The New Left is rather old news. Hence the title change for this new version of Roger Scruton’s critique of rampant intellectual socialism, which was originally published in 1985 as simply Thinkers of the New Left. Since then, RD Laing and Rudolf Bahro are out; Jacques Lacan, Gilles Deleuze, Edward Said, Alain Badiou and Slavoj Žižek are in. Scruton is brilliant at the patient demolition, in sorrowful yet witty tones, of wobbly conceptual edifices. Yet the zingier, more knockabout new title promises more fury than the book supplies. The only outright “fool” here, in Scruton’s view, is the psychoanalyst Lacan; and only the Austro-Hungarian Marxist critic György Lukács is judged downright wicked. The rest, Scruton diagnoses mainly as wrong though very clever, or wrong and not very clever, or just shatteringly boring.

It is an art to condemn at length the boringness of a thinker without becoming boring oneself, and Scruton perhaps doesn’t quite manage it in his discussion of Jürgen Habermas, the German intellectual and relentless theorist of the “public sphere”. (Scruton does allow, archly, that “interesting ideas surface in the great waste-paper basket of Habermas’s prose”.) Another chapter deals with the “nonsense machine” allegedly constructed in Paris by the poststructuralist gang of Louis Althusser, Lacan and Deleuze. Scruton thinks Lacan and Deleuze were both frauds, and that the latter’s popularity has helped reduce the landscape of the modern humanities to “the intellectual equivalent of the aftermath of the Somme” (Really?). So there is not much to chew on, after Scruton has deftly sketched the historical context and produced this amazing image: “The monsters of unmeaning that loom in this prose attract our attention because they are built from forgotten theories, forged together in weird and ghoulish shapes, like gargoyles made from the debris of a battlefield.”

That is quite something, and of a piece with other gleefully dark put-downs elsewhere (“a morose prowling of the intellect around an inexplicable shrine”). But the problem in general with denouncing people as frauds and charlatans is that you might be paying them too much intellectual credit, and so too little moral credit. Perhaps they really believed this stuff, in which case they were idiots but not dishonest. This book is at its best, by contrast, when Scruton is engaging with writers whom he evidently respects, however much he disagrees with them.

So the historians Eric Hobsbawm and EP Thompson are praised for “the brilliance of their writing” but marked down for their determination to use “historical understanding as an instrument of social policy” (Though who doesn’t?). The legal theorising of the “brilliant” Ronald Dworkin sees Scruton arguing that it contains a “special pleading for judicial activism, provided that the activists are political liberals”. Jean‑Paul Sartre is celebrated for his writing on freedom and sex before his later political interventions are lamented. Of Michel Foucault, Scruton writes alluringly: “the synthesising poetry of his style rises above the murky sludge of leftwing writing like an eagle over mud-flats”. His work is marred by “a great suspicion”, but Scruton finds intellectual redemption in Foucault’s last books, on sexuality. Occasionally, though, one does get the sense that the book hasn’t been updated thoroughly enough, as when Scruton refers to “a consensus of moral conviction against pornography”. There might have been such a consensus in 1985; there certainly isn’t now.

Perhaps as a result of intellectual Stockholm syndrome, Scruton occasionally adopts just that abusive and paranoid style he decries in his opponents. In early communism, he observes, “labels were required that would stigmatise the enemies within and justify their expulsion: they were revisionists, deviationists, infantile leftists, utopian socialists”. Just so, Scruton stigmatises his own enemies in the language of mental illness: Žižek emits “mad incantations”; Althusser’s writing is “like a lunatic trapped in an imaginary cage” (to be fair, Althusser did murder his wife). Lacan, meanwhile, was not merely a charlatan but, it says here, “a crazy charlatan”.

And paranoid? Well, there is apparently a vast left-wing conspiracy to silence conservative voices. He suggests that one arm of this conspiracy is that multimillion-selling propaganda sheet, the New York Review of Books. This, even though Bloomsbury is publishing Scruton’s book with quite a fanfare, and he has received respectful notices over the years in this very paper. Other high-profile rightwingers – say, Niall Ferguson – don’t seem to have much trouble getting work these days either.

Jean-Paul Sartre, initially lauded by Scruton but later lamented. Photograph: Corbis

Scruton indulges in a paranoid style of reading, too. Hurrying on from Deleuze’s respected works on Spinoza and Kant, he decides to locate “the true nature of his thinking” elsewhere. Similar treatment is accorded Žižek. Scruton introduces this impish superstar of the philosophical commentariat with a purr of approval: Žižek is “seriously educated”, he “writes perceptively of art, literature, cinema and music”, and “he always has something interesting and challenging to say” about current events. And yet in the next paragraph, Žižek is a global “nuisance”. So where must we look for his intellectual sin? Why, in “the true content of his message”: in “his little pellets of poison”, such as Žižek’s notorious claim that Hitler was “not violent enough”.

All quotation is selective and all quotation is out of context — still, you cannot really get away with quoting such a deliberately provocative formulation of Žižek’s without saying what he means. Žižek is arguing that it would have been better had Hitler engaged in a thoroughgoing remaking of social and political institutions, rather than a programme of industrialised mass murder. By refusing to explain this, Scruton disingenuously invites the reader to suppose that Žižek thinks Hitler ought to have killed more people.

Just like his communist-minded opponents, then, Scruton seems to think exclusively in terms of an embattled “us” versus a homogenous “them”. The overall effect is quite gloomy. Sadly not countenanced within these pages is the possibility that a person might not care for Lacan or Deleuze but still admire Sartre, Jacques Derrida and Žižek — and, for that matter, Scruton.

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