I have imagined, but not yet seen, the exhibition at the Victoria & Albert Museum ostensibly marking the bicentenary of the abolition of the slave trade. Uncomfortable Truths: The Shadow of Slave Trading on Contemporary Art and Design opens later this month, and the works have yet to be placed. Conceptual art was thereby born of necessity here - look at blank spaces and make the art in your head, as it is described by the animated curator Zoe Whitley, and from images on paper.
Whitley, an assertive African-American and a lofty international expert on contemporary art, is sharp and passionate. We wouldn't find obvious "black history" items in this collection, she asserted - as if that stuff was passé. If only.
That said, as Whitley talked and walked me through her vision and choices, her enthusiasm caught fire and I was often entranced, surprised, excited, and my senses were awakened. (I could see how the conscience would be, too.)
Eleven modern international artists will be showcased in assiduously chosen sites through the museum. It is another modish "intervention" where, instead of a dedicated gallery, thematic pieces infiltrate permanent collections to unsettle the calmness of the usual. I rarely find that this makes the kind of impact curators imagine it does. The East-West intervention at Tate Britain disappeared into itself; others turn into a puzzle and chase, the search for obscure meaning and connections leaving the soul bereft.
However, in this case some (not all) of the intruding artists will, I believe, have a daring visual dialogue with the venerated old residents. Will these interrogations "form a bridge between the safe and anodyne and the unspeakable and indescribable", as claimed in the guide notes? That remains to be seen.
There is also the question of how modern art responds to such a grave subject. One featured artist, Anissa-Jane, expresses some anxiety: "I don't believe there is a problem making contemporary art out of such a tragedy, as it creates interest and debate. I feel there is a possible mistrust of the unfamiliar, and there may be more of a problem expressing it."
Geoff Quilley of the National Maritime Museum considers another inherent difficulty: "The subject of slavery is shocking. There is always the problem that as soon as you aesthetise, you may reduce the gravity of what took place and the brutality of it." The subject may be unrepresentable without violation of collective memory. It can't be done, some say; not in our times, when art is expected to be light and airy and clever and individual and funny and lateral and perishable.
I don't share that view of the modern sensibility; I think it can be aroused and seek sublimation in the old and increasingly in the new. Look upon Turner's The Slave Ship (1840) and you find yourself there, witnessing the retributive storm. Beauty and wrath combine noisily, and you take away the hum in your head.
Or take another history - more recent and as evil - Nazism. In a meditation on the contemporary German artist Anselm Kiefer, Simon Schama writes: "He does the big embarrassing stuff, the stuff that matters: the epic slaughters of the world, the incineration of the planet, apocalypse then, apocalypse often; the fragile endurance of the sacred amid the cauterised ruins of the earth... He doesn't do weightless, or coyly self-effacing minimalism or gaudy showboating."
There are other vital debates that this anniversary has thrown up, and they will impact on the V&A and other museums. What are we marking? And why? Do you seek novel narratives or dig up the originals, lost to many generations? And is memorial art in a comfortable cul-de-sac?
Some Britons question this amnesiac nation, which has not looked into its own heart of darkness. The historian James Walvin throws a gentle rebuke; it will be seen as an impertinent challenge. "The story of slavery has slipped from Britain's memory," he says. "We must be wary of the triumphalism building up over the white abolitionists and hope for some contrition." Some hope, when Britons are preparing to bathe in warm virtue.
The journalist Gary Younge points out the fictions that have prevailed: "When it comes to constructing mythology, those things we feel the need to remember often take precedence over others we are desperate to forget... collective responsibility for our past successes soon subsides into individual flight from historical infamy." It is as if, after 200 years of freedom, South Africa were to choose to remember FW De Klerk's co-operation with Nelson Mandela without upsetting anyone by reminding them of the human suffering caused by apartheid. Or as if the liberation of Auschwitz (the good news) drives out the starved, dying, dead, blank-eyed camp inmates.
The academic Marcus Wood (white, middle-class, public-school educated) is stinging about presumptuous white fantasists who claim that "freedom" was given to black slaves. Freedom is not, he says, in the gift of any human, and the freed slave is not a jubilant child. However subversive art strives to be, the chosen anniversary is reactionary.
When it comes to the arguments about framing narratives, the writer Mike Phillips thinks the V&A's show "is rather intellectually vacuous. The display simply rehearses all the familiar themes; the cruelties of slavery, and the fact that Europe and white America profited from the trade. We've known all that for a long time. Ironically, most of the work is by African or American artists - once again avoiding the specific issue of what the slave trade signified in terms of the formation of British and European society."
