All the ghosts in the machine

Reading All the Ghosts in the Machine: Illusions of immortality in the digital age by Elaine Kasket for New Scientist, 22 June 2019

Moving first-hand interviews and unnervingly honest recollections weave through psychologist Elaine Kasket’s first mainstream book, All the Ghosts in the Machine, an anatomy of mourning in the digital age. Unravelling that architecture turns up two distinct but complementary projects.

The first offers some support and practical guidance for people (and especially family members) who are blindsided by the practical and legal absurdities generated when people die in the flesh, while leaving their digital selves very much alive.

For some, the persistence of posthumous data, on Facebook, Instagram or some other corner of the social media landscape, is a source of “inestimable comfort”. For others, it brings “wracking emotional pain”. In neither case is it clear what actions are required, either to preserve, remove or manage that data. As a result, survivors usually oversee the profiles of the dead themselves – always assuming, of course, that they know their passwords. “In an effort to keep the profile ‘alive’ and to stay connected to their dead loved one,” Kasket writes, “a bereaved individual may essentially end up impersonating them.”

It used to be the family who had privileged access to the dead, to their personal effects, writings and photographs. Families are, as a consequence, disproportionately affected by the persistent failure of digital companies to distinguish between the dead and the living.

Who has control over a dead person’s legacy? What unspoken needs are being trammelled when their treasured photographs evaporate or, conversely, when their salacious post-divorce Tinder messages are disgorged? Can an individual’s digital legacy even be recognised for what it is in a medium that can’t distinguish between life and death?

Kasket’s other project is to explore this digital uncanny from a psychoanalytical perspective. Otherwise admirable 19th-century ideals of progress, hygiene and personal improvement have conned us into imagining that mourning is a more or less understood process of “letting go”. Kasket’s account of how this idea gained currency is a finely crafted comedy of intellectual errors.

In fact, grief doesn’t come in stages, and our relationships with the dead last far longer than we like to imagine. All the Ghosts in the Machine opens with an account of the author’s attempt to rehabilitate her grandmother’s bitchy reputation by posting her love letters on Instagram.

“I took a private correspondence that was not intended for me and transformed it from its original functions. I wanted it to challenge others’ ideas, and to affect their emotions… Ladies and gentlemen of today, I present to you the deep love my grandparents held for one another in 1945, ‘True romance’, heart emoticon.”

Eventually, Kasket realised that the version of her grandmother her post had created was no more truthful than the version that had existed before. And by then, of course, it was far too late.

The digital persistence of the dead is probably a good thing in these dissociated times. A culture of continuing bonds with the dead is much to be preferred over one in which we are all expected to “get over it”. But, as Kasket observes, there is much work to do, for “the digital age has made continuing bonds easier and harder all at the same time.”

Asking for it

Capital is not the point here. Neither is capitalism. The point is our relationship with information. Amazon’s algorithms are sucking all the localism out of the retail system, to the point where whole high streets have vanished — and entire communities with them. Amazon is in part powered by the fatuous metricisation of social variety through systems of scores, rankings, likes, stars and grades, which are (not coincidentally) the methods by which social media structures — from clownish Twitter to China’s Orwellian Social Credit System — turn qualitative differences into quantitative inequalities.

Reading The Metric Society: On the Quantification of the Social by Steffen Mau (Polity Press) for the Times Literary Supplement, 30 April 2019 

A series of apparently impossible events

Exploring Smoke and Mirrors at Wellcome Collection for New Scientist, 1 May 2019

ACCORDING to John Nevil Maskelyne, “a bad conjurer will make a good medium any day”. He meant that, as a stage magician in 19th-century London, he had to produce successful effects night after night, while rivals who claimed their illusions were powered by the spirit world could simply blame a bad set on “unhelpful spirits”, or even on the audience’s own scepticism.

