It's not often that the leading actress of her generation humorously likens one to Jesus, but Fiona Shaw – a tidal wave of unsystematically creative thought – overflows with manifold surprises at each of the various meetings we had in preparation for this article. The setting for the wry Christ comparison (which tells you much more about her than it does about me) was the National Gallery. I had thought it might be fun to try to get to know this woman, who has increasingly positioned herself in the public eye (on television and radio) as a cultural commentator, by talking to her about works of art other than herself. And so it proved, but I had not reckoned on the fact that these encounters would coincide with an explosion of acting genius by Shaw on London's Olivier stage.
I described her performance as Brecht's Mother Courage as "phenomenal" when I reviewed it for this paper. But that early judgement was restrained by comparison with that of her performance towards the end of the run. Tipped off about this, I saw the show on two further occasions – an exercise conducted not just out of journalistic diligence, I must confess. And thus I found myself meeting Shaw for a final session in her dressing room after the last Sunday matinee of Deborah Warner's inspired, counter-intuitive National Theatre production.
Between handing out drinks to friends such as Edna O'Brien and Suzanne Bertish in her cramped backstage quarters, and heading off afterwards to the Rolex Awards across the river, she spent two hours expending energies that most actors of 50 would be jealously conserving for the footlights. She engaged in free-floating discourse about everything from the intricately argued keynote Lyttelton Lecture on Shakespeare and the Irish that she is soon to give in Dublin, through the origins and manner of her famous creative collaboration with director Deborah Warner, to which roles had made her feel embarrassed in front of her parents. Her father is a former eye surgeon of Cork and her mother is a singer, wit, and not-so-secret source of some of Shaw's characterisations. Prodigious as this performer has always been, she is – for various reasons; some to do with ageing, none to do with mellowing – only now getting into her true stride as an astonisher.
The actress is about to have, if not a white, then certainly a tight Christmas; and a somewhat schizoid one, at that. She will be rehearsing The Waste Land, a re-angled revival of one of the great Shaw/Warner shows. Presenting a piece in which she is unnervingly possessed (as a medium is) by the trans-historical identities in TS Eliot's modernist masterpiece (a spiritual quest; a neurasthenic echo-chamber of overlapping voices; a London-based labyrinth) the production opens for twice-nightly business on New Year's Eve in the atmospherically perfect Wilton's Music Hall, the East End venue which just so happens to be celebrating its 150th birthday. It would be hard to better this show as a commemorative event. Not only is Leman St, a thoroughfare referenced in the poem, within spitting distance, but it was the Shaw/Warner Waste Land collaboration that reawakened Wilton's from its long latter-day desuetude on a cold December afternoon 12 years ago. The whirligig of time can, it seems, bring in more than its revenges.
"We've done the piece all over the world in different site-specific locations," she said. "In Dublin it was staged at an abandoned English fort on top of a hill in Phoenix Park, in one of the low-dome-ceilinged 18-century bunkers where the colonists kept their gunpowder. The space was very abstract – it was almost like walking into someone else's brain, which is appropriate for the poem. Epidaurus, where we were the first people to put on a modern [play] when we took Happy Days, also reminded me of an exposed brain carved in limestone on the hillside..."
With The Waste Land, there have also been some fascinating near-misses on the location front. "In Brussels, Deborah found an abandoned department store, which had a marvellous lift-well down the middle. She had plans to put me at the bottom of the well, with the audience looking down. It would have been a terrific spatial relationship. But permission fell through, as it did for putting me in one of those booths in the mission-control[-like] new conference chamber of the European Parliament. The audience would have sat in green armchairs receiving the piece through translations headphones. But the parliament didn't care much for the title. Well, it's not exactly upbeat and, when Deborah appealed to Neil Kinnock's office, they said, 'now if it had been a Welsh poem, there would have been no problem'. At one stage, there was a joke going round that Deborah wouldn't be satisfied until she'd launched the show into outer space."
Instead, they have come back home to the site of the London premiere. In between have come the terrorist attacks of September 11, 2001. How this will affect their interpretation of a poem that struggles to find some basis for spiritual renewal will, it seems, only emerge when the pair starts rehearsal. I suspect that it will colour the notion of cataclysm as transmitted by Shaw's awesome channelling of the poem's voices.
At the same time, Shaw has been preparing for a rather different role as Lady Gay Spanker, the horsey, older, love-interest and high-comedy turn in Nicholas Hytner's forthcoming National Theatre revival of London Assurance, by the 19th-century Irish writer, Dion Boucicault. She will co-star with Simon Russell Beale, an actor who has, in a more contained way, her kind of bravura braininess. I bumped into him while the piece was in preparation, and he told me a lovely anecdote about professional life with Shaw on the set of Roger Michell's excellent TV-film version of Persuasion: "About eight actors were sitting round the dining table waiting for the lighting and the sound and all that to be set up. To while away the time, we were talking inevitably about sex, theatrical and film gossip – the usual stuff. I think it was Amanda Root who suddenly said that we should try talking about something more interesting and profound. And I replied: 'Funnily enough, this morning I was reading a proof of the existence of God by St Anselm.' Quick as a flash, Fiona said: 'Ah yes, I know it. It's good – but I can disprove it.'" Sparks seem destined to be struck between them.
