An Unheralded Breakthrough: The Rosetta Stone of Mathematics

From Scientific American:

DeligneThere is no Nobel Prize in mathematics, but in 2001 the Norwegian government established a million-dollar Abel Prize, which is widely considered as an equivalent of the Nobel for mathematicians. This year’s prize was awarded to Pierre Deligne, professor emeritus at the Institute for Advanced Study in Princeton, N.J. Today, he is honored at a ceremony held in Oslo. Deligne’s most spectacular results are on the interface of two areas of mathematics: number theory and geometry. At first glance, the two subjects appear to be light-years apart. As the name suggests, number theory is the study of numbers, such as the familiar natural numbers (1, 2, 3, and so on) and fractions, or more exotic ones, such as the square root of two. Geometry, on the other hand, studies shapes, such as the sphere or the surface of a donut. But French mathematician André Weil had a penetrating insight that the two subjects are in fact closely related. In 1940, while Weil was imprisoned for refusing to serve in the army during World War II, he sent a letter to his sister Simone Weil, a noted philosopher, in which he articulated his vision of a mathematical Rosetta stone. Weil suggested that sentences written in the language of number theory could be translated into the language of geometry, and vice versa. “Nothing is more fertile than these illicit liaisons,” he wrote to his sister about the unexpected links he uncovered between the two subjects; “nothing gives more pleasure to the connoisseur.” And the key to his groundbreaking idea was something we encounter everyday when we look at the clock.

If we start working at 10:00 in the morning and work for eight hours, when do we finish? Well, 10 + 8 = 18, so a natural thing to say would be: “We finish at 18 o’clock.” This would be perfectly fine to say in France, where hours are recorded as numbers from zero to 24 (actually, not so fine, because a workday in France is usually limited to seven hours). But in the U.S. we say: “We finish at 6:00 pm.” How do we get six out of 18? We subtract 12: 18 – 12 = 6. Mathematicians call this “addition modulo 12.” Likewise, we can do addition modulo any whole number N. Just imagine a clock in which there are N hours instead of 12. For each N, we then obtain an esoteric-looking numerical system, in which we can do addition and multiplication, just like with ordinary numbers. For many years these systems looked, even to math practitioners, like something that would never have any real-world applications. In fact, English mathematician G.H. Hardy wrote, with defiance and pride, of the “uselessness” of number theory. But the joke was on him: these numerical systems are now ubiquitous in the encryption algorithms used in online banking. Every time we make a purchase online, arithmetic modulo N springs into action!

More here.

Why is Europe so Messed Up? An Illuminating History

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John Cassidy in The New Yorker:

When the Great Recession struck, U.S. policymakers did what mainstream textbooks recommend: they introduced monetary and fiscal-stimulus programs, which helped offset the retrenchments and job losses in the private sector. In Europe, austerity has been the order of the day, and it still is. Nearly five years after the financial crisis, governments are still trimming spending and cutting benefits in a vain attempt to bring down their budget deficits.

The big mystery isn’t why austerity has failed to work as advertised: anybody familiar with the concept of “aggregate demand” could explain that one. It is why an area with a population of more than three hundred million has stuck with a policy prescription that was discredited in the nineteen-twenties and thirties. The stock answer, which is that austerity is necessary to preserve the euro, doesn’t hold up. At this stage, austerity is the biggest threat to the euro. If the recession lasts for very much longer, political unrest is sure to mount, and the currency zone could well break up.

So why is this woebegone approach proving so sticky? Some of the answers can be found in a timely and suitably irreverent new book by Mark Blyth, a professor of political economy at Brown: “Austerity: The History of a Dangerous Idea.” Adopting a tone that is by turns bemused and outraged, Blyth traces the intellectual and political roots of austerity back to the Enlightenment, and the works of John Locke, David Hume, and Adam Smith. But he also provides a sharp analysis of Europe’s current predicament, explaining how an unholy alliance of financiers, central bankers, and German politicians foisted a draconian and unworkable policy on an unsuspecting populace.

Unknown Mathematician Proves Elusive Property of Prime Numbers

Erica Klarreich in Wired:

Zhang3On April 17, a paper arrived in the inbox of Annals of Mathematics, one of the discipline’s preeminent journals. Written by a mathematician virtually unknown to the experts in his field — a 50-something lecturer at the University of New Hampshire named Yitang Zhang — the paper claimed to have taken a huge step forward in understanding one of mathematics’ oldest problems, the twin primes conjecture.