A gaffe-ridden performance in the UK by one set of spiritualists, the US Davenport Brothers, drove Maskelyne to invent his own act. With his friend, the cabinet maker George Alfred Cooke, he created an “anti-spiritualist” entertainment, at once replicating and debunking the spiritualist movement’s stock-in-trade effects.

Matthew Tompkins teases out the historical implications of Maskelyne’s story in The Spectacle of Illusion: Magic, the paranormal and the complicity of the mind (Thames & Hudson). It is a lavishly illustrated history to accompany Smoke and Mirrors, a new and intriguing exhibition at the Wellcome Collection in London.

Historical accident was partly responsible. In 1895, Guglielmo Marconi sent long-wave radio signals over a distance of a couple of kilometres, and, for decades after, hardly a year passed in which some researcher didn’t announce a new type of invisible ray. The world turned out to have aspects hidden from unaided human perception. Was it so unreasonable of people to speculate about what, or who, might lurk in those hidden corners of reality? Were they so gullible, reeling as they were from the mass killings of the first world war, to populate these invisible realms with their dead?

In 1924, the magazine Scientific American offered $2500 to any medium who could demonstrate their powers under scientific controls. The medium Mina “Margery” Crandon decided to try her hand, but she reckoned without the efforts of one Harry “Handcuff” Houdini, who eventually exposed her as a fraud.

Yet spiritualism persisted, shading off into parapsychology, quantum speculation and any number of cults. Understanding why is more the purview of a psychologist such as Gustav Kuhn, who, as well as being a major contributor to the show, offers insight into magic and magical belief in his own new book, Experiencing the Impossible (MIT Press).

Kuhn, a member of the Magic Circle, finds Maskelyne’s “anti-spiritualist” form of stage magic alive in the hands of illusionist Derren Brown. He suggests that Brown is more of a traditional magician than he lets on, dismissing the occult while he endorses mysterious psychological phenomena, mostly to do with “subconscious priming”, that, at root, are non-scientific.

Kuhn defines magic as “the experience of wonder that results from perceiving an apparently impossible event”. Definitions of what is impossible differ, and different illusions work for different people. You can even design it for animals, as a torrent of YouTube videos, based largely on Finnish magician Jose Ahonen’s “Magic for Dogs”, attest.

Tricking dogs is one thing, but why do our minds fall for magic? It was the 18th-century Scottish Enlightenment philosopher, David Hume, who argued that there is no metaphysical glue binding events, and that we only ever infer causal relationships, be they real or illusory.

Twinned with our susceptibility to wrongly infer relationships between events in the world is our ability to fool ourselves at an even deeper level. Numerous studies, including one by researcher and former magician Jay Olson and clinician Amir Raz which sits at the exit to the Wellcome show, conclude that our feeling of free will may be an essential trick of the mind.

Inferring connections makes us confident in ourselves and our abilities, and it is this confidence, this necessary delusion about the brilliance of our cognitive abilities, that lets us function… and be tricked. Even after reading both books, I defy you to see through the illusions and wonders in store at the exhibition.

Choose-your-own adventure

Reading The Importance of Small Decisions by Michael O’Brien, R. Alexander Bentley and William Brock for New Scientist, 13 April 2019

What if you could map all kinds of human decision-making and use it to chart society’s evolution?

This is what academics Michael O’Brien, Alexander Bentley and William Brock try to do in The Importance of Small Decisions. It is an attempt to expand on a 2014 paper, “Mapping collective behavior in the big-data era”, that they wrote in Behavioral and Brain Sciences . While contriving to be somehow both too short and rambling, it bites off more than it can chew, nearly chokes to death on the ins and outs of group selection, and coughs up its best ideas in the last 40 pages.

Draw a graph. The horizontal axis maps decisions according to how socially influenced they are. The vertical axis tells you how clear the costs and pay-offs are for each decision. Rational choices sit in the north-western quadrant of the map. To the north-east, bearded capuchins teach each other how to break into palm nuts in a charming example of social learning (pictured). Twitter storms generated by fake news swirl about the south-east.

