As a biographer of Hollywood celebrities, Arthur Marx knows how hard it is to get to the truth.
"Celebrities never tell the truth," he says, "at least not the whole truth."
Marx regards their reticence as an occupational hazard. His own father, the late Groucho Marx, once threatened to sue him to stop publication of "Life With Groucho," his intimate biography of the ad-lib master.
"He had a problem with that book even though it was very complimentary," Marx says.
The 74-year-old author, who appears tonight at the Curtis Theatre in Brea in "An Evening With Groucho and Son," has written seven star biographies, two novels, a collection of short stories, a Broadway play and an autobiography.
"It's not so much that I didn't want their cooperation, but I knew they would lie," he said in a telephone interview from his Bel Air home, not far from the Beverly Hills neighborhood of his youth.
He was reminded of their willingness to sanitize and fudge by a recent interview he did with Jack Nicholson for the cover story of a posh magazine.
"The magazine asked for a profile with details about his life. So I kept saying, 'Tell me how you got started.' He didn't tell me much. I said, 'Tell me about your parents.' He didn't tell me much of that either.
"When I finally got through with him, I had a lot of stuff on tape, but it wasn't what I needed. I had to find an unauthorized biography that came out last year. All the stuff he wouldn't tell me about--being an illegitimate child and not knowing his 'sister' was really his mother--was in it. Yet he said he was trying to be honest with me."
Marx was always encouraged to be a writer by Groucho. "He didn't want me to be an actor, and he wanted to be a writer himself," Marx said. "He was always looking over my shoulder."
Even so, when Marx wrote his father's biography, his usually helpful father was less than enthusiastic.
Marx tended to show Groucho what he was writing. But with "My Life With Groucho"--first published in 1954, updated and enlarged in 1992--he didn't let him see the manuscript until the Saturday Evening Post had bought it for serialization.
"When I did show it to him, figuring he would want to correct it, he got mad," Marx said. "He went to his lawyer and everything. He threatened to sue me to stop it. He scared the hell out of me. I had to hire my own lawyer to bluff him out of it."
Groucho was mollified when Marx's publisher sent him a set of galleys for final corrections.
"He made some minor changes--nothing major," Marx recalled. "He was just being a father. I threw his galleys into the wastebasket. He never knew the difference."
Marx's maxim about celebrities withholding the truth was proved to him for the first time by his own father.
It wasn't until after "Life With Groucho" was published that Marx learned, for example, that a lot of his father's ad-libs on "You Bet Your Life," Groucho's popular TV quiz program of the '50s, were written for him.
Marx discovered that only when a friend told him years later that he'd been offered the job of writing the ad-libs.
"My father never told me that himself, even though he had helped me out with plenty of information," Marx explained. "In the early days of that show, lots of the contestants were deadly. They took the contestants right out of the audience. As good as he was at ad-libbing, he couldn't get good jokes off of them.
"So they finally devised the idea of interviewing contestants first. The writers would put down [the contestants'] funny remarks on paper, and the best contestant would get on the show. My father would have a copy of what they were going to say. It was like a transcript. He knew ahead of time what they were going to say."
Marx was the proverbial starving artist when his first book--"The Ordeal of Willie Brown," a novel about the amateur tennis circuit--was published.
"Why don't you become a director?" his father advised him. "You don't have to have any talent to be a director."
Was Groucho kidding?
"No, he believed it," Marx said. "He didn't think his directors were any good. He didn't like Leo McCarey, who did 'Duck Soup,' or Sam Wood, who did "A Night at the Opera."
Both pictures were among the Marx Brothers' best comedies, despite Groucho's opinion of Wood and McCarey, and were made during the early '30s at the peak of their Hollywood career.
Did Groucho have a favorite picture?
"He thought 'A Night at the Opera' was the best one," Marx said. "He liked 'A Day at the Races' next. He thought 'Duck Soup' was funny, but he was disillusioned with it because it didn't make any money." Lengthy clips from "Duck Soup" will be shown at the Curtis Theatre, along with others from "Horse Feathers" and "Monkey Business," as well as the screening of a full-length comedy that hasn't been announced.
* Arthur Marx appears for "An Evening With Groucho and Son" tonight at the Curtis Theatre, 1 Civic Center Circle, Brea. 7 p.m. $10.50. (714) 990-7722.