THEATRE / Viler than violence: Out of sight, but all in the mind. Paul Taylor cuts to the quick of the most blood-chilling, gut-spilling dramas on stage today

Tamora, Queen of the Goths, is the kind of woman who could eat a man for breakfast; but she winds up - thanks to the culinary vengeance of Titus Andronicus - consuming her own sons for dinner at a feast that might be said to take the biscuit for bad taste. If the demotic descendant of Shakespeare's Roman revenger is the demon barber, Sweeney Todd, whose victims become the filling for his accomplice Mrs Lovett's meat pies ('Shepherd's pie peppered / With actual shepherd / on top' as Sondheim's jokey lyric puts it), then the gruesome forebear of both works - and the reason why Tamora's emetic repast is often referred to as a Thyestean banquet - is Thyestes by the Roman dramatist, Seneca.

A play in which the unwitting title character is tricked into devouring his own sons' flesh at dinner by Atreus, his warped score-settling brother, it's a theatrical rarity that is now reclaimed in a new version by Caryl Churchill opening tomorrow night at the Royal Court Theatre Upstairs. The publicity for James Macdonald's intriguing production (which was last week unveiled in Manchester City of Drama) is keen to stress the brutality of the piece, suggesting that Thyestes is the ancestor not just of Hamlet but of films like Reservoir Dogs.

Given this claim, and the fact that the production of King Lear just opened at the Barbican offers a disturbingly new slant on that play's atrocities, it seems a timely moment to reconsider the question of stage violence in both its technical and moral aspects. How can it be conveyed theatrically in a way that manages to pierce through our layers of television- and film-fostered desensitisation, avoiding cheap thrills, keeping control of the sick comedy that inevitably hovers round this area, and putting us in touch with the wider implications of the violence for all concerned, including ourselves as witnesses to it?

In one respect, it's ironic that the hype for Thyestes should fix on its gory savagery. It's true that Seneca's works may well have contributed to the taste for violence on the Elizabethan and Jacobean stage. But the likelihood is that in Seneca's own Neronian times, when you could gloat over spectacles of far-from-fictive butchery in the amphitheatres, these highly rhetorical dramas were performed purely as recital pieces at private gatherings, the Greek practice of keeping the violence off stage thereby pushed to a new extreme.

But that's a convention which some modern directors have shown to be liberating rather than limiting. There has, for example, been no more shattering portrayal of savage murder in recent years than that moment in Deborah Warner's Electra when, obeying the letter of the off- stage rule but brilliantly violating its spirit, Clytemnestra's murder was presented as the cacophonous clash of screaming flesh against the metal doors that had just slid shut behind her, and then as the sudden sickening flow of red in the clear water gulley dividing the palace yard. Called on to fill in the details of the horror, your imagination felt at once flattered, uncomfortable, and faintly compromised, which is a more salutary sensation for it than feeling numbly de trop as it does when faced with the high-tech literal- mindedness of many a violent movie.

In his production of Thyestes, Macdonald plays around differently with the same convention, bringing the off-stage world on-stage via the eerie means of video monitors jolted to life or caused to switch image by the unnerving sounds of crashing that punctuate the dank, sinister background noise of pouring liquids.

These monitors have several dramatic functions. By intimating a surveillance world, they can give a powerful sense of the trap Thyestes is walking into. They can also project what is in the mind's eye of the protagonists, as when, after the feast, Thyestes begins, almost literally, to get wind of what has happened and the image of the candle-lit dinner table covered with the remains of his sons goes into a sick swaying motion on the screen. And, last but not least, they serve as accusing symbols of our modern voyeuristic fascination with violence, and of our dislocation from it. The monitors purposely keep you peering at matters that remain, teasingly, in some degree of murk.

Thyestes is a play which wonders volubly whether there are any limits to the cruelty human beings will inflict on each other. It's a speculation from which the drama derives both its deepest tragedy and its blackest comedy. For if the atrocity at its centre throws the heavens in turmoil, turning day to night, it also proves, ludicrously, to be a big let-down for Kevin McMonagle's beady, laid-back Atreus. Circling the stricken brother so as not to miss a second of his reaction to the staggered revelations and pointed, tasteless innuendo (Thyestes, quaffing his sons' blood, is alerted to its being a 'family wine'), Atreus starts to succumb to darkly farcical dissatisfaction.

It's not enough, he decides, to have butchered one's nephews, roasted them on spits, and served them up to their father. To content him properly, he now claims, Thyestes and his boys would have had to be conscious of what was happening during the cannibalistic banquet, an impossible feat. With boundless perverted desire bumping haplessly against the limits of logic, the play imparts a strong sense of the futility of violent revenge, heightened in this production by a reversal of expectations at the end. Of the two, it is Atreus who looks to be coming unravelled.

The effects of violence on the violent cannot be overlooked by any responsible play. Lately, though, theatre directors have been at pains to examine the corrupting effects of a violent society on its virtuous members. Frantic to impose some logical pattern on the senseless and arbitrary moral universe of King Lear, Kenneth Branagh's Edgar rounded off their duel by savagely blinding his bastard brother, an act grimly in line with his desperate rationalisation of their father's suffering: 'That dark and vicious place where thee he got / Cost him his eyes'. More worrying because it erupts more randomly, the violence of Simon Russell Beale's Edgar in the current RSC Lear is first furiously visited on the odious Oswald, whose face he beats to a pulp. This is not a production that pretends the virtuous necessarily come through uncontaminated.

On the other hand, it does not insist that contamination is inevitable. Edward Bond - who once announced, 'I write about violence as naturally as Jane Austen wrote about manners' - dismisses as 'a feudal myth' the incident in Lear where Cornwall's servant makes a sudden courageous gesture of protest during the blinding of Gloucester. He regards it as a sentimentality.

With its hideous rapes, mutilations, coldly clinical blindings, ghosts and shootings, Bond's revisionist Lear is more reminiscent of Titus Andronicus on the atrocity-count. Yet nothing in it sickens the stomach quite as much as the dramatist's doctrinaire insistence, through the figure of Soldier A, that a man in the employ of authority would be incapable by economic necessity of anything but a brisk, businesslike attitude to the human being with the ripped-out tongue and ears deafened by knitting needles he has just robustly tortured. When one of Lear's daughters yells 'Beg for his life]', it takes the soldier a rum second or two to grasp that she wants him to put in a pretend plea so as to heighten her kinkily sadistic pleasure in the barbarism.

A programmatic refutation of Cornwall's servant, Soldier A is such a patronised puppet of the work's thesis (that violence is not innate in people, but a reaction to the institutionalised violence of oppression) that you feel he is living as much under Bond's tyranny as the tyranny of the times. 'Walking offal] Don't blame me, I've got a job t'do,' the soldier tells the poor released wretch. 'If we was fightin' again t'morra I could end up envyin' you any time . . .' The contrived matter-of-factness of the speech reminds you that it's not just through the physical ordeals in the plot that dramatists can do injury to their characters, or to our sense of the complex operations of violence.

(Photographs omitted)