The more choices you face, the greater the cognitive load. The authors cite economist Eric Beinhocker, who in The Origin of Wealth calculated that human choices had multiplied a hundred million-fold in the past 10,000 years. Small and insignificant decisions now consume us.

Worse, costs and pay-offs are increasingly hidden in an ocean of informational white noise, so that it is easier to follow a trend than find an expert. “Why worry about the underlying causes of global warming when we can see what tens of millions of our closest friends think?” ask the authors, building to a fine, satirical climax.

In an effort to communicate widely, the authors have, I think, left out a few too many details from their original paper. And a mid-period novel by Philip K. Dick would paint a more visceral picture of a world created by too much information. Still, there is much fun to be had reading the garrulous banter of these three extremely smart academics.

Come on, Baggy, get with the beat!

Reading The Evolving Animal Orchestra: In search of what makes us musical by Henkjan Honing for New Scientist, 6 April 2019

The perception, if not the enjoyment, of musical cadences and of rhythm,” wrote Darwin in his 1871 book The Descent of Man, “is probably common to all animals.”

Henkjan Honing has tested this eminently reasonable idea, and in his book, The Evolving Animal Orchestra, he reports back. He details his disappointment, frustration and downright failure with such wit, humility and a love of the chase that any young person reading it will surely want to run away to become a cognitive scientist.

No culture has yet been found that doesn’t have music, and all music shares certain universal characteristics: melodies composed of seven or fewer discrete pitches; a regular beat; a limited sequence of rhythmic patterns. All this would suggest a biological basis for musicality.

A bird flies with regular beats of its wings. Animals walk with a particular rhythm. So you might expect beat perception to be present in everything that doesn’t want to falter when moving. But it isn’t. Honing describes experiments that demonstrate conclusively that we are the only primates with a sense of rhythm, possibly deriving from advanced beat perception.

Only strongly social animals, he writes, from songbirds and parrots to elephants and humans, have beat perception. What if musicality was acquired by all prosocial species through a process of convergent evolution? Like some other cognitive scientists, Honing now wonders whether language might derive from music, in a similar way to how reading uses much older neural structures that recognise contrast and sharp corners.

Honing must now test this exciting hypothesis. And if The Evolving Animal Orchestra is how he responds to disappointment, I can’t wait to see what he makes of success.

And so we wait

In the 1996 comedy film Swingers, Jon Favreau plays Mike, a young man in love with love, and at war with the answerphones of the world. “Hi,” says one young woman’s machine, “this is Nikki. Leave a message,” prompting Mike to work, flub after flub, through an entire, entirely fictitious, relationship with the absent Nikki. “This just isn’t working out,” he sighs, on about his 20th attempt to leave a message that is neither creepy nor incoherent. “I – I think you’re great, but, uh, I – I… Maybe we should just take some time off from each other. It’s not you, it’s me. It’s what I’m going through.”

Thinking about Delayed Response by Jason Farman (Yale) for the Telegraph, 6 February 2019.

Making abstract life

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Talking to the design engineer Yamanaka Shunji for New Scientist, 23 January 2019

Five years ago, desktop 3D printers were poised to change the world. A couple of things got in the way. The print resolution wasn’t very good. Who wants to drink from a tessellated cup?

More important, it turned out that none of us could design our way out of a wet paper bag.

Japanese designer Yamanaka Shunji calls forth one-piece walking machines from vinyl-powder printers the way the virtuoso Phyllis Chen conjures concert programmes from toy pianos. There’s so much evident genius at work, you marvel that either has time for such silliness.

There’s method here, of course: Yamanaka’s X-Design programme at Keio University turns out objects bigger than the drums in which they’re sintered, by printing them in folded form. It’s a technique lifted from space-station design, though starry-eyed Western journalists, obsessed with Japanese design, tend to reach for origami metaphors.

