A FEW DRINKS DOWN, Julian Simon stood at the bar between the kitchen and the sun room of his host's home and mixed a gin and tonic. Bourbon, he reasoned, might stain Paul Silverman's coat and tie.

"This misrepresentation by Professor Simon has no claim on scholarship."

Silverman's biting words of a few days before still rang in Simon's head. The SOB! Silverman had attacked Simon before 2,000 people at the Earth Day 1970 teach-ins at the University of Illinois, where both men taught. He'd accused Simon of virtual ignorance in Simon's claims that Earth Day's doomsdayisms about resources and population were hogwash.

Ambush in academe!

Simon stood at the bar, contemplated his retort, and glared at Silverman, an internationally respected zoologist, as he circulated through the cocktail party, chatting with the 30 or so guests who drifted in and out the french doors to see the magnificent sunset.

Simon had been going around campus saying that the world's 3 billion people didn't put the Earth near its carrying capacity -- it could carry 30 billion people!

Preposterous! Silverman believed. His critique of Simon was personal and sarcastic: "Now, this is a monumental piece of scholarship" . . . "this remarkable prediction technique is worthy of at least a Nobel Prize" . . . "numerous unsupported assertions." Silverman gave the litany of horrors: toxic pollutants, lead, fertilizer and heavy metal poisoning, thermal pollution, impending oil depletion -- all exacerbated by a world doubling its population every 15 years. Silverman asked how Simon -- a mail-order marketing expert, for God's sake -- could dispute the conclusions of hundreds of well-meaning scientists. " . . . unless, of course, he's convinced that the economics of a stable society threaten the mail-order business."

Below the belt, Simon fumed, below the belt. From the cocktail party bar, Simon watched Silverman approach. Target in range and closing, about five feet -- Simon launched his rebuttal: A gin and tonic to Silverman's face. The astounded guests cluck-clucked. Silverman wiped his face with his handkerchief and walked away.

Simon rearmed, and launched a second gin and tonic. Silverman walked away, through the french doors and onto the grass just beyond the brick patio -- where Simon found him again and unloaded still a third gin and tonic. Provocation complete, the professors scuffled like schoolboys, until an economist and a zoologist led Simon away. Too late: The intellectual war of Julian Simon was launched.

IT IS 15 YEARS LATER and the 53-year-old Julian Simon -- "one more small-town nut," as he describes himself -- is a celebrity on the political right. As embattled point man for a new orthodoxy, Simon has ruthlessly unmasked the flaws in a generation of unchallenged wisdom. His brash persistence, the power of his argument, and changing times disarmed the rhetoric of the Population Explosion.

Right or wrong, Simon has made a difference -- last year the Reagan administration used Simon's once denigrated views to alter its Third World population policy, which for decades had assumed that rising numbers of people undercut economic progress.

"I'm an 'aginner,' perverse way of, 'You say black, I say white.' But I'm not for it just because that's what's going down." And no doubt, on Earth Day, April 22, 1970, there was a powerful tune coming down: The world is going to hell in a handbasket.

Who could dispute it? DDT everywhere; petroleum, zinc, copper dwindling; falling crop yields. But worst of all, people -- "untrammeled copulation" in the Third World threatening a new Stone Age of famine and disease.

"The battle to feed all of humanity is over," biologist Paul R. Ehrlich intoned in the 1968 call to arms, The Population Bomb.

As Earth Day unfolded on 12,000 high school and college campuses, as notables from Ren,e Dubos to Richard Nixon harmonized to environmental woe, the obscure Illinois professor Julian Simon stood up and said it was mostly hooey. The world was not bad and getting worse -- people lived longer and healthier lives. The air was not getting dirtier, but cleaner. And resources weren't dwindling -- they were more plentiful.

Simon, his private life's goal to uncover ideas -- any ideas, really -- that would change the course of history, became the heretical high priest. He argued that more people -- even millions added to already poor millions -- are good in the long run. He was called a crackpot. Yet his ideas threaded their way through the erratic machinery for sifting truth in the political and academic worlds. Simon became a darling of neoconservatives. The media spotlight that helped create the population "crisis" eventually focused on Simon's equally novel views. A full hearing was assured in 1981 when Princeton University Press published Simon's doomsday debunking book The Ultimate Resource. Simon's resource was people.

