c. 1994 N.Y. Times News Service

PRINCETON, N.J. - Several weeks before the 1994 Nobel prize in economics was announced on Oct. 11, two mathematicians - Harold W. Kuhn and John Forbes Nash Jr. - visited their old teacher, Albert W. Tucker, now almost 90 and bedridden, at Meadow Lakes, a nursing home near here.

Nash hadn't spoken with his mentor in several years. Their hour-long conversation, from which Kuhn excused himself, concerned number theory. When Nash stepped out of the room, Kuhn returned to tell Tucker a stunning secret: Unbeknownst to Nash, the Royal Swedish Academy intended to grant Nash a Nobel Prize for work he had done as the old man's student in 1949, work that turned out to have revolutionary implications for economics.

The award was a miracle. It wasn't just that Nash, one of the mathematical geniuses of the postwar era, was finally getting the recognition he deserved. Nor that he was being honored for a slender 27-page Ph.D. thesis written almost half a century ago at the tender age of 21.

The real miracle was that Nash, 66, - tall, gray, with sad eyes and the soft, raspy voice of someone who doesn't talk much - was alive and well enough to receive the prize. For John Nash was stricken with paranoid schizophrenia more than three decades earlier.

Nash's terrible illness was an open secret among mathematicians and economists. No sooner had Fortune magazine singled him out in July 1958 as America's brilliant young star of the "new mathematics" than the disease had devastated Nash's personal and professional life.

He hadn't published a scientific paper since 1958. He hadn't held an academic post since 1959. Many people had heard, incorrectly, that he had had a lobotomy. Others, mainly those outside Princeton, simply assumed that he was dead.

He didn't die, but his life, once so full of brightness and promise, became hellish. There were repeated commitments to psychiatric hospitals. Failed treatments. Fearful delusions. A period of wandering around Europe. Stretches in Roanoke, Va., where Nash's mother and sister lived.

Finally, a return to Princeton, where he had once been the rising star. There he became the Phantom of Fine Hall, a mute figure who scribbled strange equations on blackboards in the mathematics building and searched anxiously for secret messages in numbers.

Then, roughly 10 years ago, the awful fires that fed the delusions and distorted his thinking began to die down. It happened very gradually. But, by his mid-50s, Nash began to come out of his isolation. He started to talk to other mathematicians again. He began to work on mathematical problems that made sense. He made friends with several graduate students. He didn't get a job, but he started to learn new things, like using computers for his research.

And here he was at Meadow Lakes. Within a few weeks, Nash got the early morning telephone call from Stockholm - 45 minutes late, as it turned out - telling him that he was being honored along with two other pioneers of game theory, John C. Harsanyi of the University of California at Berkeley and Reinhard Selten of the University of Bonn.

Alicia Nash, with whom Nash shares a home near Princeton even though the couple were divorced years ago and who was let in on the secret along with Tucker, breathed a sigh of relief. They called their son, also a mathematician, and Nash's sister to tell them the great news.

Later, there were champagne corks and a news conference, dry Nashian jokes about the prize money not being all that good (his share is about $310,000) and consultations with other Princeton laureates about the proper way to address Sweden's King and Queen when the award is presented Dec. 10. There was even an invitation to visit the White House, on Nov. 28.

On one level, John Nash's story is the tragedy of any person with schizophrenia. Incurable, incapacitating and extremely difficult to treat, schizophrenia plays terrifying tricks on its victims.

Many people with the disease can no longer sort and interpret sensations or reason or feel the full range of emotions. Instead, they suffer from delusions and hear voices.

But in Nash's case, the tragedy has the added dimensions of his early genius - and of the network of family and friends who valued that genius, wrapping themselves protectively around Nash and providing him with a safe haven while he was ill.

There were the former colleagues who tried to get him work. The sister who made heartbreaking choices about his treatment. The loyal wife who stood by him when she no longer was his wife. The economist who argued to the Nobel committee that mental illness shouldn't be a bar to the prize. Princeton itself.

