Join in the fight while leaning on lamppost

To Richard Posner, a prominent US judge, the willingness of intellectuals to offer "real-time commentaries", for instance on the events of September 11, is a symptom of the deplorably low level of contemporary public debate. In Public Intellectuals: A Study of Decline he attempts to diagnose the cause of this state of affairs. Posner lays the blame at the door of the modern university, specifically the legion of over-educated and under-experienced academic superstars who "opine" (his favoured term) to a non-specialist, educated public - the readership courted by Public Intellectuals - on issues beyond their professional expertise.

Part one sees Posner in the guise of social scientist, furnishing a statistical analysis of the "public intellectual market". His taxonomies of diverse, intellectual figures, however, trample over distinctions that academic specialists hold dear. Bizarrely, he compiles a top 100 of American public intellectuals on the basis of media mentions. Few apologists for the informing values of intellectual life will be pleased to see Henry Kissinger head the list - and Posner charts at 70, below Camille Paglia, but above Aleksandr Solzhenitsyn. It is hard not to protest at the crude methodology of his bibliographical tables, or simply to wonder what precisely one learns about the decline of current American intellectual discussion to read that C. S. Lewis received 2,891 media hits. Using statistics as a drunken man uses lampposts - for support rather than for illumination - Posner claims to chart the eclipse of the "independent" public moralist (such as Orwell) by the comfortably tenured academic.

Part two sees Posner in the guise of jack-of-all-trades, ranging across literature, philosophy and politics in chapters that display wide reading but superficial understanding. At no point in a tour de force of brisk judgements on western writers does Posner pause to examine the language of literature. The nearest he comes is a simplistic endorsement of Orwell's attack on Auden's use of the phrase "necessary murder" in Spain ; a devastating critique, he suggests, of the dangers of a "sheltered, academic life". Is the moral of Posner's ethics of engagement that Old Etonians should skip university and fight alongside the anarchists if they aspire to speak publicly on political issues, or even with "great moral authority about political murder", to quote his odd and misleading praise of Orwell?

Posner's Orwell is a closer relation to Richard Rorty's exemplary liberal intellectual in Contingency, Irony, and Solidarity than the real-life Eric Blair and, with a neat circularity, Rorty is hailed as "our Orwell". However, Rorty's proposed leftist social reforms are loftily dismissed as "unworldly". Ridicule of the excesses of Robert Bork and the American right does not disguise Posner's own conservative response to social change. A political pragmatist with legal training, he is properly sceptical of claims to intellectual disinterestedness. All the same, Posner's account of his "nasty little spat" with Ronald Dworkin during the Clinton impeachment imbroglio hardly reassures us that the courtroom offers the sort of policing he feels is deficient in the public intellectual sphere.

Public Intellectuals is an insufficiently thoughtful book. It is also a missed opportunity, for Posner assembles some provocative evidence to question the public role of the intellectual. Given the ingrained anti-intellectualism of American society, the dangers of media distortion and vulgarisation, it is less surprising that public debate is often done badly, than that it thrives. Neither do self-serving or wrong-headed analytical predictions by academic intellectuals obviate a laudable freedom - enshrined in the American Constitution - to influence public opinion. Predictive success is, at any rate, a poor way to judge a self-styled oppositional intellectual such as Edward Said. Posner's closing plea for greater openness and accountability when academics intervene in public affairs might, incidentally, have enabled some readers to better appraise Said's controversial reflections post September 11, had it been made clear that Said was speaking on behalf of secular Arabs. Regrettably, Public Intellectuals has little to say about the frustrations and alienation that fuel discontent in the realms where intellectual discourse breaks down.

Jason Harding is assistant director, department of foreign languages and literature, Feng Chia University, Taiwan.