Thoughtfully, he also establishes as part of performance a running joke - a German tourist impression (originated, he says, by Skipp Sudduth, who was in the Iceman cast), which he launches into without warning every ten minutes or so. Then, at his suggestion, I accompany him to his regular boxing lesson at the Hollywood Gym on La Brea, where a smiling ex-lightweight named Terry Claybon subjects him to an amazingly grueling workout. It's considerate of Spacey, really, to provide me this ready-made color setting, and it's not entirely useless to me: As Spacey's instructor puts him through his arduous paces, I get a vivid senseof his powers of concentration, along with his doggedness, his stamina and his willingness to learn something new - all qualities that help account for his success as an actor. According to Claybon, he's doing "unbelievably well" in only third week of lessons, but after a while I begin to feel awkward just sitting outside the ring staring at this 41-year-old man sweating and breathing hard. This is not what I need to know about Kevin Spacey.

The best way to "get" Spacey, I think, is to listen him talk about acting and the world of theater. His knowledge of his profession is encyclopedic, and his attitude toward its practitioners, particularly the leaders of the tribe, is positively reverent. (Not a word you'd associate with him in any other context.) And his fellow actors and other show folk are starting to sound almost reverent about him. Curtis Hanson says, "He's a dream to direct." Judy Davis - one of the greatest actresses alive and a person who, one senses, is not easily impressed - describes him as "terribly funny, very smart, very generous". Helen Hunt, who plays opposite Spacey in the new Pay It Forward, quietly gushes, "I've felt a rapport with a lot of actors I've worked with, but rarely have I worked so deeply and so sort of intricately with another actor." And she makes a prediction - "I think he's fated to do big, huge things creatively" - that echoes something that Jack Lemmon says to me: "I know that the future is rosy for him." After talking to Spacey's colleagues, I feel as if I've sat through one of those AFI Life Achievement Awards dinners.

But I'm not surprised, because in listening to Spacey describe his creative process, expound on the history of his profession and reminisce about past productions, I begin to suspect he's a different person - more alive, more fully engaged - when he's working than when he's not, and also that theatrical people are more real to him than the rest of us, who aren't in on the joke. He has studied his acting heroes so thoroughly that he can speak of the dead as if he had known them: His analyses of Henry Fonda, Jimmy Stewart, Humphrey Bogart, Montgomery Clift and his "all-time-favorite", Spencer Tracy, are like eulogies. He even thinks of his boxing lessons (which he's taking solely for exercise, not as preparation for a role) in terms of acting: "Terry keeps telling me, 'If your foot's too far off the ground, I know you're coming at me. You have to not telegraph what you're going to do.' It's the same thing with acting. You don't want to telegraph what's coming. You want it to make sense when it happens, so an audience says, 'Of course.' You may even have done twelve takes, seven angles, but it all has to look like it just happened, at exactly that moment. That's really the trick - the trick is not getting caught at acting. And Tracy didn't get caught at it better than anybody."

Not getting caught at it is clearly Kevin Spacey's highest goal, but it's one that, for all his skill, is tougher to achieve in what we nonperformers consider the real world. When he tries to show me he's a regular guy, I can catch him acting, because actors are not regular guys: They just play them in the movies. Effects that work superbly on the stage or the screen lose a little something in the less orderly realm of ordinary life. Spacey knows, for example, the power of anticipation in theater and film - the interest an audience builds up while they're waiting for the appearance of a character that the other characters have been talking about. Iceman is a prime example. For a good hour, we hear, from everyone in Harry Hope's bat, "Where's Hickey? Where's Hickey? He should have been here by now" - and when he finally makes his entrance, it's like the Second Coming of the Messiah.

And that's not the only role in which Spacey has played the man everyone has been waiting for: He has done it in Seven, in The Negotiator (1998), to some extent in The Big Kahuna, and - in a peculiar way - in The Usual Suspects. (He'd play Godot if it were humanly possible.) But when he makes me wait, for an hour and a half past the time we agreed to speak, I somehow fail to experience the thrill of anticipation I might feel at a performance of Iceman.

But it's a beautiful, relatively smog-free L.A. day, and we're sitting in the courtyard of the Sunset Marquis in the West Hollywood with the sun reflecting softly off the pool, and the tension quickly disappears, because all we talk about is acting, which is what Spacey knows best and seems to care most deeply about. And if he's being anything less than honest, I'm not catching him at it.

