George Orwell, in his essay Decline of the English Murder, pictured a typical British 20th-century Sunday. On a snoozy afternoon, with the kids out of the house, you put on your glasses to read the News of the World. You are digesting a heavy lunch, the fire is lit, everything is cosy.

"In these blissful circumstances, what is it that you want to read about?

Naturally, about a murder."

Almost everything about Orwell's image of the typical newspaper reader has changed. The British family is a lot less likely to gather for a roast beef lunch, even less likely to light a coal fire. Sending out the children for a nice long walk sounds like a recipe for some kind of disaster. The News of the World no longer exists. Yet people still like to read about – and look at pictures of – murder and grisly crime.

This week the website of the News of the World's sister paper the Sun published this photograph of the corpse of Rudy Eugene taken shortly after police shot him dead in Miami on 26 May. Eugene was caught in the act of biting off a homeless man's face: after refusing to stop the attack, he was killed. His victim Ronald Poppo survived and is now undergoing a long course of surgery to reconstruct his face and try to save part of his sight.

These are the facts, but as the release of this picture and its appearance on news sites around the world – in Britain the Mail also used it – reveals, public fascination with the case goes far beyond the usual. A crime with no obvious implications for general problems of law or society – that was, unlike the atrocities nostalgically evoked by Orwell, not even a murder – is still getting attention weeks after it took place. The victim has become a celebrity while his dead attacker is considered so beyond the human pale that news media break a taboo and show his dead body.

This happened too in the case of Muammar Gaddafi, whose bloodstained corpse became world news. In both cases the implication is that the dead person is somehow less than human – a monster.

The rights or wrongs of showing this picture do not interest me so much as the compulsion to look. I find it disgusting, repulsive, but also interesting. The real lure of the picture as with all the previous images released of this strange crime is the bloody glimpse of Ronald Poppo's head: the tragic sight of a cannibal's living victim.

I would argue that it is completely natural to want to – briefly – look at this, because the cannibal myth is central to human culture. If anything can be said to be "hardwired" into the human imagination, it is the fear and perhaps, at some deep level, the memory of cannibalism.

Human beings have eaten one another from necessity and for religious or magical purposes at various points in history and prehistory. Cannibalism was practised by stone age people who used the caves of Cheddar Gorge. It resurfaced during the famine in Russia in 1920-21. Shipwreck survivors have been driven to it – cannibalism is the hidden horror that haunts Gericault's painting of people cast adrift on a desolate sea, The Raft of the Medusa. Yet for every recorded case of cannibalism, there are far more images of it that can be called mythic and fantastical.

The first European travellers to the New World brought back tales of cannibals. The sensational descriptions of their supposed rituals in Amerigo Vespucci's early 16th century writings were calculated to feed European imaginations with horrible pictures of otherness, of "inhuman" behaviour. European folk beliefs feature human-like creatures that feed on human flesh: the werewolf and vampire are supernatural cannibals. All this suggest that the difference between those who eat people and those who don't is quite basic to our definition of the human. In colonial times, this turned into coarse racist fantasy, The medieval poet Dante saw deeper: for him, the human in us is fragile, and can be overwhelmed by circumstance. In his Inferno he tells the tale of Count Ugolino, imprisoned with his small sons in a tower in Pisa, shut away in a dungeon in the dark and left to starve. His children died first. Blind from hunger, he fed on them.

When Dante first sees Ugolino and the tormentor who imprisoned him in Hell, their two heads stick out of a frozen lake: one chews the other, for all eternity. It is an image not so very different from the reality that confronted the Miami police officers on 26 May.

It is not wrong either to show, or behold, these images. It is an inevitable response to a phenomenon that has shaped what it is to be human, and what it is to be monstrous. What is a monster? Someone or something that wants to eat us.

And yet, the fascination is misplaced. A few days ago it was discovered that Rudy Eugene had no human flesh in his stomach. Whatever he was doing was not, after all, cannibalism. He was neither myth nor monster but a man who died, and it is time for him to rest in peace.

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