Yamanaka’s international touring show, which is stopping off at Japan House in London until mid-March, knows which cultural buttons to press. The tables on which his machine prototypes are displayed are steel sheets, rolled to a curve and strung under tension between floor and ceiling, so visitors find themselves walking among what appear to be unfolded paper scrolls. If anything can seduce you into buying a £100 sake cup when you exit the gift shop, it’s this elegant, transfixing show.

“We often make robots for their own sake,” says Yamanaka, blithely, “but usefulness is also important for me. I’m always switching between these two ways of thinking as I work on a design.”
The beauty of his work is evident from the first. Its purpose, and its significance, take a little unpacking.

Rami, for example: it’s a below-the-knee running prosthesis developed for the athlete Takakura Saki, who represented Japan during the 2012 Paralympics. Working from right to left, one observes how a rather clunky running blade mutated into a generative, organic dream of a limb, before being reined back into a new and practical form. The engineering is rigorous, but the inspiration was aesthetic: “We hoped the harmony between human and object could be improved by re-designing the thing to be more physically attractive.”

Think about that a second. It’s an odd thing to say. It suggests that an artistic judgement can spur on and inform an engineering advance. And so, it does, in Yamanaka’s practice, again, and again.

Yamanaka, is an engineer who spent much of his time at university drawing manga, and cut his teeth on car design at Nissan. He wants to make something clear, though: “Engineering and art don’t flow into each other. The methodologies of art and science are very different, as different as objectivity and subjectivity. They are fundamental attitudes. The trick, in design, is to change your attitude, from moment to moment.” Under Yamanaka’s tutelage, you learn to switch gears, not grind them.

Eventually Yamanaka lost interest in giving structure and design to existing technology. “I felt if one could directly nurture technological seeds, more imaginative products could be created.” It was the first step on a path toward designing for robot-human interaction.

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Yamanaka – so punctilious, so polite – begins to relax, as he contemplates the work of his peers: Engineers are always developing robots that are realistic, in a linear way that associates life with things, he says, adding that they are obsessed with being more and more “real”. Consequently, he adds, a lot of their work is “horrible. They’re making zombies!”

Artists have already established a much better approach, he explains: quite simply, artists know how to sketch. They know how to reduce, and abstract. “From ancient times, art has been about the right line, the right gesture. Abstraction gets at reality, not by mimicking it, but by purifying it. By spotting and exploring what’s essential.”

Yamanaka’s robots don’t copy particular animals or people, but emerge from close observation of how living things move and behave. He is fascinated by how even unliving objects sometimes seem to transmit the presence of life or intelligence. “We have a sensitivity for what’s living and what’s not,” he observes. “We’re always searching for an element of living behaviour. If it moves, and especially if it responds to touch, we immediately suspect it has some kind of intellect. As a designer I’m interested in the elements of that assumption.”

So it is, inevitably, that the most unassuming machine turns out to hold the key to the whole exhibition. Apostroph is the fruit of a collaboration with Manfred Hild, at Sony’s Computer Science Laboratories in Paris. It’s a hinged body made up of several curving frames, suggesting a gentle logarithmic spiral.

Each joint contains a motor which is programmed to resist external force. Leave it alone, and it will respond to gravity. It will try to stand. Sometimes it expands into a broad, bridge-like arch; at other times it slides one part of itself through another, curls up and rolls away.

As an engineer, you always follow a line of logic, says Yamanaka. You think in a linear way. It’s a valuable way of proceeding, but unsuited to exploration. Armed with fragile, good-enough 3D-printed prototypes, Yamanaka has found a way to do without blueprints, responding to the models he makes as an artist would.

In this, he’s both playing to his strengths as a frustrated manga illustrator, and preparing his students for a future in which the old industrial procedures no longer apply. “Blueprints are like messages which ensure the designer and manufacturer are on the same page,” he explains. “If, however, the final material could be manipulated in real time, then there would be no need to translate ideas into blueprints.”

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It’s a seductive spiel but I can’t help but ask what all these elegant but mostly impractical forms are all, well, for.

