This is an edited version of last night's talk on Radio 4, which will be repeated at 9.30pm this Saturday on Radio 3. The last lecture, 'Home: Our Famous Island Race', will be published next Thursday in the 'Independent'

In 1844 the great Victorian art historian and critic John Ruskin was given a Turner painting by his father, as a reward for the success of the first volume of his art criticism, Modern Painters, and it was chosen because it had inspired Ruskin to write: 'I believe, if I were reduced to rest Turner's immortality upon any single work, I should choose this.'

Ruskin kept the painting for nearly 25 years, until he found the subject, he said, too painful, and had to part with it. Before that, he had evoked his Turner in one of his most gorgeous hymns to the sublime:

. . . purple and blue, the lurid shadows of the hollow breakers are cast upon the mist of night, which gathers cold and low, advancing like the shadow of death upon the guilty ship as it labours amidst the lightning of the sea, its thin masts written upon the sky in lines of blood, girded with condemnation in that fearful hue which signs the sky with horror, and mixes its flowing flood with the sunlight, and, cast far along the desolate heave of the sepulchral waves, incarnadines the multitudinous sea.

But in all this cascade of praise, Ruskin never tackled the subject of the painting at all. The work (now in the Museum of Fine Arts, Boston) is usually known as The Slave Ship, but its full title is 'Slavers throwing overboard the dead and dying - Typhon coming on'. In the foreground, in the welter, the drowning slaves are just visible, while shoals of sea monsters are racing towards them to gorge on them.

Turner had read a history of the abolition of slavery and found that in 1783 the owners and captain of a ship called the Zong were charged with fraud by an insurance company. They had claimed for the deaths of a cargo of slaves by drowning. The policy didn't cover death from illness, and so the captain had thrown overboard, on three successive days, 122 sick men and women in order to collect the money for them. The insurance company proved its case. No further criminal proceedings, however, were instituted by the courts against the Zong's masters.

Turner painted this extraordinary synthesis of the trade's horror seven years after the abolition of slavery. His approach sublimates the theme: Turner didn't paint the drowning as people, but as fragments. One leg, shackled at the ankle, breaks the surface of the seething water in the foreground; alongside, pairs of hands are raised making imploring gestures which rhyme - with ghastly irony - the fins of many fish cresting the waves as they arrive for the feast. Huge links of chain thrash in the water, rather implausibly, but marking the position of submerged bodies below. Turner gives us just the one black leg, the waving hands, and the great glassy visage and gaping maw of pink sea monsters.

Turner's whiskered, jowly and pink sea monsters moving in to feed on flesh stand for the well-fed but still hungry, pink, whiskery merchants who trade in Africans. He identifies himself with them.

Something else is also hinted by the imagery of the marine feast in the painting: an allusion to the deep-seated racial myth of cannibalism, to the much repeated notion that the people who were sold as slaves were barbarians. And the most laconic sign of the barbarian had been, since classical times, cannibalism. Those fish preying on human flesh, representing the slave traders, bring to mind the question put by the French essayist Michel de Montaigne three hundred years earlier. He asked, who are the barbarians: Christians who hanged, drew and quartered their fellows, tortured them with irons and burnt them alive at the stake, or savages who waited till their victims were dead before they cooked them? Turner's painting raises the question: who are the cannibals now, us or them?

Stories of cannibalism, like rape, weren't always connected to myths about barbarians, or even about monstrousness. Control of the processes of consumption confers great power, as we know from the priests officiating at the Christian Mass. The faithful eat the body and drink the blood of Christ in the sacrament of the Eucharist, and this repeated miracle of transubstantiation possibly meets a fundamental human desire to incorporate the object of passion, of wonder, worship, dread, of love, too. Every time a mother squeezes her child and murmurs, 'Mmm, you're so good I'm going to eat you,' she is using the same imagery of union, of total commingling intimacy; every time lovers pretend to gnaw and bite each other, they are tapping the same metaphor.

A slippage occurs in these well- named acts of communion - between actual and symbolic consumption of human flesh - and the arguments about the real presence of Jesus's body and blood have entangled further the confusion about the reality of cannibal acts.

Cannibalism isn't, of course, a peculiarly Christian theme; it is common in classical myth, where it is an activity of the gods, on the whole, like rape. Zeus, king of all the gods, survives only because his mother, Rhea, foils his father's plan to eat him, as he has eaten all his elder brothers and sisters. She wraps up a baby-shaped stone in swaddling bands and Cronus swallows it happily; Cronus had been told that one of his sons would supplant him, hence his desire to rid himself of them. But his method of doing so later casts him in the maternal part: for Zeus, when he grows up, gives his father a drug which makes him vomit up alive all the other children in his body. In this way, the famous Olympians - Hera, Demeter, Hades, Hestia, Poseidon - re-enter the world, twice born of their father, begotten and brought forth.