Today, the cycle is nearly complete: A special committee of the National Academy of Sciences, committee researchers say, will this fall report that population growth is almost never the most important key to Third World economic success or failure. The $350,000 review, say several experts working on the report, came about because Julian Simon would not shut up.

The dominant view is still that rising population is a profoundly serious world problem and that fewer babies would be better. Mainline economists, whose respect Simon desires, today credit Simon with forcing a sweeping shift in thinking on population, but many still are niggardly in their kudos: Simon's work, they say, is provocative, but superficial. And some experts still agree with Paul Silverman -- preposterous!

"My salvation, my strength was that I could go for 10 years without people loving me," says Simon. "I could continue doing things that would bring no comradeship, no love, affection, admi- ration, because I never really expected that from the world anyway."

IT IS LIKE an Optimist Club meeting for social scientists.

The June conference of the conservative Child and Family Protection Institute at Washington's Hyatt Regency Hotel brings together upbeat experts who, science aside, promote loyalty, chastity and honesty within the American family. Not surprisingly, Julian Simon is a speaker. Not surprisingly, the audience is sympathetic.

"Why do the papers harp on the scraps of bad news?" Simon asks.

He is a short, athletic man, a regular squash player, with a taut body in a loosely tailored dull green suit with cuffs. He began shaving the rim of his bald head 15 years ago, and he has acquired the habit of smoothing hand over scalp serenely as he thinks or listens or talks. It is perhaps his only serene feature.

He speaks quickly. His hands don't so much wave as jerk ungracefully about him. He exchanges farsighted for nearsighted glasses several times during his speech. Simon gets off easy today -- the questions are upbeat.

For the hour-long talk, Simon will earn $1,000. He is a business and social science professor at the University of Maryland, an adjunct scholar at Washington's conservative Heritage Foundation and at the libertarian Cato Institute. Simon is hot -- and no one is more surprised than Simon.

"Up to 1980 I couldn't even round up a couple of loafers on a corner to hear what I had to say," he laughs. This can't last, thinks Simon, always cheerfully pessimistic about his own future.

The week after he arrived at Maryland a letter in the school paper called him an embarrassment to the university. "I'd been here two weeks!" he says.

Simon loves this story. It confirms his identity: iconoclast. From Simon's favorite philosopher, William James: "Sow an action and you reap a habit; sow a habit and you reap a character; sow a character and you reap a destiny." No doubt, themes recur in Simon's life. Blue-collar Jewish kid among middle-class New Jersey goyim. An unrebellious boy, but the best friend of a neighborhood gambler's son. Navy ROTC scholarship student at Harvard in the '50s, when the sons of America's elite really knew "what to wear on their feet."

As a young man, Simon drove a taxi and sold encyclopedias. He worked in tin can and grass- seed factories, clerked in a drug store and painted signs. Simon's vita lists those jobs -- along with more than 150 academic articles and 18 books.

And there was his father, Philip Simon, who ran a small washing soda business. War shortages put his business under in 1942, and before his recent death, Philip Simon, who had arthritis, never really worked again. Simon's father was autocratic and the boy would take to the library to defend even casual kitchen-table opinions -- whether air conditioning was good or bad for the

health, for instance. Simon's mother, a "tough-minded woman" with "no sympathy for small failings," often intervened in Julian's behalf. No matter really, Philip Simon could not tell fact from opinion.

"There was never any belief in me," says Simon, "that I could ever persuade him that anything was so or that I had a claim." Simon is blunt: He came to feel nothing for his father. "The thing he could do is say his prayers faster than anyone . . . ," Simon says softly. "I clearly didn't like my father."

Key childhood lesson: People with power abuse it.

Simon was always uncomfortable and uninterested in "shmoozing." He was introspective and resentful of authority, always in hot water with some boss, especially in the Navy, where he was busted from several jobs -- unfairly, he believed. "I don't trust any authority to have my interests at stake," he says, "or to even give me a fair shake."

Key lesson from the Navy: Institutions abuse power.

What Simon loved was ideas; making a lasting intellectual contribution became his obsession.

"I used to think, 'What are the things in me that are worth anything?' And the things that are mostly worth something are my ideas and my capacity to work hard . . . What am I worth? I'm not sure I'm worth very much. I never thought of myself as being a terrific spouse or parent. I never took it for granted that my kids would love me. Now I'm convinced that they do, but that's a Johnny-come-lately idea. I was always uncertain: Why the hell should they care about me that much? . . . Some people walk around and think they're just, that lovely phrase, 'God's gift to the world.' Just in terms of their person, and I never felt that."

