Edinburgh Festival Day 1: The Greeks have a word for it: Read the signs in the work of Peter Sellars and you'll see actions speak louder than words. By Mark Pappenheim

IT IS typical of Peter Sellars' approach to theatre that he should give a leading role in his new adaptation of Aeschylus' The Persians to a deaf actor performing entirely in sign language. It is also somewhat surprising for a director best known here for his operatic work - his televised Mozart / Da Ponte trilogy, with a Cos set in 'Despina's Diner' and a Figaro at the top of the Trump Tower; his dialogue-free Glyndebourne Magic Flute, re-enacted on (and under) an LA freeway; and, most controversially of all, his two news-driven collaborations with the post-Minimalist composer John Adams, the 1987 diplomatic comedy Nixon in China (brought to Edinburgh in 1988) and the 1991 terrorist tragedy The Death of Klinghoffer (co-produced by Glyndebourne but yet to be seen in this country).

But then, Sellars suspects we set too much store by words. 'Ninety per cent of our communication is non-verbal,' he maintains. 'We vastly overrate words, basically because it suits our legal purposes.' For him, Howie Seago's silent signing as the ghostly Darius only emphasises the physicality of Greek tragedy - both sung and danced, as well as declaimed - that made it the model for modern opera. 'Deaf or not,' he says, 'he's simply one of the great actors, with an added commitment to communication that he just does not take for granted.' And putting a deaf actor in front of a hearing audience underlines what is, for him, a key aim of theatre - the search for common understanding: 'How is it possible for one person to understand another, and where do the misunderstandings occur?'

The earliest surviving Greek tragedy and the first historical drama, The Persians is also the first play to make the ultimate leap of sympathy - into the mind of the enemy. First staged in 472 BC, only eight years after the abortive Persian invasion of Greece, Aeschylus' attempt to understand the effects of the Athenian victory from the victims' point of view is all the more remarkable given that he himself, like most of his audience, had fought on the winning side.

The idea of re-setting The Persians in the Iraq of Saddam Hussein came to Sellars while he was working on the 1991 premiere of Klinghoffer - a Passion-style treatment of the fatal 1985 Achille Lauro hijacking. Rehearsals coincided with the outbreak of the Gulf war, and Sellars recalls the pain of watching the news on CNN 'and then walking into the rehearsal room to see very similar events taking place'. Even more painful was the knowledge of what wasn't being shown - thanks to the censors. 'I have come to think of theatre now as almost an alternative information system - what can't be shown on television can be said on stage. In America the war in Iraq was shown with no Iraqis at all - dead or alive. So, in this evening, we're saying come and meet a few]'

Not that Robert Auletta's adaptation ('I do think that the notion of translating the Greeks is slightly presumptuous,' Sellars quips) seeks to drive home the historic parallels. While the Persian War saw the defeat of a mighty world power by an upstart and vastly outnumbered set of Greek city-states, the Gulf war witnessed the reverse - 'the triumph of the old world giants over a midget'. And, of course, there's irony in the fact that Iraqis are here substituted for the Persians whose descendants are the very Iranians who are today Iraq's deadliest foes. 'But once we get over these strange crossed wires, we try to ask a whole series of moral questions' - above all, about the true meaning of military victory. 'We're all suffering this century from the effects of borderlines drawn by bloody victors in earlier wars. So what, really, is a victory? What is the victory of the Gulf war, for example?'

It was for the collective discussion of just such large issues, Sellars believes, that the Greeks invented theatre - 'as a preparation for jury duty, really, so they could judge what was just or unjust in complicated cases. 20,000 citizens would be sitting together watching discussions of rape, incest, murder and how you treated the prisoners in the last war - everything you wouldn't dream of talking about in polite conversation.'

It was to tackle just such big issues that Sellars moved into opera seven years ago, after seeing the 'straight' theatre reduced to nothing but 'shows'. 'Opera gave me a place where I could put large-scale issues in the biggest theatre in town - a good place to hold civic discussions.' Now, with The Persians, he trusts the world is ready for some 'serious' theatre again. But he's a little depressed at finding nothing here but posters for comedy. 'I mean, do people do serious productions at Edinburgh?'

(Photograph omitted)