He doesn't say a lot about his preprofessional life. He was born Kevin Spacey Fowler, grew up in an oridnary Valley suburb, got involved in his high school drama club and then headed for New York to study acting at Juilliard. Although he left school at the end of his second year, he appreciates the value of the "mostly technical training - learning about speech, voice, accents, posture, even fencing" that he received there. "I know that if I hadn't had all that, I wouldn't have been able to get through Iceman." (The school recently awarded him an honorary degree.) Within a couple of years, he was appearing on Broadway in Ibsen's Ghosts, with Liv Ullman: He claims to have been "the worst Oswald in history," although he's had a hard time convincing Peter O'Toole that it was worse than his.

After leading the life of a young New York actor for a couple of years, somehow avoiding doing soap operas and commercials (he blew his one commercial audition by arguing with the casting director about the meaning of the word nebulous), he was cast in a high-profile Broadway revival of O'Neill's Long Day's Journey Into Night, where he found a mentor, Jack Lemmon. Lemmon, who says he thinks of Spacey "like another son", tells me that Spacey got the part by stealing - from a little old lady, no less - an invitation to a reception for the play's director, Jonathan Miller: "And he confronted Jonathan and said, 'You've got to read me, because I know I'm right for this.'" Lemmon adds, "There's a difference between raw nerve and chutzpah on a healthy level. Kevin has plenty of ego, but it's balanced, and he points it in the right directions. He goes after things that are terrific for him. He has very, very good judgement."

Spacey, in fact, prides himself in knowing what's right for him, and has no patience with actors who think they should be up for every part. "You can only think that if ego and ambition are more prominent in your psyche than anything else, and those are not two good things for an actor to operate on all the time." What strikes me as I listen to him tell stories about the various plays and movies he has worked on is how detailed his memories of his creative process are: He defines the problems each role presented with remarkable clarity and specificity, is surprisingly candid about instances in which he felt he needed help and manages to turn every one of his theatrical anecdotes into a shapely little lesson on craft. He speaks, for instance, about using his TV stint in Wiseguy "as a way to learn about myself on film," because the small roles he had been getting in movies weren't teaching him enough. He illustrates the importance of having historical references by pointing out the hairpiece he wore in L.A. Confidential: "I wanted Montgomery Clift's head. We called my piece 'Monty' whenever I put it on." And he gets really animated when he explains to me how, during rehearsal for Iceman, he discovered that he couldn't do Hickey's famous fourth-act monologue the same way every night. "I told the director [Howard Davies], 'It's going to be self-loathing, it's going to be funny, it's going to be sad, it's going to be lonely, it's going to be terrifying, it's going to be a lot of things a lot of times, but I don't know when and I don't know why. I just want to show up every night and be honest; that's all I can hope for.' And approaching it that way kept the play incredibly alive for all of us." That's my condensed version of what, in Spacey's telling, is an extremely long and meticulous narrative of the rehearsal process, a kind of epic account of the planning it takes for an actor to arrive at something spontaneous and instinctual, and of the infinite resources of artifice he needs in order to be honest. He has an almost blissful look on his face as he tells it.

That's what actors on Spacey's level live for. I ask everyone I talk to about him why they think it is that this man - who is not young and not remarkably handsome, and who has been for most of his career a versatile character actor rather than a romantic leading man - has become a star, and even a sex symbol. No one can give me a satisfactory answer. They all cite his sense of humor (which Judy Davis perceptively characterizes as a "knowing, modern kind of humor") as one component, and then they get stuck, or fall back on vague concepts such as "courage" - a quality that impresses other actors, I guess, more than it does audiences. As I watch him talking about Iceman, it occurs to me that the most distinctive and appealing aspect of Kevin Spacey's persona might simply be the obvious, completely unapologetic joy he takes in acting. There's something disarming about it, this innocent delight.

At one point in our poolside seminar on all things theatrical, Spacey tells an anecdote about John Huston on the set of The Night of the Iguana. One night, apparently, everyone was sitting around playing a game in which every person has to choose just one word to describe the most important thing in life. "Someone said 'beauty' and someone said 'wealth' and someone said 'family'. And when it came around to Huston, he said, 'Well, ladies and gentlemen, I'd have to say "interest" - to stay interested' And I think that's a great lesson." And just a few minutes later, I hear Spacey saying, "I want to continue challenging myself, to try to stay aggressively - uh, what's the word I'm searching for? [perfectly judged pause] Interested." I knew exactly what the word he was "searching for" was going to be, yet I find myself, somewhat to my surprise, charmed and pleased when it actually arrives, right on schedule. I also know he's telling me the truth, in his own way - maybe his best way. It's an actor's truth. And I say that with respect.