Her combative comic rhythms provide one of the reasons why Hytner, who has known Shaw since the early 1980s, when they were both youthful members of the RSC, recalls her as "a voluble imagination". He is reviving the play that made Boucicault's reputation in his early precocious years of London exile. Shaw made a similar migrant's journey when she landed on these shores, fresh from a philosophy degree at Cork, to embark on a medal-winning course at Rada. Her theatrical background had, it seems, been minimal. I asked if she, like the similarly dazzling Mark Rylance, had had the liberating early experience of watching her parents play theatrical roles. "I once saw my mother playing Mary Magdalene in a parish event. But she had to put the role aside in order to go and front the choir who were singing at the same occasion. She left the stage half-way through the Crucifixion". That must have been the closest you could get to an (inadvertent) Brechtian alienation effect in the heartland of middle-class Catholic Ireland.
Shaw used to ride to hounds as a young girl in Ireland and, to get her Lady Spanker juices flowing, she was due to go out with the hunt. So that's her Yuletide for you: Eliot's "fragments" one minute; fetlocks the next.
Early on in our talks, Shaw declared, "psychotherapy has destroyed eccentricity both in life and onstage". She talked with affection of the great, intrepid individualists amongst her professional forebears; including Dame Sibyl Thorndike, who can never knowingly have consulted a self-help book in the course of a doughty and unfeasibly philanthropic life.
With a father who was a social hub, Shaw had from childhood the chance for close, non-judgemental observation of a full range of social "cases". All her early roles for the National and the RSC were in comic parts, in plays by Sheridan, Shirley and Shakespeare, which harnessed her flamboyant gift, making mannered high artifice sound utterly natural.
Her first tragic part was as a wasted Electra, warped by grief and frustrated revenge to the thinness of an axe-blade, in her first high-profile work for Warner in the now legendary 1988 RSC revival of Sophocles's play. The production came up in conversation during our trip to the National Gallery to view The Sacred Made Real, an exhibition of 17th-century Spanish sculpture and painting that makes the bloody suffering at the heart of Catholic doctrine and worship disconcertingly life-size and graphic.
I too am a lapsed, lingeringly hung-over Catholic, so we traded many an anecdote of scandalised survival. It was here, with characteristically quick wit, that she likened me to Christ. I had just told her of a life-changing experience with the nuns when I was seven. A puce-faced bruiser in a wimple asked the class why we should pray for the souls in Purgatory. My arm shot up: "Please, Sister, because one day we will be there ourselves". Sister Mary Ethna bore down on me. "You selfish little boy – we pray for the souls in Purgatory because they cannot pray for themselves". I babbled back. "But Sister, Jesus says we should love our neighbour as ourselves".
This greatly tickled Shaw, who kept bringing it up from then on, and cackled: "But that's the boy Jesus disputing with the Elders in the Temple – and you were much younger too." Her response is an example of her generous teasing, and of the lightning speed with which she makes connections. It also bears out one of her reasons for reading philosophy at university. "Catholicism awakens philosophical questions in bright children by trying to strangle those questions before birth".
Electra cropped up, though, because of the physical and psychological pain obvious in the Counter Reformation statues around which we perambulated. "I've often used physical pain as an actor. Before I went on as Electra, I used to do leg stretches that would make my eyes water. The point about some of these great tragic figures is that they are at a pitch where they are no longer self-aware. You have to match them in this. Physical pain can be a way of attaining a state where the brain is bypassed and the language just flows through you."
The brain made several guest appearances in our confabulations. Shaw recently had hers scanned by neurologists at London University in an effort to identify whether actors access different parts of their grey matter from other people when recalling lines. (They do; they access an area otherwise noted for spatial manipulation, such as the tilting of the figure eight so that it looks like a pair of glasses, which suggests that a kind of architectural context is crucial for actors when remembering lines). The most difficult part for Shaw, she revealed, had been when she was told to empty her mind. "How can you not think? I was trying to not think and up popped the memory of my dog dying."
Shaw has led, in some respects, a charmed life, but the strong shadow of bereavement has fallen across it at times. One of her three brothers was killed in a road accident before she went to Rada. "My mother still introduces us as her 'surviving children'," she noted wryly. "We just think of ourselves as her children..." Her departed sibling came up when, in her dressing room after her knockout Sunday matinee turn as Mother Courage, I asked her about whether there were any roles she had been embarrassed to perform in front of her parents. "I wasn't wild about them seeing my Richard II [her celebrated, if controversial, portrayal of a very manipulatively child-like deposed king at the National for Warner]. I just thought that they already have three sons, they don't need another. And when Richard was brought on at the end in his coffin, Deborah saw my father jump out of his seat."
