If I were a rich man," sings Tevye, the milkman in Fiddler on the Roof and he dreams of a big house with one long staircase for going up, one even longer coming down and one more leading nowhere, just for show. He concludes with what his downtrodden soul needs most: honor.

To be rich is a fantasy. But the rich don't stop dreaming. Their fantasies flow onward and upward, and to them all projects seem possible.

Rich men's dreams are blueprints rather than castles in the sky. Not for them is the wistfulness of the I-would-if-I-could or the melancholy of the might- have-been. They are rich, after all, because they are can-do people. They gained because they ventured, and they venture because gain is their life. AARON GOLDMAN

Aaron Goldman's reputation is that of a savvy businessman who turned a small company into a corporation with $250 million a year in sales. Though retired from business, he maintains a downtown office. And, although he hates the term philanthropist, he is a well- known giver to a platter of causes.

But the burning passion of his life is to have a play of his staged, and what fascinates him are the complexities of organizing a theatrical production.

"A play is an act of creation," he says. "I have had essays and short stories published, and people say I have a nice writing style. But nothing compares with the excitement of having your play staged. A play is dead unless you see it. Reading a play is like reading a musical score. Isn't terrible to write a piece of music and not hear it?"

He has written nine plays, and one of them, A Cock for Asclepius, was given a staged reading by a group of actors in 1981, at Georgetown University, his alma mater. While he was still in college, two of his one-act plays were produced and one of them won a prize.

Goldman is slender, elegant, smooth. In college he planned to join the Foreign Service, but in 1934, the year he graduated, the Depression was on and U.S. consulates were being closed. While waiting for the State Department to resume hiring, he took a temporary job with Macke, as a manager of six people servicing 300 cigarette machines. He stayed as the boss for 42 years, eventually employing 10,000 people in the District and 22 states, and turning the company into one of the largest businesses in the Washington area.

"But I am no longer a businessman," he says, throwing his arms in the air. "My fantasy is that one of these days I'll get a phone call from a fellow who will say he is Roger. 'Roger who?' I'd ask. 'Roger Stevens of the Kennedy Center. May I call you Aaron?' 'All right.' 'Look Aaron, I apologize for taking this long to call you, but I just read your play and I think it's terrific. I want to produce it. Now. Tell me Aaron, when can we get together?'"

Goldman grins, pleased with his performance. He is a raconteur, and the conversation with Stevens is part of his repertoire. "I think in terms of dialogue," he says. "I think like a playwright."

At 69, Goldman is confident that his most recent work, The Bar Mitzvah of Harry London, will be produced somewhere in the United States. Last November he sent out copies to 20 theatrical companies, but, he was told, it takes anywhere from three to nine months before he can expect an answer.

"Art is long but life is short," he sighs. "But if there was a Grandma Moses, there could be a Grandpa Aaron."

He is willing to wait a year, he says. But if he receives no positive reply, he will stage The Bar Mitzvah of Harry London himself. "If I can give money to other struggling artists," he says, "why not this struggling artist?" And he points to himself with both thumbs. DANA HODGDON

At 59, Dana Hodgdon looks as if he were in his early 40s, and he has the passions of a man in his 20s: to excel with women and in tennis. He goes out with a woman nearly every evening, he says, and he plays tennis several hours a day to get a national ranking. "On a good day," he says, beaming, "I feel like a 12-year-old."

He inherited money, he says, then made another fortune as a security analyst and a real estate developer. But, he says, the five wives he divorced and the five children he sired have taken away most of his money.

"We men marry for romance," he says, with a man- of-the-world smile. "Women are much more practical."

Hodgdon comes from what he calls a distinguished Episcopalian family with revolutionary soldiers for ancestors. "But I turned my back on all that long ago," he says. "I got kicked out of Princeton three times. I never did finish college, but by the time I was 27 I had done everything: sold vacuum cleaners in California, worked on a sheep ranch in Texas. I wandered and moved and messed around a whole lot."

Nowadays he wants both respectability and adventure. "I can't do something I'd be disgraced by," he says, "and that rules out a whole lot of things." For years, his number one fantasy has been to make "a great, beautiful, erotic movie which is in no way similar to what others have produced. It should have the kind of stuff I enjoyed as a young man . . . I want to show the world that an erotic movie is legitimate."

Hodgdon has been working on the script for the past five years, he says, and he is two-thirds done. "Erotic movies now on the market demean women. But women will love my movie. I want to create a new genre of movies."

He admires Hemingway's masculinity, his buildup of tension, and, above all, his skill in constructing dialogues. "It's all in the dialogue," Hodgdon says.

But he doesn't like to think in terms of models. "What's going to happen is what interests me," he says. "The past bores me. I never go back. I am an anti-traditionalist."

He buys modern art whenever he finds something he likes, and he happens to have the cash. "It's the safest way to blow your money if you have good judgment--which you acquire after 30 years of buying art," he says. "One way or another you get paid for your good judgment."

Hodgdon hasn't had a 9-to- 5 type job since 1978, but his investments necessitate a lot of paperwork, which he hates. If it weren't for his financial concerns, he says, he would have finished his movie script a long time ago.

