Why write a book about Bernard-Henri Lévy? He has not created a theory, not thought of a single original concept, not succeeded in becoming a writer or a film-maker, or even a serious journalist.
And this is the paradox of France's best-known "media intellectual": perhaps it is because he has none of these abilities (to think like a philosopher, write like a novelist or describe like a reporter) that he's become what he is today.
In 1968, Lévy attended the Ecole Normale Supérieure, following in the footsteps of so many of the brilliant figures who have formed the French literary and philosophical elite (notably Sartre, Foucault and Derrida).
Although he qualified to teach in 1971, he did so for only a short time (at a lycée and at Strasbourg University) and never carried out any research.
Lévy quickly escaped academe to try his hand at journalism and editing. He appeared on the French public stage in 1977 on the publication of his second book, Barbarism with a Human Face .
He presented himself as the leading light of the "new philosophers" and attempted to promote an "anti-communism of the Left" in the media and the public domain.
The book was in the vein of Solzhenitsyn and other great writers who had analysed the phenomenon of totalitarianism. Despite containing virtually no new ideas, it seduced all those who having struggled through theoretical texts at school suddenly felt intelligent and able to understand philosophy.
French journalists were impatient to communicate their enthusiasm to the general public. Philosophy, in the form of easy-to-understand booklets that could be read quickly, entered the nation's sitting rooms.
After the phenomenon of totalitarianism, Lévy turned to monotheism, then to the history of France. These three works, which were all commercially successful, make up what one may call "Lévy's thinking". But does it constitute philosophy?
Philosophers and other academics hold few illusions about Lévy's work.
Respected intellectuals who were initially sympathetic towards him, warned him about his lack of rigour, ignorance about established philosophical facts that contradicted his theses and against making vague generalisations.
But Lévy appeared more worried about his media profile than the rightness of his thinking. He dedicated himself to an all-consuming passion: the sculpting of his own image, the forging of his own destiny. He became a "product": an image (his famous white shirt) associated with a logo (BHL) disseminating a simple message (liberty). Ever since, he has been "selling" the BHL product to the public.
In so doing, his interventions have impoverished and simplified intellectual debate for more than 20 years. Whether discussing fascism, Bosnia, the civil war in Algeria or terrorism, his discourse invariably consists of defining goodies and baddies.
Lévy initiated the transformation of the book into a "book event" and then simply into an event. As for his impact in the media, the discussion and argument generated by a book have become more important than the content of the book itself.
Thus, just before my biography of Lévy reached the shops, he accepted an invitation to "react" to it in the weekly newspaper L'Express on January 9 - attacking my work after reading only a ten-page extract.
In fact, he has built a formidable network of allies in the French media.
For example, his book on Wall Street Journal reporter Daniel Pearl was met with dozens of eulogistic articles, while radio and television shows confirmed his eminence, as if French criticism were dead.
It is an essential task of French intellectual life to put an end to this pernicious regime of self-censorship that allows a pretender to be seemingly anointed for eternity.
Philippe Cohen, Journalist for the French weekly newspaper Marianne and author of BHL - A Biography (Fayard, £15.00), published this week