Together they made sure that Nash did not wind up, as so many victims of schizophrenia do, a patient in a state hospital, a homeless nomad or a suicide.

Schizophrenia usually strikes people in their teens or early 20s, often without warning, just as they are about to spread their wings. Nash was struck when he had already begun to soar.

Schizophrenia is often confused with manic depressive illness, the disease that afflicted Vincent Van Gogh, Virginia Woolf and a host of other geniuses. But that illness, primarily a disorder of mood rather than of thinking, typically arrives later in life.

Sufferers can often hold high-level jobs and do extremely creative work between bouts. Schizophrenia, on the other hand, is too debilitating to co-exist with great accomplishment. Nijinsky, the Russian dancer, is one of the few known victims of schizophrenia other than Nash to have made his mark as a genius before the disease struck.

"It is always sad, but particularly when it involves someone as bright as he is," said John C. Moore, a retired mathematician who was close to the Nashes for 30 years. "These would have probably been his most productive years."

Nash has never talked about his illness publicly except to refer obliquely, at the news conference announcing his Nobel, to the fact that he had made some irrational choices in the past. He declined to be interviewed for this story, saying, "People know what they know."

But many of the people who have been close to him over the years or got to know him in the last few years have been willing, now that he has the extra protection of the mantle of a Nobel prize, to talk about his life and his achievements.

John Nash's West Virginia roots are often invoked by people who knew him at Princeton or at the Massachusetts Institute of Technology, where he taught for a while in the 50s, to explain his lack of worldliness. But Bluefield, the town where he grew up, was hardly a backwater. It had the highest per capita income in the state during the 30s and 40s and was home to a handful of millionaires, the Virginia Southern railroad and a four-year Baptist college.

Nash's mother, Margaret, was a Latin teacher. His father, John Sr., was a gentlemanly electrical engineer. By the time John Jr. and his younger sister were in elementary school, in the middle of the Depression, the Nashes lived in a white frame house, down the street from the country club.

Nothing was more important to the senior Nashes than supervising their children's education, recalls the sister, Martha Nash Legg. John Jr. was a prodigy but not a straight-A student. He read constantly. He played chess. He whistled entire Bach melodies. He invented things and conducted experiments.

"John was always looking for a different way to do things," said Mrs. Legg, a tall, handsome woman who is a potter in Roanoke. In elementary school, one of his teachers told John's mother that her son was having trouble in math. "He could see ways to solve problems that were different from his teacher's," Mrs. Legg said, laughing.

In the fall of 1945, Nash enrolled at Carnegie-Mellon, then Carnegie Tech, in Pittsburgh. It was there that the label "genius" was first applied to Nash. His mathematics professor called him "a young Gauss" in class one day, referring to the great German mathematician. Nash switched from chemistry to math in his freshman year. Two years later he had a BS and was studying for an MS.

His graduate professor, R.J. Duffin, recalls Nash as a tall, slightly awkward student who came to him one day and described a problem he thought he had solved. Duffin realized with some astonishment that Nash, without knowing it, had independently proved Brouwer's famed theorem. The professor's letter of recommendation for Nash had just one line: "This man is a genius."

In 1948, the year Nash entered the doctoral program at Princeton with a fellowship, the town was arguably the center of the mathematical and scientific universe. It not only had the Institute for Advanced Study and Albert Einstein, but also there was John von Neumann, the charismatic mathematician who helped develop the modern computer as well as the mathematical theory behind the H-bomb.

At once eager to prove himself and somewhat gauche, especially compared with older students who had served in the war, Nash quickly became one of the brilliant young men who performed mental pyrotechnics in the common room of Fine Hall. Soon after he arrived he invented an extremely clever game that was played with markers on hexagonal bathroom tiles. An instant fad in the common room, it was called "Nash" or "John." Parker Brothers brought out a version a few years later called Hex.

