In 1996, the cultural studies journal Social Text carried a paper with the mind-boggling title "Transgressing the Boundaries: Toward a Transformative Hermeneutics of Quantum Gravity". Its author was the physicist Alan Sokal, who had taken on the challenge of assessing the philosophical and political implications of the quest to unify the two cornerstones of modern physics: quantum theory and Einstein's theory of gravity, general relativity.
Cutting across such disparate and complex areas, Sokal's paper was never going to be an easy read - not least because of its references to the notoriously opaque works of postmodernist thinkers such as Jacques Lacan. So we learnt, for example, that Lacan was indeed correct to suspect "an intimate connection between the external structure of the physical world and its inner psychological representation qua knot theory", as this had been confirmed by recent research on "knot invariants (in particular the Jones polynomial) from three-dimensional Chern-Simons quantum field theory".
Most likely the editors of Social Text were delighted to receive so broad-ranging an analysis from a genuine expert in the esoterica of modern physics. They were doubtless much less delighted to discover immediately after they published the paper that they had been victims of a hoax.
For many scientists Sokal became something of a hero in confirming their suspicions of the faux-intellectual nature of social studies - especially when they trespass into the realm of science. Yet Sokal insisted that his target was different, being political in nature. He was seeking to combat "a penchant for subjectivism - which is, I believe, inimical to the values and future of the Left".
What has become known as the Sokal Hoax forms the backdrop to Beyond the Hoax, a collection of Sokal's writings that delves more deeply into the oft-ignored focus of his concerns. Most of these essays first appeared in the late 1990s, but all have been updated, expanded or published for the first time, making them a valuable contribution to the ongoing debate over subjectivism in all its manifestations.
The collection opens with a newly annotated version of what Sokal terms his "parody", which explains the aim and background to each statement - and, in the process, highlights the phenomenal effort required to make it seem authentic. This is followed by a paper rejected by Social Text that explains his motivation and includes the memorable line: "Anyone who believes the laws of physics are mere social conventions is invited to try transgressing those conventions from the windows of my apartment. I live on the twenty-first floor."
Sokal stresses the political underpinning of his concerns, specifically his fear that the Left is vulnerable to "subjectivist and relativist philosophies" that threaten to undermine its critique of the structure of society. If there is no "truth" but merely "claims of truth", how can the Left hope to win the debate over its adversaries? This is the heart of the Sokal Hoax - a revelation likely to surprise those who dismissed it as a stunt by an arrogant physicist.
That said, Sokal is not above giving academics engaged in science studies a good kicking. The collection includes an essay in which he critiques claims that the methods of science are "contaminated" by class and gender prejudices. Sokal presents some choice examples, such as Sandra Harding's argument that Newton's Principia is a "rape manual". As he notes, such bizarre perspectives contain the seeds of their own destruction, as they too can be dismissed as "merely" another socially contaminated viewpoint.
Two essays, co-written with the Belgian physicist Jean Bricmont, address the more serious question of why science has a greater claim to authority than other approaches to understanding reality. Readers expecting a robust defence of the party line - the primacy of Popperian falsification and the attainability of objectively true statements about reality - are again in for surprises. Sokal and Bricmont point out the deficiencies of Popper's tenets, and insist only that science makes progress towards truth, not that it can ever attain it.
Of all the essays, these two promise most and deliver least. Their previous publication sparked sharp criticism from professional philosophers of science for conflating and confusing key concepts. Moreover, there is strikingly little consideration of Bayesian approaches to scientific reasoning, on which there has been much progress in recent years. Given the central role assigned to subjectivity in such approaches, and Sokal's concern about the role of subjectivity in science, their cursory treatment here is disappointing - and also makes the treatment seem somewhat dated.
In the final set of essays, Sokal returns to the broader implications of his thesis, and in particular the interaction of pseudo-science and postmodernism with politics and religion. He makes a powerful case for the dire effect the anything-goes mindset can have on attempts to challenge fundamentalism and extremism.
Perhaps the biggest problem with this collection is that it fails to reflect the fact that Sokal's concerns are now widely shared - and that progress is being made in addressing them, the emergence of evidence-based social policy being an obvious example. His critique would also gain more credibility from encompassing his own community: the failure of scientific institutions to address the abuse of statistical methods or promote systematic reviews is no less of a threat to progress than the ramblings of postmodernists or fundamentalists.
In the end, however, Sokal's essays - and his hoax - achieve their purpose of reminding us all that, in the words of the Victorian mathematician-philosopher William Clifford, "It is wrong, always, everywhere and for any one, to believe anything upon insufficient evidence."
"No matter what else I may do in my life," Alan Sokal says, "the hoax will almost certainly make up the start of my obituary."
He admits that the media attention he received for the 1996 spoof article published in Social Text was unexpected and slightly overwhelming for what was meant to be an academic comment on an academic problem. Not that he is shying away from the spotlight - he just wants the spotlight shifted to his new concerns with pseudo-science and its use in politics.
But while Sokal would like to intervene in public debates, he sees his foray into the social sciences and philosophy as his second career, and now that this latest book is out, he is aiming to return to what he lovingly describes as his "first career" of research in statistical mechanics, splitting his time between University College London and New York University.
So how would he like to be described in his obituary? "Neither the right-wing nor the left-wing found him politically correct," he says with glee.
Beyond the Hoax: Science, Philosophy and Culture
By Alan Sokal
Oxford University Press
Published 13 March 2008