Getting away with murder: It's the talk of Paris - how Louis Althusser killed his wife, how he was an intellectual fraud. It's all in his posthumous autobiographical memoir. Gilbert Adair turns the pages

'Kneeling beside her, poised over her body, I am massaging her neck. I have often massaged her in silence, the nape of her neck, the small of her back: I learned the technique from a fellow prisoner of war, little Clerc, a professional footballer, an expert in everything.

'But this time it's the front of her neck that I'm massaging. I place my two thumbs on the hollow of flesh round the top of the breastbone and, applying pressure, one thumb to the right, the other aslant to the left, I slowly reach the harder zone beneath the ears. I massage in a V. I feel a great muscular fatigue in my forearms; they ache whenever I give a massage.

'Helene's features are serene and motionless, her open eyes gazing up at the ceiling.

'And suddenly I'm terror- stricken: her eyes have glazed over as if for ever and a tiny portion of her tongue is visible, strange and calm, between her lips and her teeth.

'I've seen dead people before, to be sure, but never in my life have I seen the face of a strangled woman. I nevertheless know she's been strangled. But how? I stand up and I cry out, 'I've strangled Helene]' '

That is a passage extracted from the very first page, not of some crude fictional shocker but of an extraordinary, comparison-defying confessional text, currently a huge best-seller in France, read by the sort of people to whom it would never have occurred to open one of its author's books before. L'Avenir dure longtemps ('The Future Lasts a Long Time') is a posthumous autobiographical memoir by the great Marxist philosopher Louis Althusser, the same Althusser who on the morning of 16 November 1980 had staggered out of his apartment in the Ecole Normale Superieure, the fabled nursery of the French intellectual elite, screaming that he had murdered his wife.

Because the crime had been committed in a fit of depression, and perhaps also because of the criminal's eminence - acknowledged even by those institutions of state to which his writings could scarcely have been less congenial - Althusser was spared the ordeal of a public trial. He was interned in various clinics and lived on, ostensibly a hopeless case, forgotten by all but a handful of close friends, until his death in 1990 at the age of 73.

While under psychiatric observation, however, he never ceased writing and actually seems to have been rather more prolific than he was at the height of his fame. At that time, in the Sixties and Seventies, he had come to personify the Socratic ideal of a philosopher without an oeuvre, his two most influential books, Pour Marx and Lire 'Le Capital', being simply collections of his lectures and surprisingly brief. L'Avenir dure longtemps is, in fact, the longest and most substantial of all his published works; and, given the decline of the Marxist ideology of which he was the most prestigious French theorist, the crowning irony of his life is that it is probably the book by which he will be remembered.

Certainly, there has never been anything quite like it. Prompted in part by an article in Le Monde that sardonically compared Althusser to Issei Sagawa, the young Japanese student who became a darling of the media after murdering and eating his Dutch girlfriend, the book can only be read as an act of wilful self-destruction, a unique example of what might be called 'posthumous suicide', both personal and professional. If the emperor is seen to be wearing no clothes, it's because he himself elected to strip naked in public.

In one astonishing passage, which is likely to have destroyed his reputation for ever, Althusser reveals how ill-read he really was: the possessor of thousands of books of which he now claims to have opened only a few hundred. His expertise in philosophy, in the history of ideas, was sketchy at best: 'I knew the work of Descartes and Malebranche well, Spinoza a little, Aristotle not at all; Plato and Pascal quite well, Kant not at all, Hegel a little.' He was not even particularly conversant with Marx, having read only his early works when he came to write his own seminal Marxist texts. What he was blessed (or cursed) with was an infallible knack for extrapolating from commentaries and occasionally from no more than casual conversations those ideas and intuitions that he knew he would be able to exploit and develop in his own writings. He relates how he contrived to impress his first teacher, the Catholic theologian Jean Guitton, with a paper whose guiding principles he had simply filched from Guitton's own corrections of a fellow student's essay, and how he concocted fake quotations in the thesis he wrote for another major contemporary philosopher, Gaston Bachelard.