In myth, cannibalism often occurs alongside incest; both demonstrate the gods' outrageous flouting of human laws. Cronus commits one crime against human order by eating his children, and another because they are his by his sister Rhea. Later, Zeus and Hera, as well as several other marriages and unions among the Olympians, would continue the custom. Incest figures as a form of metaphorical cannibalism: eating your own. It also conveys a terrible incapacity to recognise your own: cannibals fail to see their prey as their kind, and this is an act that in effect exiles them from humanity. Likewise, the incestuous father of myth and fairy-tale fails to recognise his proper relation to his kin, and similarly becomes something less than a father or a human being. Both acts also relate to fears and longings in deeper ways: both acts offer an image of the transgressive acts of incorporating closeness, of failure to respect boundaries; in both, the perpetrator oversteps the bounds of kinship.

Cannibalism comes in four permutations, broadly speaking: raw or cooked, your own flesh or your enemies. The Ogre in 'Jack the Giant-killer', like many other monsters of fairy-tale, dines on humans after the famous refrain:

Fee, fie, fo, fum,

I smell the blood of an Englishman,

Be he alive or be he dead,

I'll grind his bones to make my bread.

He ends up tricked into eating his own children. Travelling back to England once, I was sitting next to a cheerful Cornishman; as we flew in over Devon, he remarked with a smile, 'Oh, you have to tread carefully with them, they eat their young down there.'

But the first image that springs to most people's minds when they hear the word cannibal isn't a Greek god, or a fairy-tale ogre, or a Devon family. I was brought up for some of my childhood in Belgium, surrounded by images of the then colony - the Congo, as Zaire was then known; among them were many jokes about 'long pig', and much talk of missionaries trussed and spitted or standing in stewpots over cooking fires, as patient as Christian martyrs in the arena. Some of this was facetious, but at the same time, it wasn't questioned - as it isn't in Evelyn Waugh's Black Mischief either. Behind these preconceptions lies a history.

In the age of the conquistadores, the word 'cannibal' was adopted from the people of 'Carib', in whom Columbus confidently recognised the famed anthropophagi, or man-eaters, of myth. Like the gold which he was certain was always round the next headland, it was always the tribe over the next ridge who were feasting on human flesh. Columbus left the myth of cannibalism thriving, but no account of the practice.

By the 15th century, the sign of being a barbarian, rather than an ogre, was a preference for cooked rather than raw human flesh. The word 'barbecue' is indeed one of the words, like 'hammock', borrowed into English from the language of the Taino people of the Americas. Though the Taino themselves were famed for their gentleness, the evolution of the word 'Carib' into 'cannibal' conveys how Indians in the Caribbean came to be considered eaters of human flesh, never happy unless they were roasting the spiced joints of their victims on these ingenious grills over open fires. The name of Shakespeare's 'salvage and deformed slave', Caliban, in The Tempest, echoes this derivation.

Eye-witness accounts have proved highly elusive, believers in cannibalism taking the view that ipso facto nobody survived to tell the tale, sceptics arguing that the fantasy recurs in almost all people's insults against aliens: Christians were obvious candidates for the accusation during the Roman persecutions; in the Middle Ages, pogroms were unleashed against Jews charged with eating Christian children; the same outrage was considered routine among witches (they needed to render down baby fat to make their flying ointment - only then could they take off on broomsticks to the Sabbath). Thus one excessive fantasy becomes necessary to another in the mad but lucid circuitry of the imagination. In Australia, the Aborigines were credited with a particular taste for Chinese; rumours of their manhunts are still being repeated, with no evidence whatsoever. The gastronomy of cannibals, their culinary procedures and table manners, were similarly envisaged in precise detail; indeed, as precisely as the Black Masses of devil-worshippers were rumoured to reproduce Christian solemnities in ghastly inversion.

It would be silly to pretend that in the violence of conquest nobody was ever barbarically dismembered, or butchered or hideously dealt with after death; there is evidence among some tribes in the Americas for ritual ingestion of human remains at funerary feasts, as well as the bloodthirsty human sacrifices of the Aztecs. But empirical support for cannibalism as a routine form of sustenance has never been found; that it was a needed source of protein, as one historian suggests, is simply fanciful. Yet the idea refuses to go away. A BBC series on the Empire included an introduction to the Caribbean which said, 'When the British first arrived . . . the necklace of lush tropical islands . . . was still largely the preserve of cannibals.' This was 1972]

It is really only in the last decade that historical study has established how deeply fantasy has shaped the story and the chronicles of conquest. Cannibalism helped to justify the presence of the invader, the settler, the trader bringing civilisation. If my enemies are like me, how can I go on feeling enmity against them?