Other students found him a loner, odd as well as brilliant. When he wasn't in the common room talking a blue streak, he paced. Around and around he would go, following Fine Hall's quadrangular hallways, occasionally dashing into empty classrooms to scribble, with lightning speed, on blackboards.

"He was always an unusual person," said Jack Milnor, an undergraduate at the time and now a mathematician at the State University of New York at Stony Brook. "He tended to say whatever came into his mind."

Lloyd S. Shapley, then a graduate student and now a mathematician at the University of California at Los Angeles, added, "He was obnoxious. What redeemed him was a keen, beautiful, logical mind."

Nash's Nobel-winning thesis on game theory was the product of his second year at Princeton. Game theory was the invention of von Neumann and a Princeton economist named Oskar Morgenstern. Their 1944 book, "The Theory of Games and Economic Behavior," was the first attempt to derive logical and mathematical rules about rivalries.

The Cold War and the nuclear arms race meant that game theory was an idea whose time had arrived.

Characteristically, Nash picked a problem for his thesis that had eluded von Neumann. Briefly, von Neumann only had a good theory for pure rivalries in which one side's gain was the other's loss. Nash focused on rivalries in which mutual gain was also possible. He showed that there were stable solutions - no player could do better given what the others were doing - for such rivalries under a wide variety of circumstances.

In doing so, he turned game theory, a beguiling idea, into a powerful tool that economists could use to analyze everything from business competition to trade negotiations.

"It wasn't until Nash that game theory came alive for economists," said Robert Solow, a Nobel laureate in economics at MIT.

Nash got his doctorate on his 22d birthday, June 13, 1950. After brief interludes as an instructor at Princeton and as a consultant at the Rand Corp., the Cold War think tank, Nash moved on to teach at MIT in 1951.

He arrived itching to show that he could solve really big problems. According to one story circulating at the time, Nash was in the common room knocking, as he often did, other mathematicians' work. An older professor is said to have challenged him to solve one of the field's most notorious problems.

The problem grew out of work done by G.F.B. Riemann, a 19th century mathematician, and was considered virtually insoluble. But Nash wound up solving it. To do so, he invented a completely new method for approaching the problem that turned out to unlock a difficulty encountered in a far larger class of problems. Mathematicians still describe the solution as "astonishing" and "dazzling."

Most mathematicians consider this and other work Nash did in pure mathematics to be his greatest achievements, worthy of Nobels if such were given in the mathematical field. Many joke that he got his Nobel for his most trivial work.

Gian-Carlo Rota, a mathematician at MIT who is writing a chapter on Nash in his autobiography, said that Nash's results were so novel that they initially struck many people as incredible. "I heard Nash present his results on several occasions," said Rota. "Each time, somebody in the audience would say, "I simply don't believe a word of it.' "

By the mid-1950s, Nash was phenomenally productive. When he got tired of mathematicians, he would wander over to the economics department to talk to Solow and another Nobel laureate, Paul Samuelson.

And it was during this period that Nash met his future wife, Alicia Larde, an El Salvadoran physics student at MIT who took advanced calculus from him. Small, graceful, with extraordinary dark eyes, Alicia looked like an Odile in "Swan Lake." "Very, very beautiful," recalls Ziporrah Levinson, the widow of Nash's mentor at MIT, Norman Levinson.

"He was very, very good looking, very intelligent," Mrs. Nash recalls. "It was a little bit of a hero worship thing." They were married in 1957, a year Nash spent on leave at the Institute for Advanced Study.

By the time the Nashes returned to MIT, John Nash had been awarded tenure. Mrs. Nash went back to graduate school and worked part time in the computer center. In the fall of 1958, she became pregnant with their son, John Charles Martin Nash. "It was a very nice time of my life," she recalled.