Editors of prominent mathematics journals are used to fielding grandiose claims from obscure authors, but this paper was different. Written with crystalline clarity and a total command of the topic’s current state of the art, it was evidently a serious piece of work, and the Annals editors decided to put it on the fast track.

Just three weeks later — a blink of an eye compared to the usual pace of mathematics journals — Zhang received the referee report on his paper.

“The main results are of the first rank,” one of the referees wrote. The author had proved “a landmark theorem in the distribution of prime numbers.”

Rumors swept through the mathematics community that a great advance had been made by a researcher no one seemed to know — someone whose talents had been so overlooked after he earned his doctorate in 1992 that he had found it difficult to get an academic job, working for several years as an accountant and even in a Subway sandwich shop.

More here.

Is the Brain No Different From a Light Switch? The Uncomfortable Ideas of the Philosopher Daniel Dennett

Jonathan Weiner in The Daily Beast:

ScreenHunter_201 May. 21 17.17For Daniel Dennett, philosophers are like blacksmiths: they make their own tools as they go along. Unlike carpenters, who have to buy their drills and saws at Sears, blacksmiths can use their own hammers, tongs, and anvils to pound out more hammers, tongs, and anvils. Dennett, whose famous white beard gives him the look of both a blacksmith and a philosopher, has been particularly industrious at the anvil. He has been working as a philosopher for 50 years, and in his new book, Intuition Pumps and Other Tools for Thinking, he shares a few tricks to make the hard work easier. He is a master at inventing tools for thought—metaphysical jokes, fables, parables, puzzles, and zany Monty-Python-like sketches that can help thinkers feel their way forward. Dennett calls them hand tools and power tools for the mind, and he’s built dozens and dozens of them over the years.

“Thinking is hard,” he writes. “Thinking about some problems is so hard that it can make your head ache just thinking about thinking about them.” Thinking tools help philosophers work on the really deep, hard questions about life, the universe, and everything. They facilitate what another philosopher has called Jootsing, which stands for Jumping Out Of the System—the goal is to pop out of the goldfish bowl of commonplace ideas without drowning in thin air. Think of Plato’s Cave, for instance. That little story has helped philosophers puzzle about the nature of reality for more than 23 centuries and counting.

Dennett’s own inventions include “Swampman Meets a Cow-Shark,” “Zombies and Zimboes,” and many other thought experiments that illuminate great questions in philosophy. He focuses on problems of free will, evolution, and consciousness. His ideas about consciousness are rather shocking; he can make you feel that the human brain itself is just a collection of tongs, hammers, and intuition pumps. (More about that in a moment.) Dennett has written more than a dozen books about those deep topics.

More here.

Mohsin Hamid: ‘Islam is not a monolith’

Mohsin Hamid in The Guardian:

MohsinIn 2007, six years after the terrorist attacks of 11 September 2001, I was travelling through Europe and North America. I had just published a novel, The Reluctant Fundamentalist, and as I travelled I was struck by the large number of interviewers and of audience members at Q&As who spoke of Islam as a monolithic thing, as if Islam referred to a self-contained and clearly defined world, a sort of Microsoft Windows, obviously different from, and considerably incompatible with, the Apple OS X-like operating system of “the west”.

I recall one reading in Germany in particular. Again and again, people posed queries relating to how “we Europeans” see things, in contrast to how “you Muslims” do. Eventually I was so exasperated that I pulled my British passport out of my jacket and started waving it around my head. “While it's true the UK hasn't yet joined the eurozone,” I said, ” I hope we can all agree the country is in fact in Europe.”

Six years on, a film inspired by the novel is in the process of appearing on screens around the world, and I am pleased to report that those sorts of questions are a little rarer now than they were in 2007. This represents progress. But it is modest progress, for the sense of Islam as a monolith lingers, in places both expected and unexpected.