Cannibalism marks its practitioners as throwbacks, barbarians, stone-age men, yet the conqueror's imagery can betray that he is himself the devourer, like the slavers throwing overboard the dead and dying. Trophy-hunting isn't the province of savages: the cabinets of curiosities of the early modern connoisseur were filled with grisly spoils. The phrase 'I'll have your guts for garters' catches the universal humanity of the impulse.

Cannibalism is used to define the alien, but actually mirrors the speaker. By tarring the savage with the horror of cannibalism, settlers, explorers, colonisers could vindicate their own violence. It's a psychological manoeuvre of great effectiveness.

Seeing the conquered as brute barbarians helped the confidence of the first empire-builders. Early on, however, there were dissenting voices. Montaigne, who had reminded his readers that they were as savage as their victims, lamented the plundering of the New World in a great threnody:

. . . so many goodly citties ransacked and razed; so many nations destroyed and made desolate; so (many) infinite millions (sic) of harmelesse peoples of all sexes, stages and ages, massacred, ravaged and put to the sword; and the richest, the fairest and the best part of the world topsiturvied, ruined and defaced for the traffick in Pearles and Pepper. Oh mechanical victories, oh base conquest]

Montaigne's passionate defence of the Indians seems to have influenced Shakespeare's attitude in The Tempest. The play was inspired by the miraculous survival of a group of early colonists after a shipwreck in the Caribbean; and Shakespeare follows the reports of first contacts when he describes how Caliban greets the mariners kindly and helps them by gathering unfamiliar food and fishing for them. Like the Indians whom buccaneers traded with - Captain Roger North in Guyana and Walter Raleigh in Virginia - Caliban shows the new arrivals, Prospero and his daughter, 'the wonders of the isle'. In spite of the overtones of Caliban's name, Shakespeare doesn't represent his 'monster' as a consumer of human flesh at all, but rather of 'pig-nuts' and 'filberts'. But his portrait is ambiguous, as the amount and variety of stagings and interpretations show. He does describe him as a savage, and 'a freckled whelp, hag-born', who doesn't know language before Prospero teaches him and has since learnt only how to curse; nevertheless, Caliban is given some of the most lyrical and anguished passages of poetry in the play.

This contradiction at the heart of the characterisation has turned Caliban into a mythic figure beyond the confines of The Tempest itself, who combines in himself all the ambiguities of the beast symbol, of the call of the wild. He has consequently become a key symbol in the history of colonialism, and of its attendant ills, including racism.

Caliban has been played over the years as a kind of fish, or a manatee, as a wild man like Orson the bear-cub, as a green man, a classical Satyr, a half-naked Indian, or, as one actor's wife commented, 'half-monkey, half-coconut'. In the post-war period, when the various empires were beginning to come to a kind of end, the figure of the dispossessed native slave inspires new interpretations - from Caliban's point of view. W H Auden, in The Sea and the Mirror of 1944, glimpsed how Caliban might refuse to be the subject of his masters' serene providence, how the relations of dominance and economic power might crack. The colonial psychologist Octave Mannoni pioneered in 1950 the explicit interpretation of Caliban as a colonial subject, raging impotently against his oppression, unable to act to articulate his freedom or his rights, caught in a vicious spiral of powerlessness and petty retaliation. Fernandez Retamar, in a subsequent impassioned essay, focused on Caliban's blackness, and the poet Aime Cesaire, the long-time mayor of Fort-de-France in Martinique, gave a Marxist spin to this idea in 1960, with a rhapsodic, whirling version of The Tempest in which Caliban becomes a freedom fighter for the inhabitants of the island, and like a Toussaint l'Ouverture, rises against the coloniser, Prospero.

Caliban's role touches one of the most sensitive areas in contemporary race relations; he reveals once again how the perception of civilisation and barbarism so often turns on the question of alliance and family. The exchange between Prospero and Caliban, when Prospero gives the reasons for his rejection of Caliban, is highly revealing.


I have us'd thee,

Filth as thou art, with human care; and lodg'd thee

In mine own cell, till thou didst seek to violate

The honour of my child . . .

Caliban howls in reply:

O ho, O ho] woulds't it had been done]

Thou didst prevent me; I had peopled else

This isle with Calibans.

Caliban's segregation as a monster beyond the pale takes place only after he has tried to 'violate' Miranda. Before that, he had lived with them, as if he were one of the family.

But one rape could hardly have engendered a population for the island - these lines express those old fears of heterodox misalliance; they also hint at a kind of incest between Caliban as Prospero's foster child and Miranda, Prospero's daughter. There is even a hint that Prospero may be more than a foster father when he says of Caliban, at the end, 'This thing of darkness I acknowledge mine.' Caliban's threat conveys the not unconnected fear of hybridisation: the monster will produce monstrous progeny.