 

Yamanaka’s answer is that they’re to make the future bearable. “I think the perception of subtle lifelike behaviour is key to communication in a future full of intelligent machines,” he says. “Right now we address robots directly, guiding their operations. But in the future, with so many intelligent objects in our life, we’ll not have the time or the patience or even the ability to be so precise. Body language and unconscious communication will be far more important. So designing a lifelike element into our machines is far more important than just tinkering with their shape.”

By now we’ve left the gallery and are standing before Flagella, a mechanical mobile made for Yamanaka’s 2009 exhibition Bones, held in Tokyo Midtown. Flagella is powered by a motor with three units that repeatedly rotate and counter-rotate, its movements supple and smooth like an anemone. It’s hard to believe the entire machine is made from hard materials.

There’s a child standing in front of it. His parents are presumably off somewhere agonising over sake cups, dinky tea pots, bowls that cost a month’s rent. As we watch, the boy begins to dance, riffing off the automaton’s moves, trying to find gestures to match the weavings of the machine.

“This one is of no practical purpose whatsoever,” Yamanaka smiles. But he doesn’t really think that. And now, neither do I.

Praying to the World Machine

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In late spring this year, the Barbican Centre in London will explore the promise and perils of artificial intelligence in a festival of films, workshops, concerts, talks and exhibitions. Even before the show opens, however, I have a bone to pick: what on earth induced the organisers to call their show AI: More than human?

More than human? What are we being sold here? What are we being asked to assume, about the technology and about ourselves?

Language is at the heart of the problem. In his 2007 book, The Emotion Machine, computer scientist Marvin Minsky deplored (although even he couldn’t altogether avoid) the use of “suitcase words”: his phrase for words conveying specialist technical detail through simple metaphors. Think what we are doing when we say metal alloys “remember” their shape, or that a search engine offers “intelligent” answers to a query.

Without metaphors and the human tendency to personify, we would never be able to converse, let alone explore technical subjects, but the price we pay for communication is a credulity when it comes to modelling how the world actually works. No wonder we are outraged when AI doesn’t behave intelligently. But it isn’t the program playing us false, rather the name we gave it.

Then there is the problem outlined by Benjamin Bratton, director of the Center for Design and Geopolitics at the University of California, San Diego, and author of cyber bible The Stack. Speaking at Dubai’s Belief in AI symposium last year, he said we use suitcase words from religion when we talk about AI, because we simply don’t know what AI is yet.

For how long, he asked, should we go along with the prevailing hype and indulge the idea that artificial intelligence resembles (never mind surpasses) human intelligence? Might this warp or spoil a promising technology?

The Dubai symposium, organised by Kenric McDowell and Ben Vickers, interrogated these questions well. McDowell leads the Artists and Machine Intelligence programme at Google Research, while Vickers has overseen experiments in neural-network art at the Serpentine Gallery in London. Conversations, talks and screenings explored what they called a “monumental shift in how societies construct the everyday”, as we increasingly hand over our decision-making to non-humans.

Some of this territory is familiar. Ramon Amaro, a design engineer at Goldsmith, University of London, drew the obvious moral from the story of researcher Joy Buolamwini, whose facial-recognition art project The Aspire Mirror refused to recognise her because of her black skin.

The point is not simple racism. The truth is even more disturbing: machines are nowhere near clever enough to handle the huge spread of normal distribution on which virtually all human characteristics and behaviours lie. The tendency to exclude is embedded in the mathematics of these machines, and no patching can fix it.

Yuk Hui, a philosopher who studied computer engineering and philosophy at the University of Hong Kong, broadened the lesson. Rational, disinterested thinking machines are simply impossible to build. The problem is not technical but formal, because thinking always has a purpose: without a goal, it is too expensive a process to arise spontaneously.

The more machines emulate real brains, argued Hui, the more they will evolve – from autonomic response to brute urge to emotion. The implication is clear. When we give these recursive neural networks access to the internet, we are setting wild animals loose.