Simon earned a PhD in business economics at the University of Chicago. After running several small mail- order businesses in New Jersey, he began teaching advertising and later marketing, business and economics at Illinois. He fell into a deep depression, and over the years came to see his achievements as small. "Death was not unattractive," he once wrote. Only when he had an idea he believed might change society did he really come alive. Night after night, he sat on the sofa: "Where can I make a contribution?"

Then in 1965, Simon read a newspaper article about world population growth: It took 2,000 years for the Earth's population to rise from 500 million people at the time of Christ to 2 billion in '65 -- and it was expected to double to 4 billion in the next 13 years! Simon was saved: "I enlisted in the great fight to reduce births."

But when Simon began research for an academic book on population and economics, his faith in the accepted wisdom faltered. He discovered that research by economists Simon Kuznets, a Nobel laureate, and Richard Easterlin revealed no link between population growth and economic health. He learned from economist Ester Boserup that rising populations had pushed nomadic tribes into the progress of settled agriculture. He learned from economists Harold J. Barnett and Chandler Morse that despite cries of resource shortages, resource prices had steadily dropped.

While in Washington to promote a scheme to control population in India, Simon was suddenly struck with his supreme arrogance: "Have I gone crazy? What business do I have trying to help arrange it that fewer human beings will be born, each one of whom might be a Mozart or a Michelangelo or an Einstein?"

Key lesson: experts, too, can abuse their power.

POPULATION WAS not the frenetic Simon's only interest. His book, How to Start and Operate a Mail-Order Business sold more than 100,000 copies. His idea to let airline passengers give up their seats on overbooked flights in exchange for free tickets -- rather than be bumped arbitrarily -- was adopted by the Civil Aeronautics Board. On the side, Simon wrote a 300-page manuscript, still unpublished, about how people can fight off depression, based on his own experience.

In 1977, Princeton University Press published Simon's The Economics of Population Growth, which argued that rising numbers of people always spur economic growth. Resounding silence. Simon would go to professional meetings, and colleagues would stare blankly at his name tag.

"What absolutely drove me out of my skull was hearing an Ehrlich for an hour on Johnny Carson," Simon recalls. "Knowing that there was no way that I could say any word to anybody." Then Simon remembered reading that economist John Kenneth Galbraith had popularized his ideas to force economists to pay attention to him. Simon took the lesson.

He sent an article debunking the environmental Cassandras to Science magazine, the journal of the American Association for the Advancement of Science, and to his amazement it was published. The article brought as much scientific criticism as any ever appearing in Science, says then-editor Philip H. Abelson, who adds that he wouldn't run the Simon article again today because "it doesn't wear as well as I would prefer."

No matter, Science gave Simon instant legitimacy. Dozens of magazine and newspaper articles followed, Princeton published The Ultimate Resource, and Simon edited the semiofficial rebuttal to the Carter administration's Global 2000 report, which predicted impending environmental calamity. Nobody stared blankly at Julian Simon's name tag anymore.

Forever the outsider, the success also saddened Simon: "So it came out. And one thing leads to another. The rich get richer. Those with access get more access." Princeton never would have published The Ultimate Resource, Simon says, if the Science article hadn't run -- and it could just as easily have been killed. Simon credits not so much himself, but coincidence. He recalls a Jewish prayer: I've been young and I've been old, and I've never seen a righteous person forsaken. "For years," he says, "I've always said in Hebrew, 'Nonsense.' THE ULTIMATE Resource was a broadside: World food production is up, not down, wrote Simon; natural resources are cheaper than ever; technological innovation has almost always kept well ahead of isolated food and resource shortages; famines and crop failures have more to do with politics than population. If the world is better off today than 20 or 200 years ago, how can people be bad?

More people means more pressure for creative thinking in resources, education, technology. A healthy free marketplace, Simon argued, is the key. The so-called experts can't predict what breakthroughs will solve, say, world energy needs tomorrow, any more than England's 19th century experts could predict that oil would replace coal.

Worst of all, Simon proclaimed, the mistaken paranoia about the Population Explosion justified coercion -- and led to dictatorial birth policies like that of China, where familes are allowed only one child.

