DANIEL DAY-LEWIS— who raced in moccasins through the New World's forests in The Last of the Mohicans, and danced through swinging sixties London in platform shoes in In the Name of the Father—is limping awkwardly as he enters a midtown Manhattan hotel suite. Tilted haphazardly to the left as he tentatively moves forward, the sturdy actor plops down on a straight-back chair, breathes a sigh, and grins.

Day-Lewis's current plight, a herniated disc in his lower back, is the result of giving yet another movie his all. He spent two years training with Ireland's former featherweight boxing champ to become convincing for his role in The Boxer as IRA pugilist Danny Boy Flynn. And that was before he reteamed with Jim Sheridan—his director on My Left Foot and In the Name of the Father—for the grueling, seventeen-week Boxer shoot. Finally, once he was no longer actively training, the back gave out.

Day-Lewis, now forty years old, is legendary for his intense approach to his work. He spent five months carrying a primitive flint rifle to prepare for The Last of the Mohicans , and for his role as The Crucible's John Proctor, he spent weeks planting fields with primitive seventeenth-century tools. For his Best Actor Oscar-winning work as paralyzed Christy Brown in My Left Foot, his committment was so complete that he refused to walk on the set. As his Boxer co-star Emily Watson says, "I never met [the real] Daniel."

The real Day-Lewis can be equally difficult to locate during an interview. He steadfastly refuses to discuss his private life (once a target of tabloid scrutiny, he's now married to actress-director Rebecca Miller), and he initially seems a bit uncomfortable when asked about his unusual acting method. But it doesn't take long for the London-born thesp to open up and shed some light on the politics and history behind his films, his remarkable career, and the reasons he doesn't act like any other actor working today.

How did you hurt your back?

I had an injury while I was training. The time was very tight and I jumped in at lunch hour for a training session or whenever I could. On this one occasion I jumped in cold and just didn't warm up enough and I knew I'd done something but we managed to get through [the shoot] okay, although I was 'seized up' for a few days. I think it was something just waiting to go. [The current injury] just happened a few weeks ago [in early December].

In boxing, when you're fighting, there's a lot of stress on the lower back. If you're twisting and turning, if you over-reach on one occasion, all your weight goes over the lower back and it can quite easily go out.

Has surgery been recommended?

Possibly, but only a very small surgery. More than anything it's like a useless leg, but the pain is minimal. It was pretty bad for a while but the treatment's relieved it somewhat. It's just like a dead leg. Don't go into too many details. [Laughs.] I might not get insured for any [other films]!

Sheridan told me when he started The Boxer he didn't know what the ending was going to be.

We didn't have a clue. Or the beginning or the middle, come to think of it. We only knew the end about two weeks ago. Sheridan often begins filming without knowing how his films will end.

The Boxer is surprisingly critical of the IRA. Is this an anti-IRA movie?

It doesn't set out to be an anti-IRA film, although the effect may be to give people an understanding of a world which they feel very off-putting. Think of it more as a pro-peace movement film. The Irish Republican Army has gone through so many transformations over the years. There's still this great romantic ideal from 1916 that people hold onto, and it doesn't hold up under contemporary scrutiny. What we're looking at now is an organization that has got to transform itself if it's going to do any good at all. So maybe there could be an IRA, if they would only accept that acts of terrorism were not the way to go.

Britain's new Prime Minister, Tony Blair, recently hosted IRA leader Gerry Adams at a meeting at his residence on Downing Street, a development that would've been considered impossible a decade ago. How does that make you feel?

It's hard to remain optimistic about the situation in Northern Ireland, but I think one has an obligation to remain optimistic, even if it's a dulled optimism. But the fact is at the moment things are moving. That is largely due to the great efforts being made by the new British government - and I'm all in favor of that. And I haven't been in favor of British governments before Blair. Because how the hell when two armies, in effect, are entrenched and staring at each other over a parapet with hate and fear and bewilderment, how can you change that unless you enter with some open dialogue?

You're English, yet you have this image as an Irish patriot. Is this an accident of fate, or something you've cultivated?

I think it's a mixture of two things: part accident and part will. I am English and I've had an English education. I'm very proud of whichever part of me is Irish, but I am English. I grew up in England. My mother's family is from Latvia, for God's sake. It's not like I can claim to be an Irish thoroughbred, and I don't. I'm very proud to get an Irish passport because my father was Irish and I keep that and travel with it. Maybe there's a tradition there too, of people who are Anglo-Irish who have become acutely aware of the role the British have played and wish to do something to redress the balance. I live in the Republic and there's no battle to be fought there. But when I first came to Irish history—because it's not taught in the British educational system—I was so astonished at the part the British had played in the history of Ireland, and so ashamed in a certain sense. It made me feel a kind of kinship with the place. Not because I was Irish, but as a person reaching out across the sea in a way.

Talk about the pressure of coming to do a third film with Sheridan after the success of the first two.