More here.

germ houses

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Justin Sonnenburg, a microbiologist at Stanford, suggests that we would do well to begin regarding the human body as “an elaborate vessel optimized for the growth and spread of our microbial inhabitants.” This humbling new way of thinking about the self has large implications for human and microbial health, which turn out to be inextricably linked. Disorders in our internal ecosystem — a loss of diversity, say, or a proliferation of the “wrong” kind of microbes — may predispose us to obesity and a whole range of chronic diseases, as well as some infections. “Fecal transplants,” which involve installing a healthy person’s microbiota into a sick person’s gut, have been shown to effectively treat an antibiotic-resistant intestinal pathogen named C. difficile, which kills 14,000 Americans each year. (Researchers use the word “microbiota” to refer to all the microbes in a community and “microbiome” to refer to their collective genes.) We’ve known for a few years that obese mice transplanted with the intestinal community of lean mice lose weight and vice versa. (We don’t know why.) A similar experiment was performed recently on humans by researchers in the Netherlands: when the contents of a lean donor’s microbiota were transferred to the guts of male patients with metabolic syndrome, the researchers found striking improvements in the recipients’ sensitivity to insulin, an important marker for metabolic health. Somehow, the gut microbes were influencing the patients’ metabolisms.

more from Michael Pollan at the NY Times Magazine here.

the culture animal

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According to genetics, there is not much that makes us human; depending on how you count, we share 98.5 per cent of our genes with chimpanzees. Perhaps this is not such a significant matter, given that we also share about 60 per cent of our genes with tomatoes. As this shows, human beings are fully part of nature, and the elements that make us make not just the rest of the animal and vegetable kingdoms, but the rocks beneath our feet and the stars in the sky above us. So what does make us human? It is not that we live in social groups: ants, antelopes and sparrows do the same. It is not that we have nuanced emotional lives: so do dogs and baboons. It is not even that we have language, for other things – including trees, as it happens – have communication systems, too, and it might be that some of those systems are quite complex, as appears to be the case with dolphins, for example. But in the human case the system of communication – language – is particularly complex and flexible, with great expressive power, and this makes possible the phenomenon of culture. If I were to pick one thing that separates humanity from the rest of the living world, culture is it.

more from AC Grayling at The New Statesman here.

I am dust and ashes and full of sin

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In the summer of 1494, soon after his engagement, Albrecht Dürer made a startlingly intimate drawing of his fiancée Agnes Frey. One might have expected a twenty-three-year-old to depict his betrothed as a source of love, or comfort or well-being, all the more since her substantial dowry would soon launch his independent career. Instead, Albrecht showed Agnes twisted up in a knot of anxious introversion. She looks withdrawn and preoccupied, and the circles under her heavy-lidded eyes may even make one think she has been crying. In its frank portrayal of an informal moment of unguarded emotion, there had never been a drawing quite like this before. Typically portraiture was honorific and meant to represent the exemplary virtues of the person shown; Dürer instead often sought to capture the idiosyncratic and psychological characteristics of the people he portrayed. He was fascinated with the close scrutiny of dark and brooding emotion. This is especially evident in his self-portraits, many of which show him in states of melancholy, doubt, or disease.

more from Andrew Butterfield at the NYRB here.

Tuesday Poem

Jerusalem
.
And did those feet in ancient time
Walk upon Englands mountains green:
And was the holy Lamb of God,
On Englands pleasant pastures seen!
And did the Countenance Divine,
Shine forth upon our clouded hills?
And was Jerusalem builded here,
Among these dark Satanic Mills?
Bring me my Bow of burning gold:
Bring me my arrows of desire:
Bring me my Spear: O clouds unfold!
Bring me my Chariot of fire!
I will not cease from Mental Fight,
Nor shall my sword sleep in my hand:
Till we have built Jerusalem,
In Englands green & pleasant Land.
.
>
by William Blake

Aftermath: Pakistan Elections 2013

by Omar Ali

ImagesThe May 11th elections in Pakistan represented the first time that a civilian regime completed its term in office and held elections in which power will be transferred democratically to a new civilian regime. In a country where the security establishment has a long history of throwing out elected regimes and manipulating results, this in itself was an important landmark. For this (and for very little else, unfortunately) we can thank President Zardari and his coalition building skills and stubborn determination.

For my pre-election predictions, see here. For immediate post-result thoughts, see here.

In the short election campaign the Pakistan Tehreek e Insaf (PTI) of Imran Khan captured the imagination of the newly educated and elite classes but it did not have the time (and/or the ability) to catch up with the pre-poll favorite, the PMLN. The superior and far more detailed groundwork done by the PMLN while it ruled Punjab for 5 years, its stronger slate of candidates, its relatively energetic performance in the Punjab government, and Mian Nawaz Sharif’s improved reputation, (along with a PPP collapse) led to a PMLN landslide in Punjab. This has practically given the PMLN a simple majority in the national assembly in spite of having only a handful of seats outside Punjab. The newcomer PTI will form a coalition government in KP; PPP, with or without MQM, will rule again in Sindh; and Balochistan remains a unique case, completely outside the national mainstream.