Althusser appears to have lived out his whole adult life in the terror that his inadequacy as a thinker, his fraudulence (the word he himself uses), would sooner or later be exposed to his colleagues, his disciples and his enemies. It has happened later rather than sooner and only because, for whatever reason, he chose to bring it on himself.

On the private self he is no more merciful. Haunted by the spectral memory of another Louis Althusser, his father's brother whom his mother had initially intended to marry but who was shot down over Verdun, and paradoxically contaminated by his mother's obsessive fixation on bodily purity, he was already in his twenties before he learnt how to masturbate (he describes in some detail a curious genital condition that made erections painful for him) and almost 30 when he had his first sexual encounter - with Helene Rytmann, a Communist militant, whom he was to strangle 30 years later. 'She loved me,' he writes, 'as a mother might love her child, her miraculous child.'

Although he defends her to the end, even hinting that her murder should be regarded as an act of euthanasia, a 'suicide by proxy' (she had often threatened to kill herself), Helene was patently something of a virago and a trial to his colleagues. Theirs was a nightmarish union, violent and practically friendless. He loved her in his fashion but found no peace of mind with her, no respite from his chronic crises of identity. For him, the 'real' Louis Althusser had been killed in the First World War and he spent his life cowering in a network of fortresses to shield himself from a world in which he felt, he knew, he was a fraud. These were, in turn, the Catholic church, the PoW camp in which he sat out the war (and from which, a self-confessed coward, he never attempted to escape), the Communist Party (which he never left, even after Hungary, Czechoslovakia and Afghanistan), the Ecole Normale and, in the aftermath of his crime, the various hospitals of which he seems to have been a rather demanding inmate. The iconoclastic philosopher turns out to have been a man in constant quest of order and

security.

Yet the fascination of the book does not reside solely in the obscene spectacle of its author's nakedness. (The author and journalist Cyril Connolly once said that no one writing completely honestly about himself could fail to produce a masterpiece.) Even in a book as revelatory as this, representing the first time a thinker of such stature has been able, by a terrifying privilege, to write about madness and murder in the first person, there are levels of candour of which, as in any other text, the author himself is not entirely in control.

There is, for example, something a little too calculating about the way it leads off with an exhibitionist description of the crime itself, as if to grab the reader's attention at once (as I myself hoped to do at the beginning of this article). His endless theorising of his relationship with Helene tends to obscure the bare fact that he was after all her murderer and she his victim. And it is somewhat disturbing to find him still defending (in 1985) the Nazi-Soviet pact and the long discredited belief that there can be no salvation for the proletariat outside the Communist Party - in this instance, the notoriously Stalinist French CP.

But there is perhaps a wider lesson to be drawn. Nearly all the great intellectual gurus of the Sixties and Seventies are dead - Sartre, Lacan, Barthes, Foucault and finally Althusser himself. The Eighties duly mourned them and it now seems as if the Nineties have ushered in a period of ghoulish iconoclasm. L'Avenir dure longtemps is only the latest in a series of texts which have had the effect of demystifying the Parisian intelligentsia of the past two decades. There was, most recently, the publication of Simone de Beauvoir's correspondence, which shed a less than flattering light on both Sartre and herself. Francois Weyergans's best-selling novel, Le Pitre, was a cruel debunking portrait of Lacan. Barthes's posthumous Incidents was a melancholy little volume in which he wrote of his loveless frequentation of rent boys. Herve Guibert's A l'ami qui ne m'a pas sauve la vie recounted the violent sex life of his friend Michel Foucault, the first celebrity publicly known to have died of Aids. Julia Kristeva's Les Samouras was a transparent roman-a-clef in which all of the above were shown to have had feet of clay.

Philosophers, pure thinkers, are not really supposed to have faces or bodies. And what all of these thinkers shared was a mistrust of the 'subject', of the author as the privileged creator and interpreter of his own work, of the legitimacy of biographical information as a support to the comprehension of a text. Yet they, too, had lives, and those lives have now returned, with a vengeance, to haunt their work.

(Photographs omitted)