The only way to survive is to have tunnel vision. There's even more pressure on Jim than on me, because of the money [$25 million] and the weight of the production. It's not the preconceived expectations, but the greatest stress was we started from the ground upwards, and the way we work relies on chaos. We hope order and some kind of sense will come out of it. The fact is, we were reworking and reworking the script until we finished shooting it. And then we went and shot some more. We had to find its borders and its boundaries. There was a good deal of stress involved in that. The important thing is to not have any hopes for the film. That's hard to do but I try to just do the work and see what happens. That applies to the other two films we did as well. I had no expectations off the other films, what came afterwards was just icing on the cake.

Your relationship with Sheridan is obviously close. Do you see it as father and son, or more a couple of brothers?

Quite a brotherly relationship, more rough-and-tumble than what would be between father and son. It's a more open relationship than what people would generally see as a father and son. Surrogate father, no. But certainly brothers in arms.

Your string of acclaimed collaborations with Sheridan has brought comparison with Martin Scorsese and Robert De Niro. How do you feel about that?

I think it's a mad comparison to make. If you look at the trajectory of work of those two—Raging Bull, New York, New York, Taxi Driver, GoodFellas, Casino, Cape Fear, King of Comedy—those guys, gosh, they have two handfuls of extraordinary films. Shay [his nickname for Sheridan] and I have just completed the third. Those two men are in a league of their own. It's crazy to make comparisons.

I just spoke with Robert Forster, who's been acting for thirty years now and is in Quentin Tarantino's Jackie Brown. For Forster, who you are is what is going to inform your characters. He says an actor only has himself to give. I thought then specifically of how you differ in your approach, where you transform yourself to become this other person. You've been doing this now for over a dozen years, starring in films that reach an international audience. Can you still really lose yourself in a role?

The fact is, it's weird. [Grimaces.] Although it's not like I consciously set out with a pre-formed idea that I'm going to become somebody else. It's more to do with an exchange of some kind that takes place, because I'm drawn towards a life for a period of time, which I find intriguing for one reason or another. It's not with the intention of undergoing a transformation. If any transformation takes place, it happens as a by-product of the work that goes on in an attempt to meet this person on their own ground. It's not that you just become someone else. That doesn't happen. Whatever finally takes place, it's bound to contain within it a large part of one's own internal mechanism, I suppose, as much as it does another. But I find it helpful to me at any rate to create the illusion—or delusion, whichever way you look at it—of occupying someone else's shoes in my work. That's where I find pleasure. But the idea of a total transformation is a little bit mythical. I don't necessarily believe in that. I love it when people feel that another life has been told them and it's not recognizably one's own. That's what my work is; I think that's where it lies. If I were just in the business of continually re-exploring my own sensibilities all the time, then I think I would lose interest that much quicker. But we're still one and the same person—it's the same engine, it's my desire that always draws me into that place. So it has to be my desire that propels me into discovering what goes on in that place. So finally, you could just say it's all you. [Laughs.] I've probably tried to say it before, and I don't know why I'm trying again, but I've never achieved any explanation that made any sense. [Laughs.]

I wonder if you ever say to yourself, "This is a new way of approaching a role. I'm not going to do like I did for that other film."

Again, the same rules never apply. There's no system or procedure whereby I go from A to B, where I've left one place for another.

For The Boxer you were in training for years before you really decided to do this movie weren't you?

I was in training for about two years, yeah.

That was long before there was an actual start date for the movie. Yet when you were doing interviews to promote The Crucible, you wouldn't confirm that you were going to actually make The Boxer.

I was in training for two years and for a large part of that time, I genuinely kidded myself that the film was fairly unlikely. Because wherever the truth might lie, I like to think I'm doing things for their own reasons. Somehow, if I place a film at the end of this tunnel, it's going to already make conscious the sense of illusion about it. So I begin at the outset saying, "This is me. I'm interested in this." Of course the fighting, the boxing and the training, all that stuff that goes on, that's just between me and whoever I'm doing it with. That had nothing to do, in the early stages, with Danny Boy Flynn. Later on, it became his fight and his game and his life. But in the initial stages it was just me being interested in that.

Any idea what you're going to do next?

No.

Where is home for you? Is it England and Dublin and New York?

England, [just] for visits, because my family and a lot of my friends are still there. Home is more between Ireland and here.

You're forty. Do you have a feeling that you've hit your prime, that you know yourself better now?

It'd be strange to say yes, bearing in mind the intense battleground that was the filming of The Boxer. But in an overall sense, it's true. I have a far less troubled attitude toward the whole business. I know what I like and what I don't like about it and there's no sense worrying about it anymore. I'm clear about what I need to do and what I want to do and there's no sense losing any sleep over it.

Will you ever return to the stage?

Hard to say. I can't imagine it happening. Then again, it could.

You don't miss it at all?

No, I don't miss it at all. I thought I would, but then it never occurred to me that I wasn't going to do it again. Although a lot of people thought just because of the Hamlet episode [in 1989, Day-Lewis hallucinated about his late father during a performance, and walked off the stage] that this is some terrible dark secret in the closet. But it never seemed that way to me. I thought I'd just take a break for a while. Things just worked out differently. In my mind I thought I'd do some work in the theater again, but I'm not very well suited in temperament for the stage. I'm not really well suited to film work either. [Laughs.] Maybe you could suggest an alternative to both of those.