With daily bombings by the Taliban keeping a check on the ANP, PPP and (to some extent) the MQM, and with an insurgency and its frequently vicious suppression going on in Balochistan, traditional campaigning was mostly confined to Punjab. There, an almost millenarian excitement took hold of the middle class in the course of the PTI campaign; This phenomenon was most visible on social media and in the better neighborhoods of urban centers. Meeting each other at coffee spots and snack bars and pushing “like” buttons on each other’s facebook pages, the newly energized middle class supporters of Imran Khan managed to convince themselves that a complete root and branch renovation of Pakistan under brand new leadership was on the cards.

Read more »

Digging Up Bones or, The Labyrinths beneath Our Feet

by Tom Jacobs

Labyrinth1There is a story that I want to tell you. It's about a man who lives alone at the edge of town. In a small house without much to recommend it. He finds that there is little for him to do other than to look out the window. Which is something that he does. A lot. Most every day and for most of each of those days. He looks out this window, examining the microscopy of the world outside his window, paying close attention. This is what he does. It provides a certain amount of pleasure to him.

Some begin to worry that he's losing his mind. He begins to think that he is approaching some kind of revelation. Who is to say which is which? Maybe it can be both.

He begins a project. He begins to examine the surfaces of his home, convinced that there is something beneath or behind. The floors, the walls, the ceilings. Eventually he finds himself in the basement, palpating a crack that runs through the middle of his foundation. He becomes convinced that there is something shouldering itself into the floor of his basement from below. So he begins to excavate. As he digs he finds what he believes to be a labyrinth. He excavates this labyrinth like an archaeologist over the course of many years. As he unearths the whole intricate thing he becomes convinced that there is some great secret there, some infinite thing of happiness and hope. He continues to excavate and explore the labyrinth but can never find his way through. Knowing in his heart that that he's uncovered something important, he goes out into the street to tell someone about it. This is the first time he's left his house for as long as he can remember.

The first person he finds is a man who lives down the block and happens to be passing by. He tells him about what he's found. The man is skeptical but intrigued.

Together they go back to his house so that he might show him his labyrinth. They explore the labyrinth. The man on the street had read somewhere that if you keep your hand on the wall, you will eventually find your way in (or out). Eventually they find the center of the labyrinth. At the center there is a door in the floor. They open the door and, holding hands, they walk together, through. And then they disappear and are never heard from again.

Read more »

New Air In A Fast City

by Mara Jebsen

TnShould poetry be whispered in the dark? Should it be a communion with the dead, transacted silently through the media of paper and lamplight? Ought it to roll out of the whale-mouths of men on stages (maybe grumpy orators in black fedoras?) Should it arrive from the mouths of girls in sequins and combat boots—or from the mouths of boys in sequins and combat boots—whose whiskey-voices crackle in the backs of bars? Should teachers with elbow patches pass it out in stacks? Does it die in the air if badly read?

The questions are both important and silly. Asking them is like comparing ways of worship. I can’t say that it is better to shout and clap your devotion than it is to believe one must preserve a holy silence. The question is always: how do you honor a text?

On a bright May Wednesday evening in New York, I left the writing class I teach in a dark movie-viewing room in the basement of the NYU’s Tisch building. I stopped in the hall to nervously apply red lipstick, and then I boarded the subway on a secret mission.

I met my co-conspirators beside a fountain in Bryant Park. It was one of those first Spring days in the city—when the late light is white-wine colored and everything feels about to explode. Two journalists with camera and microphone arrived to record our experiment, and their presence was both unnerving and comforting. The camera seemed to legitimize our odd project. But part of the project’s ethos is that it doesn’t need legitimizing.

This was my first time. Members of PUP (Poets in Unexpected Places) have been performing poems on ferries, in laundromats and in subways around NYC for a while. I’ve known a number of its members for as long as ten years and asked to join the group months ago. But at the last minute I’d always chicken out.

Read more »

NORTH KOREA’S NERVE WAR

by James McGirk

2012071201146_0The Moranbong Band is best imagined as a North Korean version of Celtic Woman: an all-female ensemble band swaddled in fetching formalwear, blasting highly produced, energetic nationalist kitsch. Of course, no matter how much vigorous fiddling Chloe, Lisa, Susan and Mairead can manage, Celtic Woman is unlikely to attract as much scrutiny from intelligence agencies as the Moranbong Band’s cover of Bill Conti’s “Gonna Fly Now”, which is perhaps better known as the theme from Rocky, and was performed – complete with a video backdrop featuring cuts of Sylvester Stallone working out – for none other than Kim Jong-un, the number one of the sinister and secretive Democratic People’s Republic of Korea.

