(CNN) -- Call him Phil.
That's what most people did. It was "Phil," not "Philip," and certainly not "Philip Seymour." (He used the Seymour because there was already an actor named Philip Hoffman, and union rules prevent two actors from using the same exact name.)
He didn't stand on ceremony. At the LAByrinth Theater Company, where he was an artistic director (and where his longtime partner, Mimi O'Donnell, has the same post), he involved himself in fundraising, directing, acting -- whatever it took.
"I've seen him tear tickets and seat people at LAB productions," playwright John Patrick Shanley told The New York Times Magazine. Shanley, also involved in LAB, wrote the play "Doubt," which featured Hoffman in one of the lead roles.
In Atlanta, where he was filming the final two "Hunger Games" movies, a local remembered an easygoing, gracious man.
"He was really soft spoken and kind," real estate agent Carter Phillips told the Atlanta Journal-Constitution. "I had this idea that he would be really intense, maybe, but no. I couldn't see any turmoil in his eyes. I felt like everything was right on with him."
He liked to work. When he wasn't starring in a movie, he was taking a small part. When he wasn't making films, he was in theater. If he wasn't performing, he would have been a teacher, he told "Inside the Actor's Studio" in 2000.
He had memories of times when he wasn't acting -- or working -- at all.
"Being unemployed is not good for any actor, no matter how successful you are," he once said. "You always remember what it feels like to go to the unemployment office, what it feels like to be fired from all those restaurants."
Acting was his home. He knew it as a 12-year-old watching Arthur Miller's "All My Sons" in his hometown of Rochester, New York, he said in a 2010 interview.
"Immediately I knew it was a place I wanted to be," he said. "Being around people who were doing that. ... That's still kind of what makes me feel comfortable. That's why I've worked with a lot of the same people over and over again."
At the time, Hoffman -- one of four children of a Xerox staffer and a judge who divorced when he was 9 -- was more of an athlete, a three-sport participant. But a neck injury at 14 dashed his sports dreams. Instead, he hit the stage. Of course, it wasn't all about greasepaint and cheers, he admitted to The New York Times Magazine.
"There was this beautiful girl. I had a huge crush on her, and she acted," he said. "It seemed like something worth giving up baseball for."
But he was good at acting. He passed an audition to a New York state arts program, where he met Bennett Miller, who became a lifelong friend and later directed him in "Capote". Later, attending NYU, he took in all the theater world had to offer.
"You're really part of the city. The theater is all around you, and if you want to rub your shoulders against it, you can, and if you want to try for usher jobs, or internships at working theaters, you can. And I did all that," he said.
His other home was with his family. He met O'Donnell, a costume designer, at LAByrinth. The pair had three children: Tallulah, Willa and Cooper. His children were all younger than 11.
He doted on his children. He was regularly seen with them in his Greenwich Village neighborhood. He brought them to work.
He noted they were unimpressed, especially with movies.
"Movies are difficult. 'Why are we in this warehouse? Why aren't there seats? Isn't this supposed to be a show?' " he recalled them asking. "I've taken them and they watch for a bit and it's like, 'Yeah, great Daddy, that was neat. Now -- can we please go home?' "
'That's what you do'
Still, there was obviously a darkness to Hoffman that came through with his intensity. Describing "Synecdoche, New York," to the Times Magazine, he said, "I'd finish a scene, walk right off the set, go in the bathroom, close the door and just take some breaths to regain my composure."
In an appreciation, New York magazine film critic David Edelstein recalled how Hoffman seemed to revel in the unpleasant aspects of his characters, something Edelstein noticed in 2005's "Capote." Hoffman apparently fought director Miller -- a friend, mind you -- to make Truman Capote more difficult, not less.
"Ever since then, I've been conscious of how much he went out of his way to make his characters unbenign," wrote Edelstein. "It was central to his power as an actor, though I wonder if at times he didn't confuse self-hatred for integrity."
Hoffman could also be hard on himself, Edelstein added -- and Hoffman, in other interviews, agreed. While making 2010's "Jack Goes Boating," his feature directorial debut, he told an interviewer at the Toronto film festival that he was his own worst critic.
"I was a bad actor in front of me a lot," he said. "There were some days when it was real dark."
In recent months, he'd had his share of challenges. He was up front about his struggle with drug abuse, telling TMZ last year he'd gone to a rehab facility after falling off the wagon. According to the UK newspaper The Independent, he and O'Donnell had separated last fall after 14 years together. Observers commented that he looked disheveled at the Sundance Film Festival in January, though Vanity Fair's Krista Smith described him as "present and engaged."
But if anything was wrong, he kept it to himself. For all his familiarity and politeness, he could be guarded. He left it all on set or on stage.
In that 2010 Toronto interview, with a touch of black humor, he talked about how hard it was to keep pushing the boulder up the hill. Why do "Othello," he asked. Why put yourself on stage for hours, convinced you're terrible, and wait for the approval -- or disapproval -- of the audience?
Because that's what makes it worthwhile, he said.
"That road to death we call life can be just burgers and booze and women and smokes and TV and magazines and really bad arts, and you just go and slide right into the hole," he said. "Or you can go, I think I'd better keep confronting and keep challenging and keep trying to make good stuff and working hard. ... That's what you do. If you don't do that, it's so easy to go to that other place."
On her Facebook page, Jessica Chastain, who co-starred with Hoffman in a 2009 production of "Othello," could only quote from that Shakespeare play.
"The poor soul sat sighing by a sycamore tree, Sing all a green willow. Her hand on her bosom, her head on her knee, Sing willow, willow, willow. The fresh streams ran by her, and murmur'd her moans. Sing willow, willow, willow. Her salt tears fell from her, and soften'd the stones. Sing willow, willow, willow."
Breeanna Hare contributed mightily to this story.