"I do not say that all is well," wrote Simon, who supports voluntary family planning and legal abortion, though he personally abhors abortion. "Children are hungry and sick . . . war or some new pollution may do us all in. What I am saying is that for most of the relevant economic matters I have checked, the trends are positive rather than negative. And I doubt that it does the troubled people of the world any good to say that things are getting worse though they are really getting better."

The response was predictably harsh. "It's like physicists arguing for a flat Earth," says environmentalist Paul Ehrlich. Says ecologist Garrett Hardin: "Tomorrow has come for Ethiopia."

"I don't see how you can argue population growth is good when people are living in ghettos . . . ," says Richard Rennick of The Population Institute. "Ninety-two percent of the population growth is occurring in underdeveloped countries and it is devastating their economies. That's where we're coming from."

But those answers didn't fly as well as they did on Earth Day. "There aren't any data to go out and make a case that population growth has any serious negative effect on economic growth . . . ,' says University of California economist and demographer Ronald D. Lee. "I also would say there is no evidence to show it's beneficial. It doesn't really show that it matters very much."

This is now mainstream economic wisdom -- and it's news to people raised on the economic evils of the Population Explosion. It doesn't mean, however, that economists believe Simon's work is seminal. Several experts working on the National Academy of Sciences committee investigating the link between population and development say there also is no evidence that population growth is always good, as Simon argues.

"His belief in more minds is such a tremendous oversimplification . . . ," says World Bank senior economist Timothy King. "It's not that it's totally, totally wrong, but taken to its conclusion it's absurd. If it were true, Bangladesh would be better off than France."

Yet being all right or all wrong isn't really the issue in the battle of ideas. "The pendulum is swinging back to the middle," says Robert J. Lapham, study director for the still-unreleased NAS report, "and I see a new consensus emerging from what Julian has been writing."

AT THIS GARDEN party, Julian Simon is the guest of honor.

The Cato Institute hosts the July reception on Capitol Hill to celebrate his new book on immigration. Simon argues that immigration, legal or illegal, is always good for the United States. Once again, Simon has seized the publicity high ground.

At an immigration policy round table for congressional staffers before the reception, immigration expert David S. North -- echoing other voices from over the years -- had accused Simon of going too far in generalizing from the narrow specifics of North's own research. But other panel experts were effusive. "When the history of our science is written," said Thomas Espenshade of The Urban Institute, "Julian Simon will rank among its most creative and iconoclastic thinkers."

The remark has touched Simon. He says: "I remember reading some scientist once saying that all of human endeavor is a kid sitting on the beach saying, 'Look at my sand pie!'eception. But still, such comforting climes make him uncomfortable. He remembers his first book party for The Ultimate Resource: Everyone was standing around congratulating him, but he felt strangely out of place. Then a man dressed completely in black stood up: "That man's a fraud!"

Simon could feel himself change, turn on, get comfortable, as he shifted from insider to outsider, the true source of his strength and insight. Sometimes he does feel weary in a way he didn't years ago. He worries that he is losing his edge. What is the message of his work? "We can sit down and relax and enjoy the afternoon," he says. Everyone, that is, except Julian Simon.

The Reagan administration last year at the U.N.- sponsored International Conference on Population in Mexico City drew on Simon's ideas in its official policy linking free-market economies with effective population policy and denying worldwide population growth was itself a crisis. And Simon's immigration book has made him hot again. Yet he isn't satisfied: His contribution is so small.

Perhaps his most lasting work, Simon says, will be his idea, called the Monte Carlo Method, to computer simulate statistical calculations now performed through complicated formulas. Simon hopes his Monte Carlo Method will end up in the head of every high school student someday. And his 1970 article on causality hasn't gotten much attention yet, but he believes it is the biggest jump in thinking on cause-and-effect since the work of 18th century philosopher David Hume. Simon, working the reception crowd of about 50 guests, stops to thank Tom Espenshade for his unexpectedly laudatory comment at the round table.

"I didn't say he was right," Espenshade says after Simon walks away. "I said if he is right." The Princeton-trained economist believes Simon is a truly creative thinker, but he too believes Simon often goes too far in drawing conclusions from too little data. If Simon knew his colleagues respected him, Espenshade reasons, perhaps he wouldn't be so extreme.

"Don't you think?" he asks Simon critic David North.

In North's briefcase that day is a copy of his article, "The Missing Tallies in Julian Simon's Work." North looks at Espenshade, frowns, smiles and gives a skeptical shrug.