Peculiar things have been crossing North Korea watchers’ desks lately. Witness The Sun’s revelation that Kim Jong-un’s father liked to nosh on hippo meat, spider and snake sushi. Or how in March, Kim Jong-un took time away from playing nuclear chicken to host flamboyant former NBA player Dennis Rodman. (Rodman says he’s been invited back for another visit in August.)

Decadent as this behavior might seem for the rulers of one of the world’s poorest countries, Kim Jong-un’s oddball behavior suggests a media-savvy spin on a classic diplomatic game. George Freidman, leading analyst and CEO of the geopolitical analysis firm STRATFOR, describes North Korea’s decades-old strategy of prying subsidies from its neighbors as “fearsome, weak and crazy.”

Fearsome is easy to understand. The South Korean capital, Seoul, is within howitzer-range of the DPRK’s enormous Cold War-vintage army. A sneak attack could kill hundreds of thousands of people and rip apart one of the world’s most important manufacturing centers. And that’s assuming the DPRK confines itself to conventional munitions: North Korea tested an atomic weapon in 2009 and probably has cheap, nasty weapons of mass destruction (germs and gas) stockpiled and ready to go. North Korea’s population is even scarier. They’re kept on the brink of starvation and forbidden from any contact with the outside world. Children are raised ready for war and taught to adore their leaders and obey without question. This is a frightful enemy, but it’s also a weak one.
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POETRY IN TRANSLATION: CORDOBA

(Written in 1932 on Spanish soil,
mainly in the Mosque of Cordoba)

BY MOHAMMED IQBAL

I
Chain of day and night
Fashioner of events
Basis of life and death
Two tone silken thread
Fiber of attributes
Pitch of prospects
Chain of day and night
Sitting in judgment
Setting a value on us
When we're lacking
Death is your destiny
Death is my destiny
What else is reality
The flow of one age
Neither day nor night
All crafts vanish
Black and white fade
Annihilation the end

II
But in this form
Hues of eternal life
Splendor of man's love
Love is life's base
Death has no claim on love
Love itself the tide
Stemming the torrent
Love is unnamed eras
Love is Gabriel's breath
Love is the Prophet of God
Love is the Word of God
Love is the radiant rose
Love is raw wine
Love the goblet of kings
Love draws life's music
Love is passion for life
Love is fire of life

Read more »

The Bystander Effect in Medical Care. Why Do I Have So Many Doctors Not Taking Care of Me?

by Carol A Westbrook

Japanese-doctorsIn a recent editorial in the New England Journal of Medicine1, Drs. Stavert and Lott used the tem, “The Bystander Effect,” to describe a new health care phenomenon, in which multiple physicians participate in the care of a patient, while none acknowledges primary responsibility for managing it. In their example, a patient was hospitalized with an undiagnosed, complicated illness, and over 40 physicians were involved in his care, yet none stepped forward to take charge.

The term “Bystander Effect” was coined after the 1964 stabbing murder of Kitty Genovese in New York City, which was witnessed by 38 people, none of whom intervened or called for help. The term refers to the tendency of people to be less likely to offer help in emergency situations when other people are present. In other words, it's not my problem, someone else can take charge.

Stavert and Lott argued that the Bystander Effect is becoming prevalent because of the way our system of hospital care has evolved. But I have noticed it is beginning to appear in the outpatient setting as well, where it is eroding the quality of medical care while increasing its expense.

Consider Mr. Miller, a fictional patient referred to me for anemia. I ordered blood tests, referred him for a colonoscopy, and scheduled a return visit in 2 weeks. During those two weeks, he also saw his cardiologist (heart), his orthopedist (joints), his urologist (prostate), his internist (blood pressure), his primary care physician (cholesterol). Mr. Miller is elderly and retired. When I asked him what he does with his leisure time, and he replied, “What free time? My wife and I spend most of our day in the doctor's office.” From my perspective, Mr. Miller received the expert attention of 7 highly trained medical specialists, and the best possible medical care in the world. From his perspective, he has to deal with two more doctors, more prescription medications to use up his limited income, and no assurance that any of this will make him feel better or live longer.

