Whose lines are they anyway?: When the playwright becomes a character on stage, the game of hunt-the-authortakes on a new significance. Georgina Brown reports

'Theatre was an illuminant, sacred and indispensable. What is it now? Rows of seats for people to sit with folded arms,' says the playwright in Peter Shaffer's The Gift of the Gorgon. Or is it Shaffer's own view? The theatre has always been the ideal platform for writers to deliver a piece of their mind, and never more provocatively than when playwrights put playwrights on the stage. And in the West End, right now, playwrights are breaking out all over.

Edward Damson, idealist, egoist and extremist, stands at the centre of Shaffer's epic morality play, extravagantly pedalling his views about justice, revenge and the potential of theatre. In his spy-thriller, The School of Night, Peter Whelan presents an alternative version of the events leading to Christopher Marlowe's death, aged 29, from a stab wound, and can't resist placing two dramatic aces - Marlowe and Shakespeare - on stage together to debate the writer's purpose. In Martin Crimp's savage New York-set satire The Treatment, a once-acclaimed playwright is punished for his voyeurism in a particularly brutal manner, and it is this, and not his work, for which he becomes famous. In Trelawney of The Wells, Tom Wrench's pain and heartache is very much a self-portrait by Pinero of his struggle in a milieu in which he knew he was gifted but getting nowhere.

None of the plays offers a paranoid navel-gazer's tour of the writer's psyche in the way that Peter Nichols' A Piece of My Mind and Tom Kempinski's Separation examined blocked writers (the former whiningly, the latter winningly). But in all of them, consciously or not, the playwrights spill pretty personal beans. John Caird, director of the National Theatre's Trelawney, believes that: 'Most playwrights will at some time in their career want to dramatise the creative urge they find in themselves, though some chose to disguise themselves - like Shakespeare in The Tempest and Ibsen in The Master Builder. Playwrights soak up whatever is going on around them. Inevitably the more successful they get, the more time they spend in the professional theatre, so the more likely it is that their terms of reference will be a theatre-play of some sort.'

A theatre-play involving a playwright invariably attracts accusations of narcissism, arrogance and pretentiousness. Pinero, in this case, is reasonably objective. As Caird explains: 'He had become a success by the time he wrote Trelawney and it's also a portrait of the theatrical world just before he began working in it, when grand gesture and pantomime gives way to naturalism. No one wants to listen to a playwright harping on about how difficult the job is. It is difficult, but it's not the writing that's hard, it's the powerlessness and the dependence on producers and directors.'

For Peter Shaffer, putting a playwright on stage was a way of overcoming a practical problem. 'I love the idea of extending the grammar of the theatre and I wanted to write a play involving several time schemes, several locations, and to write a naturalistic play which would have incursions from mythic Greece, sixth-century Byzantium and Cromwellian England and make it a seamless fabric. The only way was to use letters or plays. If I'd done the same thing with a novelist, I wouldn't have known how to make it theatrical.' He was, however, aware of the dangers. 'This is a treacherous area and I didn't want to appear vainglorious, but I had to bite the bullet. I knew that the automatic assumption would be that I'm being autobiographical - and in the domestic areas this play is my least autobiographical. If I'd wanted to be autobiographical the last thing I'd do is put a playwright on the stage.'

Nevertheless, Shaffer's preoccupation with the 'duty' of the playwright, is one of many themes of the play. Edward Damson's belief that 'it's the playwright's duty to appal. Tear an audience out of moral catalepsy' is tempered by his wife's belief that 'it's a playwright's duty to be fair. To his subject, and its complexity . . .' But Shaffer undoubtedly shares many of Damson's views about theatre's unique power to astound and transform. 'It's a playwright's duty to be theatrical,' Shaffer insists. 'That's often used as a term of abuse and I deplore that. No painter is attacked for being painterly, no musician is attacked for being musical, but a playwright is attacked for doing his job.'

In The Gift of the Gorgon, the playwright's moral responsibility also comes under scrutiny. Damson's play exhorting the audience to 'take the way of blood' is his attempt to reclaim theatre's 'moral power'. His wife calls it evil. 'The moral responsibility of a playwright,' says Shaffer, 'is to engage in complex human encounters and still entertain (another dirty word these days). When Damson talks about the public's 'thirst for right', that's a statement I do believe in. In a situation like the Warrington bombing, the initial rage gives way to more moderated reflection - the battle between rage and those feelings is the real substance of this play. But you've got to hold people in their seats without being neutral. One of the biggest problems is to make a climax, a finale, that will hold theatrically when you are dealing with an irresolvable argument about what is right - you must have the aspect of resolution, of a resting point made out of restlessness. The play must end, but the debate must go on and on.'

Martin Crimp disputes the notion of moral responsibility. 'Wilde said morality is just a colour that he uses to raise an issue, engage and focus our attention. As a writer I have a satirical impulse, which is not the same as being a moralist - a moralist doesn't make you laugh.' Crimp was loathe to place a playwright anywhere but in the margins of his play. In his initial draft for the opening scene, the person being interviewed about a violent attack was a writer. 'I was excited by the scene but not by a writer. It's like someone else standing on the same patch of ground as you are, inhabiting your space. So I changed it. As soon as the writer went away I was liberated.' Crimp admits, however, that Clifford (the playwright) does reflect something of himself. 'He represents a fear of being abandoned, of no longer having the contacts or the people interested in you. It's easy for a writer's life to become his or her whole life. You can be left at the end with nothing but emptiness. He's what I don't want to become.'

Peter Whelan loved the idea of writing about another writer. 'Whether you are doing it with a biro or a computer, you're doing exactly the same thing that they were doing, experiencing the same sensations.' Having investigated Marlowe's life, he decided that since there were only five theatres in London at the time Marlowe was working, he was bound to know Shakespeare, his fellow-dramatist. 'I was conscious of dealing with two mountain peaks - it's rather a cheeky thing to do.' And once he'd got them on stage together he couldn't avoid a discussion about their art. Marlowe claims that Shakespeare 'holds up his mirror to humanity - I look behind the mirror'. Shakespeare, a watchful genius, meanwhile, regards the artist as a semi-divine medium, denying there is something called 'the writer's purpose' you can separate from his art. Whelan is on Shakespeare's side. 'A play is more like a release of forces, rather than something with a purpose,' he says. 'I'm not writing in order to convert people to something.'

He does confess, though, to an twinge of narcissism in putting a playwright on the stage. 'As a playwright you know you are light years away from these writers - Shakespeare has an organic sense of a play having a life of its own; Marlowe burns a firebrand carrying powerful ideas. But like a mariner, the more urgent need is to position yourself by your relationship with others. And there's arrogance too, but a playwright must have a belief in himself to think what he has to say is worth people listening to.'