He also wants to know why a black British curator was not given this job. "Far from being 'uncomfortable', this presentation comforts the public with the notion that all this happened long ago and far away," he says. Understand that Phillips is a competitor and his observations are not entirely neutral. He is a consultant to Tate Britain and has his own plans for what the anniversary should mean.
The year 1807 marks, for Phillips, a new climate of opinion in Britain and Europe. The French Revolution had carried ideas about liberty and freedom of speech throughout the world. At the same time, the successful revolution of slaves on the island of Haiti had set off a new debate about the viability of slavery and the nature of humanity. Tom Paine's The Rights of Man had become a rallying cry for European liberals and artists, and the transatlantic slave trade was the elephant in the room. The abolitionist argument defined Britain's moral and political identity, engaging leading artists and thinkers.
The publisher Joseph Johnson and the group of radical artists and writers who met in his bookshop engaged with those ideals, which led to the passing of the 1807 Parliamentary Act. Johnson's circle - and Blake's powerful engravings of tragic slaves - are to be the centrepiece of the Tate's remembrance of abolition.
The issue of memorial art is controversial and has been since the Holocaust. More recently, Rwanda raised similar * * concerns. Writing about Peter Eisenman's Memorial to Murdered Jews in Berlin (grey concrete blocks to disorientate and dehumanise), the art critic Jonathan Jones observed: "I couldn't see the myriad details of cruelty and hate and barbarity to which this monument abstractly refers. I couldn't help feeling that something is going on at this and other modern memorials that serves the needs and desires of the present and has nothing, really, to do either with making restitution for the past or ensuring that nothing comparable ever takes place again." Talk to angry young black men and you will hear these reservations, albeit couched in dazzling street language.
There is also a vague shame that slavery made them, and makes them still, into victims - hopeless people who can never break free. Yinka Shonibare MBE, one of the stars of Uncomfortable Truths, tells me: "I watched Roots again recently, and was as moved as the first time. But I don't want to reproduce that victimhood, or simply reflect slavery as absolutely horrible. That doesn't serve anyone well." I can feel him shrinking away from the emotionality, the pity of it all.
Keith Piper, an artist who caught the spirit of black Britons with his defiant work in the 1980s, adds: "Artists have always dealt with history. Contemporary artists should be no different, although fashion can sometimes be seen to dictate what is sufficiently 'cool' in terms of subject matter. Therefore, in a lot of cases, the overtly political is often squeezed out.
"But I don't think artists should in any way shy away from subject matter that could be seen as 'tragic'. What we do perhaps have to do is try to generate approaches to tragic or difficult subject matter that can perhaps propel the viewer beyond the horror/guilt moment." He has become less angry and more thoughtful, and I miss the early Piper who, with Donald Rodney, gave us The Next Turn of the Screw in the Eighties; violent yet always artistic images of black men dying in state custody, one of many legacies of slavery left to white gatekeepers.
These are vital debates and spirited disagreements - intellectually more vibrant than any I have heard previously. Whitley knows that the anniversary is arbitrary and problematic, but she believes (I do too) that the heat generated can turn on creative force and light.
The V&A exhibition guide is itself a startlingly effective object of art. Ultra-bright splashes of colour mark the route - silhouetted heads of black people, each subtly different, watery and lovely. Images of shackles and irons float on a page, disconnected, likely to invade your unconscious for a long time. They are by Christine Meisner, a white German artist whose larger works are even more insistent. In the sound and video installation Recovery, about the epic life of a freed slave (reflecting on leaving, moving, arriving, losing, unfinished business, unfinished cultural processes) she is making ceaseless journeys into the agonies of the black diaspora, thereby extraordinarily freeing herself. Her poignancy catches. She won't forget.
The African-American Fred Wilson, who represented the United States at the 2003 Venice Biennale, makes black things - gorgeous black things. In a New York Times interview, Wilson was candid about formal exhibitions: "Museums are good at making you forget the context. Every once in a while you have to step back and say, 'My God, what am I dealing with?' I want people to be blindsided, caught off guard."
So here is Regina Atra, a bejewelled crown on a cushion, copied from crowns worn by English kings, only black. Black blood, black gold, black oil, black mines, deaths, exploitation, beauty, tears. And yes, it does catch your eye and graze it but your heart doesn't pound with rage.
