This tall, slightly shambling, incredibly softly spoken man is only interested in theatre, which is why almost nobody outside the business knows him. Worse still, even insiders can't rise in his defence by citing his possibly groundbreaking reinterpretations of classics. You have to trawl a long way back through his CV to find anything approaching an old play. For the last six years he's worked almost exclusively on premieres from living writers. As he puts it: "Without new writing, you end up with cultures where theatre becomes like opera, endlessly repeating old repertoire." Trouble is, this is the surest route to oblivion as everyone focuses on the writing rather than the production.
The tide, however, is turning. Macdonald's meticulous direction was lost beneath the scandal surrounding the content of Sarah Kane's Blasted, but you couldn't fail to notice his mesmerising, clinically precise production of her play, Cleansed. Not to mention Roberto Zucco for the RSC. His startlingly atmospheric production literally left after-images burnt on to the stage from a highly charged cast who, under Macdonald's astute, astringent direction, grabbed immense possibilities with both hands.
Neither of those are among the century's great laugh-fests. Which is one of the reasons why Macdonald is changing tack with his latest production, The Triumph of Love. "I didn't want to paint myself into a corner,"he says, smiling. Yet there's much more to it than a switch of mood. For years he's worked closely with writers, from Sam Shepard and Nick Grosso to Caryl Churchill, but this time he's going it alone. Marivaux won't be in rehearsals because he died in 1763. Since which time, aside from the odd, insipidly "tasteful" French production, no one paid him serious attention. Andre Gide went so far as to describe a play as being "as boring as Marivaux".
Macdonald, though, compares his see-sawing reputation to that of Vermeer, another master of psychological realism. "He languished in neglect until the plays were rediscovered in France in the 1950s. Now he's done more often than Moliere." Even here, Marivaux is the man of mode. Director Mike Alfreds began it all in 1983 with Successful Strategies followed by the hilarious The Game of Love and Chance co-directed by Macdonald's former Oxford contemporary, Neil Bartlett. Another revival of the latter play was one of the hits at this year's Lift, while Bartlett received rave reviews for his revival of The Dispute. He even surfaces as a character in David Greig's The Speculator, about to open at the Edinburgh Festival.
The reason, Macdonald thinks, is simple. "There are around 30 plays, all of which are good. They're in prose and, in lots of ways, 18th-century concerns are much closer to our own - the dawn of bourgeois individualism, if you like, the drama of private lives and loves." He also loves Marivaux's compassion (a quality that links him to the admittedly more confrontational Sarah Kane). "He's an out and out humanist. That generosity is very hard for contemporary writers, but it's something we could usefully have in a theatre in 1999."
There is one further appealing quality. Marivaux wrote for a company he knew intimately, the king's company of Italian commedia dell'arte actors who had been in Paris on and off for 150 years. "But the bottom fell out of the foreign theatre market. They loved the clowning but were bored with seeing it in a foreign language. That's when they realised they had to hire writers." One of them was Marivaux, a lawyer and journalist who wrote 19 plays for them and another 11 for the Comedie Francaise.
His Italian company consisted of incredibly skilled physical comedians used to playing one stock character throughout their working lives - the soubrette, the young lover - but Marivaux played to, and furthered, their strengths. "Within each play he would push an actor to do something that developed what they had done before, or set them a new challenge. Those who didn't speak French very well had small parts but lots of action. It's unimaginable for us because, by and large, we can't afford ensembles but also because writers never have long-term relationships with a company."
Macdonald passionately believes theatre is about acting, which sounds like a truism until you realise that it's low on the agenda in much current work. "These plays are, to an extraordinary degree, about acting and truth. The Triumph of Love is quite relentlessly about somebody acting, or rather, lying. And that I find fascinating. It allows me to focus on what full-on theatrical acting is in a very rich context."
He's certainly attracted a distinguished cast of theatre specialists, distinct from practitioners of the increasingly behavioural style demanded by TV. Helen McCrory plays the princess, secretly and disastrously in love with the rightful heir to her kingdom who has been brought up to hate her. "It's one of the most extraordinary parts ever written for an actress because she has to play 12 love scenes, one after another, as both girl and boy, against the clock until she drops." Mercifully, she's surrounded by talent as varied as Linda Bassett and Tony Haygarth, and Theatre de Complicite actor Antonio Gil-Martinez.
This diversity is also a reflection of Macdonald's roots. Surprisingly for someone seen as so script-based, he studied in Paris for two years with Jacques Lecoq and Philippe Gaulier because he wanted to discover something about theatre which wasn't about text. "I was worried I might have to work with a lot of serious people in white face wearing leotards but, luckily, I met Simon McBurney wandering around in a baggy jumper with holes in and peroxide hair and I thought, `oh right, you can be scruffy, not puritanical'."
Yet despite his continuing brimming pleasure in working with actors, he's itchy about the state of theatre. He senses an impending crisis. "In a five-week rehearsal period, there's a honeymoon of a week and then a sprint for the line, so any possibility of a methodical process of work is lost. I'm passionate about that. I don't think we do theatre very well at the moment." The strain, he argues, is showing. "The sense of why theatre's doing what it's doing has got lost. We have to stand back and take more time to know why we are doing it within this culture of the great hype."
He knows his solution is out of step with the economic spirit of the times, but he believes that for theatre to progress it must return to ensemble. "For me, theatre is primarily a transaction in confidence between a group of actors and the actors and the audience. What people go to the theatre to buy is confidence, and the only way you can utterly achieve that is to work together over a period of time, the one thing which isn't available to us in any reliable form. I surprise myself by saying that, because it wasn't something I looked for until quite recently. But as soon as you go back across the centuries, it's clear that most of the great plays were written for ensembles. They're about writers and their relationship to a group of actors. Whatever else we've found, we've lost sight of that."
That said, he's very happy with the enthusiasm and the physical circumstances of this production which previews and tours before the spotlight of a London run. Even so, he permits himself a wistful smile. "At the risk of sounding crass, I'd like to work out how to do theatre properly. I'm fed up of flinging it together."
At The Almeida from 29 July, then Norwich, Bath and Malvern, 0171- 359 4404 for detailsReuse content