These same fantasies continue in popular attitudes to black immigration and to intermarriage between races. Caliban's threat of proliferation continues to resonate: when people are asked to give the size of the black population in Britain, they sometimes put it as high as a quarter of the total. The true figure is around a twentieth.

The Tempest concludes with the restoration of harmony, the obedient love of Miranda and Ferdinand, and Caliban's promise that he'll 'be wise hereafter and sue for grace', a reference to his possible baptism.

It is interesting to note that in 1611, around the time Shakespeare was writing the play, the son of a prince from Guinea called Caddi-biah - another echo - was christened in the church of St Mildred Poultry in the City of London, not far from the Rose and Globe theatres and the inns that Shakespeare frequented. The boy had been entrusted to one John Davies, of the English ship the Abigail, by his father. Or so the register related.

Even if the coincidence is meaningless, the presence of the Christian, African youth in London upsets received ideas about the history of migration; it puts paid to the prevalent opinion that black people only arrived in Britain with the waves of workers invited after the war. There are entries in parish registers from the 17th century of births and deaths of children born to English and African couples; while abroad, in the new possessions, intermarriage was far more common than has been admitted. Not all converted, however: the brother-in-law of the famous princess of the Algonquin tribe, Pocahontas, for example, refused to be baptised, preferring, a contemporary reported, 'to sing and dance his diabolicall measures'.

Only office buildings, gleaming in glass and steel, now rise around the area where the Church of St Mildred Poultry stood. The disappearance of so many of the old City buildings has been followed by the disappearance of most of the residents. This scattering in itself has carried off the memory of an earlier time - including the recollection of the earliest black Englishmen and women. Yet far less historically attested tales of cannibals practising savage rites in some distant place cling on about cannibals practising savage rites.

In this context, it is interesting to discover that the Mandingo, a people of Guinea, ascribe the birth of narrative itself to cannibalism. But in this story, cannibalism is an act of a rather different order to the crimes in Western story-telling: a man dying of hunger tells the friend with whom he is travelling that he can go no further. His friend tells him to wait, and he will bring him something to eat. He disappears, and soon returns with a steaming dish which saves the dying man's life. Many years later the good samaritan reveals that he hadn't shot a deer, or a bird, or even an elephant for his dying friend all those many long years ago. No, he had cut the flesh from his own thigh and cooked it. When the recipient hears this, he replies, 'The memory of your kindness will never be lost, I will tell this story to sing your praises all my life, and pass it on to my descendants, and they will continue.' In this way, the griot, the storyteller of West African society, came about. The story today, told by the writer Tierno, also wittily inverts the usual Western attitudes to barbarians - the act seen as defining their brutal inhumanity becomes proof instead of an excessive altruism.

Cannibalism has taken place and has been - and is - very widely and deeply experienced. In the imagination. It has been practised, in my view, very rarely, in extremis by individuals. But the fantasy lay on the surface of the minds of the explorers from Europe, from centuries of myth-making, an expression of deep desires and terrors, when they reached those places they called the Indies.

That imagery of forbidden ingestion masked other powerful longings and fears - about mingling and hybridity, about losing definition, about swallowing and being swallowed - fears about a future loss of identity, about the changes that history itself brings.

But new voices are being raised to confront this legacy. The terrible story that inspired Turner to paint The Slave Ship has continued to resonate; it has that extreme, cautionary quality of myth. Barry Unsworth, in his novel Sacred Hunger, developed the Zong's crime: and the Guyanese-born poet David Dabydeen has written a long lyric sequence, called Turner (published last month by Jonathan Cape), which, unlike the artist, unlike Ruskin, gives a voice to one of the drowned slaves in the painting and imagines the atrocity from his point of view. The drowned slave struggles to dream of the future he has lost and still wants to make, but his memories oppress him:

no noise

Comes from my mouth, no lamentation

As I fall towards the sea, my breath held

In shock until the waters quell me.

Struggle came only after death, the flush

Of betrayal, and hate hardening my body

Like cork, buoying me when I should have sunk . . .

but . . . my face was rooted

In the ground of memory, a ground


By herds of foreign men who swallow all its fruit

And leave a trail of dung for flies

To colonise; a tongueless earth, bereft

Of song except for the idiot witter

Of wind through a dead wood.

Dabydeen is using his poem to repair that loss, he is putting his song in the place of his subject's imposed silence. From submersion, from engulfment, the images can return, the drowned can rise, the devoured can be pieced together and the cannibalised past be heard, telling its stories.

The full text of the six lectures will be published by Vintage on 21 April at pounds 4.99.

Illustrations: Hulton Deutsch