"Unless I can see my way clear six months ahead in terms of my investments, I can't write," he says, suddenly as tense as any writer with a writer's block. "Ownership is a drag. It's not what you own that matters, but what you enjoy." BARBARA MARX HUBBARD Daughter of a millionaire toy manufacturer, Barbara Marx Hubbard aspires to

lead the human race to the next stage of its evolution, which she defines as "the realization of our potential as a universal species, co- creative with God." She believes that the alternative to "our maximum systems crisis of a nuclear Armageddon" is "a second, planetary Pentecost" in which "enough people will believe that we are one."

Hubbard's messianic intensity is muffled by an upper-class aplomb. The tailoring of her clothes and phrases is impeccable; no matter how unusual her statement, she can carry it off. At 51, she suggests a gray-haired Jane Pauley, a low-key Billy Graham. "I'm neither young nor old, but ageless," she concludes her autobiography, The Hunger of Eve. "I'm reaching for the Tree of Life." She is beyond chutzpah.

She says that she is "perhaps the most intense of the Americans who inherited wealth and have a vision for the future." She has thought of running for president; once she approached Sargent Shriver with the suggestion to serve as his vice presidential running mate. But, she says, she was inhibited by her "sense of feminine inadequacy."

Thrilled by space exploration, she calls the lunar landing "a warmup for the planetary Pentecost." She has volunteered to be a passenger on the space shuttle. "They should select me," she says, "because I could make space travel a meaningful experience. Space travel needs to be celebrated as a hope for the world."

Hubbard says she "adored" her late father, Louis Marx, known as the toy king of America. But, she says, he was "the last generation of self-made tycoons" and she, the oldest of his nine children, "couldn't do what he was best at. I had to find a new challenge.

"Our generation of Americans who inherited wealth is a pivotal group. We are a special gene pool of the most successful risk-takers of the world. We are all children of people who left the Old World, and we are all nationalities. We inherited the dream of ages, the dreams of Western civilization."

Hubbard has published a shelf full of booklets and tape cassettes, has founded and funded a raft of futurist groups, and has organized a nationwide series of interdisciplinary conferences with experts such as Buckminster Fuller and Jonas Salk. She recently created a 13-part TV program, titled "Potentials," in which she interviewed Ray Bradbury, Norman Cousins and Dr. Timothy Leary on issues ranging from brain research to a "peace-making army."

After her five children were grown and she divorced her painter husband, Hubbard established her headquarters in a stone mansion in Rock Creek Park. She has a staff of five fellow futurists--"a communications community."

"I am on the threshold of great events," she says with an air of girlish enthusiasm. She says she looks forward to meeting each visitor because she thinks of the parable of the 100th monkey: One by one, 99 monkeys learn a new trick such as washing sweet potatoes to get rid of the sand, but when the 100th monkey learns the trick, somehow, from then on, all monkeys wash their sweet potatoes--and that becomes an evolutionary change.

"The 100th monkey is on the way," she says. AL VAN METRE Engineer by training, land surveyor by experience, builder by choice, Al Van Metre lives his fantasy of being a sailor. He bought his first ocean-going racer in 1966 and has been winning all the big races ever since.

His current boat is the 61- foot-long, black-hulled Running Tide. "It's the fastest in its class," he says. "I haven't seen one that's faster." He won what he calls "the big ones"--such as the Bermuda and the Annapolis-to-Newport races--so many times that he has lost count.

He may not have more prizes to conquer, but he won't stop racing. "It's a terrible responsibility to go out there and continue to win," he says. "You don't get to relax. When new boats come into the Bay, they always want to know how they would do against Running Tide. It puts a terrific strain on us."

"Us" refers to Van Metre and his son, christened Al 36 years ago, but known as Beau.

"I began racing in order to teach my son how to handle people--Running Tide has a crew as big as 20--and to operate the logistics of a large enterprise," Van Metre says. "When we started racing, it was 80 percent of me and 20 percent of him. Now it's more than half him. He is probably the best starting helmsman in large-boat racing. He almost always wins the start."

Van Metre Senior has a brushlike shock of white hair and beard to match. His visage is that of a tough, laconic sea captain's, ageless at 56.

Going to sea is a Van Metre family tradition. His father was a commodore in the navy and his grandfather, a four-star admiral. Plenty of uncles and great-uncles of his served in the Navy.

He is thinking of buying an 80-foot maxiboat--the biggest allowed in racing. Running Tide, built in 1970, is getting old, though it is constantly worked on. This winter, its cockpit and steering are being refashioned, and the bill, Van Metre reckons, will run up to $60,000.

"It's a very expensive hobby," he says. "We sail because we enjoy it. A lot of macho types are out there, and some who do it for social sport. We tary Penstay away from the parties. Sometimes it's lousy as hell. It's wild out there. But I don't go out there to knock my head off. I'd like it easier. I like pleasant racing. But we do best when others founder in heavy winds. We won this fall's Annapolis race --the third or maybe the fourth time--in 40 knots of wind. You see other boats falling apart in bad weather, losing masts. But not Running Tide."

Van Metre calls Running Tide "a spartan boat, a racing machine," but he also owns a 71-foot powerboat, called Silver Seas, which he runs with his wife, Joan. He says he wants to do more cruising, with only him and his wife aboard, and visit European and Asian ports.

His construction firm has between 200 and 600 employes, he says, and nowadays he is away at sea for about a total of four months a year. He'd like to make that six months. Maybe more.

Asked if he is thinking of retiring from either building or sailing, he laughs. "Retire? I see my son moving into racing, myself into cruising. I'll never retire."