Although the speakers were well-informed, Belief in AI was never intended to be a technical conference, and so ran the risk of all such speculative endeavours – drowning in hyperbole. Artists using neural networks in their practice are painfully aware of this. One artist absent from the conference, but cited by several speakers, was Turkish-born Memo Akten, based at Somerset House in London.

His neural networks make predictions on live webcam input, using previously seen images to make sense of new ones. In one experiment, a scene including a dishcloth is converted into a Turneresque animation by a recursive neural network trained on seascapes. The temptation to say this network is “interpreting” the view, and “creating” art from it, is well nigh irresistible. It drives Akten crazy. Earlier this year in a public forum he threatened to strangle a kitten whenever anyone in the audience personified AI, by talking about “the AI”, for instance.

It was left to novelist Rana Dasgupta to really put the frighteners on us as he coolly unpicked the state of automated late capitalism. Today, capital and rental income are the true indices of political participation, just as they were before the industrial revolution. Wage rises? Improved working conditions? Aspiration? All so last year. Automation has  made their obliteration possible, by reducing to virtually nothing the costs of manufacture.

Dasgupta’s vision of lives spent in subjection to a World Machine – fertile, terrifying, inhuman, unethical, and not in the least interested in us – was also a suitcase of sorts, too, containing a lot of hype, and no small amount of theology. It was also impossible to dismiss.

Cultural institutions dabbling in the AI pond should note the obvious moral. When we design something we decide to call an artificial intelligence, we commit ourselves to a linguistic path we shouldn’t pursue. To put it more simply: we must be careful what we wish for.

Pierre Huyghe: Digital canvases and mind-reading machines

Visiting UUmwelt, Pierre Huyghe’s show at London’s Serpentine Gallery, for the Financial Times, 4 October 2018

On paper, Pierre Huyghe’s new exhibition at the Serpentine Gallery in London is a rather Spartan effort. Gone are the fictional characters, the films, the drawings; the collaborative manga flim-flam of No Ghost Just a Shell; the nested, we’re not-in-Kansas-any-more fictions, meta-fictions and crypto-documentaries of Streamside Day Follies. In place of Huyghe’s usual stage blarney come five large LED screens. Each displays a picture that, as we watch, shivers through countless mutations, teetering between snapshot clarity and monumental abstraction. One display is meaty; another, vaguely nautical. A third occupies a discomforting interzone between elephant and milk bottle.

Huyghe has not abandoned all his old habits. There are smells (suggesting animal and machine worlds), sounds (derived from brain-scan data, but which sound oddly domestic: was that not a knife-drawer being tidied?) and a great many flies. Their random movements cause the five monumental screens to pause and stutter, and this is a canny move, because without that  arbitrary grammar, Huyghe’s barrage of visual transformations would overwhelm us, rather than excite us. There is, in short, more going on here than meets the eye. But that, of course, is true of everywhere: the show’s title nods to the notion of “Umwelt” coined by the zoologist Jacob von Uexküll in 1909, when he proposed that the significant world of an animal was the sum of  things to which it responds, the rest going by virtually unnoticed. Huyghe’s speculations about machine intelligence are bringing this story up to date.

That UUmwelt turns out to be a show of great beauty as well; that the gallery-goer emerges from this most abstruse of high-tech shows with a re-invigorated appetite for the arch-traditional business of putting paint on canvas: that the gallery-goer does all the work, yet leaves feeling exhilarated, not exploited — all this is going to require some explanation.

To begin at the beginning, then: Yukiyasu Kamitani , who works at Kyoto University in Japan, made headlines in 2012 when he fed the data from fMRI brain scans of sleeping subjects into neural networks. These computer systems eventually succeeded in capturing shadowy images of his volunteers’ dreams. Since then his lab has been teaching computers to see inside people’s heads. It’s not there yet, but there are interesting blossoms to be plucked along the way.

UUmwelt is one of these blossoms. A recursive neural net has been shown about a million pictures, alongside accompanying fMRI data gathered from a human observer. Next, the neural net has been handed some raw fMRI data, and told to recreate the picture the volunteer was looking at.

