Philosopher With No Face : MICHEL FOUCAULT, <i> By Didier Eribon, translated by Betsy Wing (Harvard University Press: $27.95; 374 pp., illustrated)</i>

When Michel Foucault was hit by a car in front of his Paris home in July of 1978, he asked that someone contact his friend Simone Signoret; he had the text of a political petition to deliver to her. The policeman who phoned the actress apologized for interrupting her. She responded: “You don’t know who he is? He’s the greatest French philosopher!� This minor accident didn’t claim him, though six years later AIDS did. He died at age 58.

In France, he was certainly considered a philosopher, though at his death perhaps not widely considered the “greatest.� Elsewhere, especially in the United States, he was thought to be a great and fertile intellect, but not at all a “philosopher.� American philosophy departments, concerned more with analysis of words than engagement with the world, distinguished themselves by staying away in droves from his lectures at universities in New York, Vermont and California. Historians, anthropologists and literature departments found him scintillating, and, in his last few years, even the public thronged to hear him; Time magazine devoted two ironic pages to his “cult� status and his “opaque� theories.

His own response to the term philosophy was typical: He redefined it. In a 1967 interview, he said, “It seems to me that philosophy no longer exists; not that it has disappeared, but that it has been disseminated into a great number of diverse activities.�

Who was this rapacious thinker, whose books swept across the intellectual terrain like powerful searchlights, whose thinking trespassed sacrosanct academic boundaries with ease? Thin, bald, bespectacled, yet somehow cherubic, he was also something of a dandy. A well-known public figure--politically active, publishing and lecturing often, granting many interviews--he also was an exceedingly private man. In a late preface, he described his books as labyrinths in which he could lose himself, and added, “I am no doubt not the only one who writes in order to have no face. Do not ask who I am and do not ask me to remain the same.� Foucault’s mentor, historian of religions Georges Dumezil, who knew him perhaps better than anyone, called him a man of ever-changing masks, and said that there were “a thousand Foucaults.�

Though he is frequently accorded the intellectual stature of Sartre, he has none of that goggle-eyed thinker’s complete openness about every detail of his public and private life. All this would seem to make a biographer’s task rather daunting, but Didier Eribon, a journalist who knew Foucault for his last five years, has produced an astonishingly readable account of the man and his ideas, which is also in many ways an intellectual history of postwar France, so wide a trail did Foucault blaze in his time.

Eribon has traveled widely, interviewing relatives, friends and colleagues ranging from diplomats and fellow professors to the literary avant-garde. Though presenting basically a chronological reconstruction, he is not overly constrained by dates, and moves backwards and forwards in time to more easily follow and develop recurrent themes and relationships.

We encounter the young Foucault’s refusal to follow in his father’s medical footsteps, the disruptions of a provincial wartime education, with teachers moving or arrested without warning and bombings forcing frequent retreats to shelters. We glimpse the early emergence of his brilliance, especially with languages, but also the torments of an unstable youth who more than once attempted suicide and once was caught in the middle of the night chasing a fellow student with a dagger.

The school doctor who cared for him during this period has said, “These troubles resulted from an extreme difficulty experiencing and accepting his homosexuality,� and indeed, the social definitions of madness and sexuality would be twin themes that occupied Foucault throughout his life.

We follow his peregrinations to Uppsala, Warsaw and Hamburg, in a five-year period of self-imposed exile which Foucault intended to continue indefinitely, living “between two suitcases,� wishing “never again to touch a penholder.� Nonetheless, during this period he completed his doctoral thesis on the history of madness, a work of nearly 1,000 pages, inaugurating a brilliant and groundbreaking series of historical excavations that often focused on what we have tended to label marginal characters or special situations. In our definitions of madness, our practices of punishment, our codification of medical knowledge in the language of the visible, and our tendency to abstract something we call “sexuality� from the lives of individual human beings, Foucault located the little-examined but crucial foundations of the construction of all social experience.

Though he eventually settled in Paris, Foucault’s polymathic intellect could not be confined to one field of knowledge; his mission increasingly became the investigation of the hidden assumptions and connections lying behind our perhaps overly familiar institutions, forms of life and power structures. By regrounding philosophy in the “human sciences� of history, psychology, anthropology and philology, he had a liberating effect on each discipline he considered.

Foucault was a tireless researcher, combing libraries and archives for original texts and long-forgotten documents. By resurrecting these shards of history, he also began calling into question the privileged status we give to so-called “literary� texts.

Philosopher Gilles Deleuze, a contemporary of Foucault’s, has predicted that, in intellectual matters, we will think of this as “a Foucaultian century.� Eribon’s sensitive, lucid and wide-ranging intellectual biography gives us both an appealingly personal view of this quirky and brilliant man, and also a sense of his true stature.