BOOK REVIEW / The gaol keeper's fear of the penalty: Michel Foucault - Didier Eribon, Tr. Betsy Wing: Faber, pounds 25

THERE ARE plenty of good reasons to loathe contemporary French philosophy: Derrida's a prima donna, Baudrillard's putting us all on, Irigaray may actually be a little nuts, and both Althusser and Barthes have been run over by large motorised vehicles. The deconstructionists, meanwhile, continue to unwind recklessly tone-deaf sentences in order to refute their ability to communicate anything; the proto-Marxists deify the working class in a prose style that no upstanding member of the working class would be caught dead reading; and the feminists freely lift their terminology from practically everybody - Lacan, Marx, Freud - in order to glamorise their collective ability to speak the unspeakable. Confused? You should be. Too often, that's the point.

But while it's easy to get snow-blind reading most of this stuff, the work of Michel Foucault deserves special attention. That doesn't mean it's going to be easy, though: Foucault is a brilliant, convoluted literary stylist, but what he means is never readily apparent, perhaps because his philosophy challenges the very notion of 'meaning' itself.

For Foucault, 'discourse' is not a means of communicating information, but a strategy for deploying power. In his first major work, Madness and Civilisation, Foucault tries to comprehend how and why madness develops as a category of human knowledge in the 17th century. He does not want to analyse or define what madness is, but rather why madness is defined in the way that it is, and to what purposes. Foucault concludes that by identifying something called 'madness', culture can describe the limits of sane behavior; these limits are then disseminated throughout society as scientific knowledge. By learning (and sometimes even contributing) to this knowledge of what is 'normal', people help establish the rules of who they are and how they should behave. Power is not simply force, repression, or imprisonment; it is a system of knowledge to which we all submit. This system is what Foucault often refers to as the 'infrastructure of power'.

In other words, knowledge is never simply factual or disinterested; it is always used to enforce prevailing systems of politics and commerce. To put this in a nutshell: Foucault sees all 'human sciences' as an extraordinarily complex attempt to define the limits of the 'human' (in terms of sanity, health, knowledge, sexuality and so on). In more popular terms, this process might be called 'normalisation', and if you've ever seen photos of middle-America in the Fifties, you know what a frightening process this can be.

According to Foucault, we are all mired in the same oozy confluence of language, or what he refers to as 'power-knowledge,' a system of ideas, sciences, stories, theories and definitions which limit the possible horizons of human expression and endeavour. As far as Foucault is concerned, 'individuality' is a term which is always used to prevent people from becoming, well, individual. He distrusts terms like 'humanity' and 'mankind', since they don't explain who people are but who they should be.

This goes some way towards explaining why Foucault's work is difficult, and why he avoids speaking in a 'normal' human voice. But his writing is also brilliant - charged with complications, contrasts and endlessly unravelling subordinate clauses. Foucault was heavily influenced by Marx, Hegel, and the French Annales school of social historians, but he was never comfortable with any of them. Instead, he went back to Nietzsche and adopted his 'genealogical' method, tracing the relationship between ideas and culture through the generations; he doesn't want to define what goodness is, for instance, but how it has been deployed. Truth is never permanent or ideal, Foucault argues: it is always determined by who uses it, and why. In order to learn, one should not construct edifices of knowledge, but take them apart. Sometimes, like Nietzsche, you use a hammer.

In his greatest work, Discipline and Punish, Foucault explores the ways in which modern systems of discipline do not simply surround people with walls, but invest them with knowledge. This knowledge instructs people how to dress, dance, eat, brush their teeth, hold their tea-cup and kiss their children; it prescribes normal ranges of fashion, architecture, sexual behaviour and personal grooming. It can even be used to define acceptable ranges of the abnormal - avant-garde movements, say, in fashion, poetry or art. Discipline and Punish is one of the modern world's few essential books. It shows that if we want to understand how power operates, we must first question the deepest assumptions we have about ourselves. Like all great books, it confuses us about what we have always believed, and helps us understand what we've never known.

Because the individual is such a treacherous notion in Foucault's philosophy, any biographer faces some pretty severe theoretical problems. Didier Eribon has confronted most of these problems head-on, and has tried to steer something of a middle course. He has chosen to write a concise, respectful, intelligent account of Foucault's intellectual life and development, while paying little attention to the human roar and muddle of how he lived when he wasn't busy thinking.

As a result, Eribon rarely dwells on the intimate, messy details - Foucault's hatred for his father, or the early years of frantic, near-suicidal despair about his homosexuality, or his personal relationships with lovers and colleagues. Instead Eribon focuses almost entirely on Foucault's intellectual life - his academic achievements, political activism, theoretical debts and allegiances.

You can't help but feel a little cheated whenever Eribon attributes a change in Foucault's personal life to philosophical differences - his sudden break with a long-time friend and colleague, Gilles Deleuze, in the mid-Seventies, or with his notorious friend and pupil Jacques Derrida a few years earlier. Eribon rarely considers human motives such as love, anger, pettiness, grief, dishonesty or sexual jealousy to have had profound effects on Foucault's life or philosophy.

Eribon's biography is good and useful work, especially in its depiction of France's fragmenting intellectual left during the late Sixties and early Seventies, but it seems a bit too supportive of Foucault's basic tenets to provide any critical muscle. It is also too respectful of his privacies to make any 'human' sense of his life (which is obviously how Foucault himself would have wanted it).

Foucault resolved many of his personal contradictions by dismissing the importance of the personal in his work. He described systems of sexual and political conformity, but never spoke frankly about what he considered abnormal or embarrassing in himself. He supposedly had a great sense of humour, yet he wrote thousands of dense, utterly serious pages without a laugh. He complained about how institutions ruled contemporary culture, yet he was a devoted academician, and even involved himself in some of the reactionary educational reforms which led to the protests of May 1968. He called himself a structuralist until structuralism became the vogue, and then he said he wasn't one, really.

Eribon's biography of Foucault will be of interest to Foucault's admirers, but it is not the place to start if you're interested in testing the frothy waters of Foucault's philosophy. If you want to learn how he thinks, you might try the essays and interviews collected in The Foucault Reader, which contains an excellent introductory essay by Paul Rabinow.

But if you want to understand how Foucault lived, and why he thought the way he did, you'll have to wait for a book that hasn't been written yet.