It is disheartening to see an elderly couple who measure out their days by the number of doctors' visits in a week. It is frustrating for their caregivers, who try their best to attend these multiple clinic visits. And it is dangerous, as multiple physicians may give contradictory recommendations, prescribe medications that interact, and overlook test results ordered by another doctor.

Mr. Miller is definitely getting more medical care than he would have received, say, 10 years ago. But is he getting better care? For that matter, is he even getting care?

Read more »

Clinical trial supports use of Kava to treat anxiety

From Kurzweil AI:

KavaA world-first completed clinical study by an Australian team has found Kava, a medicinal South Pacific plant, significantly reduced the symptoms of people suffering anxiety. The study, led by the University of Melbourne, revealed Kava could be an alternative to pharmaceutical products for the hundreds of thousands of Australians who suffer from generalized anxiety disorders (GAD) “In this study we’ve been able to show that Kava offers a potential natural alternative for the treatment of chronic clinical anxiety; unlike some other options, it has less risk of dependency and less potential for side effects,” said lead researcher, Dr Jerome Sarris from Department of Psychiatry at the University of Melbourne. The study also found that people’s genetic differences (polymorphisms) of certain neurobiological mechanisms called GABA transporters may modify their response to Kava. “If this finding is replicated, it may pave the way for simple genetic tests to determine which people may be likely to have a beneficial anxiety-reducing effect from taking Kava,” Sarris said.

An additional novel finding of the study, recently published in Phytotherapy Research, was that Kava increased women’s sex drive compared to those in the placebo group, believed to be due to the reduction of anxiety, rather than any aphrodisiac effect. Future studies confirming the genetic relationship to therapeutic response, and any libido-improving effects from Kava is now required. Dr Sarris said these significant findings are of importance to sufferers of anxiety and to the South Pacific region, which relies on Kava as a major export.

More here.

SNL’s Ben Affleck Episode: 5 Best Scenes

From The Atlantic:

Stefon-e1323264582113The season finale marked the last regular SNL appearance of Seth Meyers (slated to succeed Jimmy Fallon as host of NBC's Late Night), Fred Armisen, and Bill Hader. (Jason Sudeikis's return remains uncertain.) The show sent them off with a mostly strong episode and some fitting farewell moments. Host Ben Affleck was joined by his wife, Jennifer Garner, during the monologue. Amy Poehler joined Seth Meyers for Weekend Update. Musical guest Kanye West performed “Black Skinhead” and “New Slaves.”

Picture: Seth Meyers beats out Anderson Cooper for Stefon's hand in marriage.

More here.

Habermas, Adorno, Politics

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Richard Marshall interviews Gordon Finlayson in 3:AM Magazine:

3:AM: A key discussion in contemporary liberal theory of ethics and politics is the relationship and differences between Habermas and Rawls. Can you say something about what you take the main points of dispute are and where you stand on this?

GF: Sure. In my view, despite the amount of ink that has been spilt on Habermas and Rawls in their respective fields, relatively little attention has been paid to the dispute between them. This is largely because influential commentators and critics were quick to judge their exchange in the Journal of Philosophy a damp squib.

This was in part because expectations ran high, at the time, because two of the greatest social and political theorists of the 20th century, although working in different traditions, roughly analytic political philosophy and German Social theory had engaged each other in debate. It was also because in truth neither thinker was sufficiently well apprised of the detail of the others theory – unsurprisingly really, since they worked in very different traditions and each had just spent the last few years writing their own major work of political theory. Finally, everyone at the time, including the disputants themselves, were seduced by the assumption that the salient point of comparison between their respective theories was Habermas’s principle (U) and his conception of the moral standpoint, and Rawls’s argument that the principles of justice are those that would be chosen by a rational and reasonable persons in the Original Position. Almost everyone who has written on Habermas and Rawls makes that particular mistake.

My take on that is straightforward. The debate between them concerns their respective political theories. It is basically a dispute between Rawls’s theory of Political Liberalism, and Habermas’s Discourse Theory of Law. It is not primarily a dispute between Rawls’s A Theory of Justice, and Habermas Discourse Ethics. Principle (U) is the central idea in Habermas’s Discourse Ethics, which is a moral theory, not a theory of law or of democratic legitimacy, while the argument from the Original Position takes a back seat in Rawls’s Political Liberalism. People who interpret the Habermas Rawls dispute in the light of the contrast between Habermas’s principle (U) and Rawls’s Original Position, are looking at the wrong thing and so miss the real points of dispute.

What people should have been asking is this. What are the central organizing ideas of their respective political theories, and on what significant points do these ideas conflict?