Then there is the theatrically satirical Shonibare MBE. (He insists on the honorific suffix: "One disturbs the Establishment by occupying its space.") His Sir Foster Cunliffe Playing is a headless archer in 18th-century gentleman's attire made of "African" textiles, which were Indonesian in design, mass-produced in Holland, appropriated by Africa. An inheritor of slave wealth, Cunliffe stands unabashed in the luxurious Norfolk House Music Room, getting up some stuffy noses, I am sure. Possibly, sensitive visitors will pick up from this work the pervasive presence of slavery in key institutions and in families of exceptional generational wealth. Most may only be very interested in the witty juxtaposition.
Anissa-Jane's exquisite handwork uses brown paper - a metaphor for skin - and forces it into luxurious day-coats favoured by slavers, fragile shackles for dainty ankles and chair covers stuffed with coffee beans. It is miraculously skilful and affecting. My daughter loves her creations. "I silently show," Anissa-Jane says, "how things can change, adapt, grow and strengthen in the conditions they are put through." Uncomfortable truths, though? It feels more like a feather teasing the cheek. Her work is mesmerising, wonderful yet glib; a bit like Maya Angelou's And Still I Rise homilies.
Michael Paul Britto's contribution is weirdly detached. The Brooklyn video and graffiti artist is showing his film of big black women ("slaves") dancing heavily to Britney Spears' "I'm a Slave 4 U". I get the bitter sarcasm, but is it art? Or is it profound enough art for this show? He responds as you might expect: "If viewers think I am trivialising slavery, that just lets me know they were affected by my work. I know where my heart was in that creation and I am cool with that."
Sorry, not good enough. It is a larky riposte, droll, bathos not pathos, and fails to unearth what Simon Schama describes as the "loam of memory". Perhaps this is the dilemma for most contemporary artists - their art crumbles under that much reality or responsibility. Shonibare MBE feels strongly that "it is always better when you add layers of complexity, so the terrible beauty is unpeeled. I'm not a polemicist artist. If you approach people aggressively they get defensive and no longer consider the work." But there's a difference between polemic art and art that carries the cry of humanity.
Marcus Wood introduced me to Kara Walker (not chosen by the V&A), the American muralist who works with paper cut-outs and light, and who does convey this cry of humanity. She covers entire walls with silhouetted slaver figures inflicting terrible wounds on black slaves - bestiality, castration, torture. Nothing is censored. Viewers find that their own shadows enter the scenes, implicating themselves. It's shattering, the spatial trap and the moral weight they carry.
This is what we need more of when contemplating slavery. Or a Guernica, to compel us to look upon the evil that still goes on the world over. It is "the horror, the horror" gone missing. I possess a copy of a handwritten inventory recording the value (currency unspecified) of slaves. Anthony and Natty are worth 150, Little Sampson 100, but John Boatswain and Pickup only 10. James is worth 00. Why? Was he close to death? Was Natty attractive, good sexual bait? The document does what "slaves" clapping to Britney Spears cannot. But then, I am not cool.
Millions of Britons are indeed cool and indifferent. These days on reality TV the young can cheerfully say "slavery was a good thing" (Channel 4, January 2007). Gary Younge rightly affirms: "Incisive art can shift your understanding of how the world works. But it doesn't come from nowhere. It needs a politically vibrant and curious society to produce it and receive it." Our culture has never been that receptive, and is even less so today to art exposing the evil of slavery.
A small number of resilient, serious artists still persevere. Two of the best will be at the V&A. In the John Madejski garden, expect a giant sculpture, a serpent shape by Romuald Hazoumé from Benin. He uses salvaged materials, in particular the plastic jerry cans used across Africa to carry water and other, lethal liquids that can explode and burn and kill. The sculpture reminds me of slave ships, of still passengers packed tight, in absolute symmetry. Today, it is economic slavery imprisoning people and the jerry cans carry that story.
The Ghanaian El Anatsui gets to the point where it hurts. Surviving Children is a tableau of figures made of aged driftwood; small, tall, all heights, ghosts lifted out from the bottom of the cold seas, naked, brittle - but look long enough and they breathe and whisper into your ear that the spirits of Africa do not rest. It is haunting, contemporary art of integrity, not a flighty fad or thing of political expediency. You reflect and lament, lament and reflect. For all the criticisms that can be made, this is remarkable "slave" art and for that we must be immensely grateful to Whitley and the V&A.
Additional reporting by William Roberts and Anne Giacomantonio
Uncomfortable Truths: The Shadow of Slave Trading on Contemporary Art & Design, Victoria and Albert Museum, London SW7 (020-7942 2000; www.vam.ac.uk), 20 February to 17 JuneReuse content