewish thinker Emmanuel Levinas, one of the leading ethical philosophers of post-Holocaust Judaism. Inspired by Levinas's commentaries on Talmudic texts, Lévy began to learn Hebrew, took religious instruction and began attending the synagogue.
In the 1990s, Lévy moved to Israel and devoted himself to Jewish religious texts. "I lost my political dreams and my political view of the world," he said in 2000. "I thought I would die. I was empty, totally empty. But the Torah has come to refresh my soul like life-giving water. I have found in it all the metaphysical depth I was seeking."
In 2000, together with the philosophers Bernard-Henri Levy and Alain Finkielkraut, Lévy opened an institute in Jerusalem dedicated to the study of the work of Emmanuel Levinas.
Lévy's latest book, To Be Jewish, is to be published next month.