And what about Electra, whose "issues" with her dead father are her entire raison d'être? "It's funny, but while we were doing that piece, I was having a short session of psychotherapy and, one day, the therapist said: 'There's a play I think you should read called Electra.'" Shaw's mind, though, during those performances, was on her brother rather than her father. The return of Orestes and the heroine's recognition of him elicited a response of pitiable but also deeply ugly hysteria in this actress's revelatory portrayal; there was an autobiographical component in her take on the part.
In her dressing room after her other guests have gone ("Did you notice they were all Catholics? There wasn't a single Protestant. I seem to be meeting Catholics everywhere I turn at present...") she pondered on the kind of performer she is. "I would confess to you that I think I have always acted with just a tiny line between who I am and what the role is." Shaw, in her brilliantly unsystematic Irish way, is a Renaissance woman, up for anything – from documentaries on animals and speech that send her off to the Galapagos Islands to having her brain discussed on the Today programme. Collectively, this generation of greats demonstrates that it's not just through the honing of technique that you can better yourself as performer, it is through having a deep offstage life too.
There is a school of thought that argues that Fiona Shaw has spent too long away from comedy, and that her creative partnership with Deborah Warner – which began, Warner recently told me, in 1988, when Shaw managed to respond to 90 detailed rehearsal notes on her performance as Electra with the dexterity of a Wimbledon champion hitting back every variety of shot in the book (Warner mimed the process) – has been a gigantic aberration. One would want to counter by saying: but look at the brilliant streak of comedy in the Shaw/Warner collaborations – a Hedda Gabler who withered her provincial world with over-the-top wisecracks that were the product of boredom and shame; and a child-murdering Medea exiled into a vertiginously destructive irony that devoured more than her progeny.
There are also poisonously resentful people who dislike the partnership because – in what is to them ascending order of horror – these are not just two women, but two gay women, and, sad to say, two gay women who have ideas. To this prejudiced group, it is perhaps idle to object that the pair's relationship is not a sentimental (nor a sexual) one, and that, far from being an égoïsme à deux, it thrives on fundamental differences between the centripetal, Quaker qualities of Warner and the centrifugal, firework, intrepidity of the lapsed Catholic Shaw.
Exploding these prejudices in the most emphatic style is the fact that it is Warner who has just directed Shaw in what I believe to be a watershed performance in the title role of Mother Courage, in a staging that is to have a post-National Theatre life touring Europe (and, possibly, beyond). The production will go down in history as the one where, as a massively exuberant alienation-effect in a piece about the moral ravages of war, the play kept turning into a stadium rock gig. Shaw's Courage mutates periodically into a parodic rock-chick-diva whipping up the onstage band of Duke Special, who has wandered into war-torn scenes as a benignly estranging, ineffably pacific presence. All of that is true. But it is also the show, I think, in which Fiona Shaw finally "came out" as the kind of actress and the person she is. She now has what she did not have in youth: a magnetic warmth that can carry an audience to hell or heaven and back.
Shaw's Electra, Hedda and Medea came at time in the course of feminism when it was possible to analyse the ways in which, far from being pure victims, these women collaborated in their own downfalls – hence the principled rebarbativeness, the studied repression of easy charm. And it's possible that, when Shaw says that her parents already had three boys, she is also implying that she was not prepared to give them the conventional girl who would have been the counterbalance. There was a properly embattled quality about the younger and early-middle-period Shaw. It's not that it has vanished now; rather that you feel an acceptance in her of who she is at the very moment that it is expanding.
So, where the conflicting qualities of Mother Courage – bravery, cowardice; anti-war, war profiteering; concerned mother, wildly irresponsible parent; etc – normally cancel each other out, in Shaw's portrayal they give the woman the depth of a character from Shakespeare. You can see elements of Falstaff; you can see the showbiz mother-from-hell in Gypsy; and, since the first night, Shaw has added the authentically ghastly touch that, whenever Mother Courage is on the spot emotionally, the muscle memory of her old bravura haggling days takes over her arms and hands in a compulsive, desiccated mime. It's wonderful and excruciating. And last, but not least, you can see Fiona Shaw herself, actor and role finding each other in an endlessly ricocheting reciprocity.
So the future, which begins with The Waste Land and London Assurance, is looking pretty limitless. Saying farewell,, Shaw suddenly added: "I feel I may have been a bit too cautious..."
'The Waste Land' is at Wilton's Music Hall (tickets 020-7452 3000; nationaltheatre. org.uk) from 30 December to 10 January; 'London Assurance' opens at the National Theatre on 2 March (tickets as above)