Huyghe has turned the ensuing, abstruse struggles of the Kamitani Lab’s unthinking neural net into an exhibition quite as dramatic as anything he has ever made. Only, this time, the theatrics are taking place almost entirely in our own heads. What are we looking at here? A bottle. No, an elephant, no, a Francis Bacon screaming pig, goose, skyscraper, mixer tap, steam train mole dog bat’s wing…

The closer we look, the more engaged we become, the less we are able to describe what we are seeing. (This is literally true, in fact, since visual recognition works just that little bit faster than linguistic processing.) So, as we watch these digital canvases, we are drawn into dreamlike, timeless lucidity: a state of concentration without conscious effort that sports psychologists like to call “flow”. (How the Serpentine will ever clear the gallery at the end of the day I have no idea: I for one was transfixed.)

UUmwelt, far from being a show about how machines will make artists redundant, turns out to be a machine for teaching the rest of us how to read and truly appreciate the things artists make. It exercises and strengthens that bit of us that looks beyond the normative content of images and tries to make sense of them through the study of volume, colour, light, line, and texture. Students of Mondrian, Duffy and Bacon, in particular, will lap up this show.

Remember those science-fictional devices and medicines that provide hits of concentrated education? Quantum physics in one injection! Civics in a pill! I think Huyghe may have come closer than anyone to making this silly dream a solid and compelling reality. His machines are teaching us how to read pictures, and they’re doing a good job of it, too.

Prudery isn’t justice

Reading Objection: Disgust, morality, and the law by Debra Lieberman and Carlton Patrick for New Scientist, 15 September 2018

Ww want the law to be fair and objective. We also want laws that work in the real world, protecting and reassuring us, and maintaining our social and cultural values.

The moral dilemma is that we can’t have both. This may be because humans are hopelessly irrational and need a rational legal system to keep them in check. But it may also be that rationality has limits; trying to sit in judgement over everything is as cruel and farcical as gathering cats in a sack.

This dilemma is down to disgust, say Debra Lieberman, a psychologist at the University of Miami, and Carlton Patrick, a legal scholar at the University of Central Florida. In Objection, they join forces to consider why we find some acts disgusting without being reprehensible (like nose-picking), while others seem reprehensible without being disgusting (like drunk driving).

Disgust is such a powerful intuitive guide that it has informed our morality and hence our legal system. But it maps badly over a jurisprudence built on notions of harm and culpability.

Worse, terms of disgust are frequently wielded against people we intend to marginalise, making disgust a dangerously fissile element in our moral armoury.

Can science help us manage it? The prognosis is not good. If you were to ask a cultural anthropologist, a psychologist, a neuroscientist, a behavioural economist and a sociologist to explain disgust, you would receive different, often mutually contradictory, opinions.

The authors make their own job much more difficult, however, by endorsing a surreally naive model of the mind – one in which “both ’emotion’ and ‘cognition’ require circuitry” and it is possible to increase a child’s devotion to family by somehow manipulating this “circuitry”.

From here, the reader is ushered into the lollipop van of evolutionary psychology, where “disgust is best understood as a type of software program instantiated in our neural hardware”, which “evolved originally to guide our ancestors when making decisions about what to eat”.

The idea that disgust is to some degree taught and learned, conditioned by culture, class and contingency, is not something easily explored using the authors’ over-rigid model of the mind. Whenever they lay this model aside, however, they handle ambiguity well.

Their review of the literature on disgust is cogent and fair. They point out that although the decriminalisation of homosexuality and gay marriage argues persuasively for legal rationalism, there are other acts – like the violation of corpses – that we condemn without a strictly rational basis (the corpse isn’t complaining). This plays to the views of bioethicist Leon Kass, who calls disgust “the only voice left that speaks up to defend the central core of our humanity”.

Objection explores an ethical territory that sends legal purists sprawling. The authors emerge from this interzone battered, but essentially unbowed.