It is just then, when life seemed so very sweet, that John Nash got sick. Within months, at age 30 in the spring of 1959, Nash was committed to McLean Hospital, a psychiatric institution in Belmont, Mass., connected with Harvard University.

"Robert Lowell, the manic depressive poet, was also in the hospital," said Isador M. Singer, who shared an office with Nash at MIT, where he is now a professor. "There was Mrs. Nash, sitting there, pregnant as hell. Robert Lowell was sounding forth. And there was Nash, very quiet and almost not moving."

He added, "I've had that picture in my mind for years. I focused mostly on his wife and the coming child. I remember thinking, "It's all over for him.'"

Psychiatrists who treat victims of schizophrenia ask people who haven't had the disease to imagine how they would feel if unseen voices shouted, if they lost capacity to feel or to think logically.

And what if on top of that, asks E. Fuller Torrey, a psychiatrist in Washington and authority on schizophrenia, those closest to them began to avoid or ignore them, to pretend that they didn't notice what they did, to be embarrassed by their behavior? And what if the treatment was ineffectual? That is what happened to Nash.

In the months leading up to his hospitalization, Nash became another person. He skipped from subject to subject. Some of his lectures no longer made sense. He fled to Roanoke at one point, abandoning his classes. He wrote strange letters to various public figures.

"It was very sad," said Shapley at UCLA, who ran into Nash from time to time. "There was no way to talk to him or even follow what he was saying."

The months at McLean did little to arrest the disease. "Schizophrenia is a brain disease," said Torrey, adding that it is "a real scientific and biological entity as clearly as diabetes, multiple sclerosis and cancer are."

But neuroleptics, the drugs that were used to treat some, but far from all, of the symptoms for the next several decades, were just coming on the scene. And psychoanalysis, which has since been discredited as a means of treating schizophrenia, was in vogue. The causes of the disease are still not known.

As absurd as it now seems, Nash's psychiatrists thought that Mrs. Nash's pregnancy was part of the problem and hoped that he would improve after the baby's birth.

"It was the height of the Freudian period - all these things were explained by fetus envy," said Mrs. Levinson. Martha Legg added, sadly, "In those days, it was all supposed to be the mother's fault."

In any event, Nash's paranoia intensified and he could no longer work. After resigning his MIT post, he went to Europe, wandering from city to city. He feared he was being spied on and hunted down and he tried to give up his United States citizenship.

His wife and colleagues began to receive postcards with odd messages, many concerning numbers. "I rode on bus No. 77 today and it reminded me of you," one read. Eventually, the Nashes separated and he moved to Roanoke to live with his mother.

For most of the next 20 years, Nash divided his time between hospitals, Roanoke and, increasingly, Princeton.

In 1963, Mrs. Nash divorced him but eventually let him live at her house. Nash was hospitalized at least three more times. Mrs. Nash, who never remarried, supported her former husband and her son by working as a computer programmer, with some financial help from family, friends and colleagues. "It was a pretty lean life," said Martha Legg.

Nash became a sad, ghostly presence around Princeton and a mysterious character, the Phantom of Fine Hall, in a novel set in Princeton's mathematics community, "The Mind-Body Problem" by Rebecca Goldstein (Penguin).

"Everyone at Princeton knew him by sight," recalls Daniel R. Feenberg, a Princeton graduate student in the 1970s and now an economist at the National Bureau of Economic Research. "His clothes didn't quite match. He looked vacant. He was mostly silent. He was around a lot in the library reading books or walking between buildings."

Alicia Nash believed very firmly, according to several people close to her, that Nash should live at home and stay within Princeton's mathematics community even when he was not functioning well. Martha Legg applauds her decision. "Being in Princeton was good for him," said Mrs. Legg. "In a place like Princeton, if you act strange, you're special. In Roanoke, if you act strange, you're just different. They didn't know who he was here."

Roger Lewin, a psychiatrist in Baltimore, agrees. "Some people are so disturbed that there is no way to get in touch with them, but for a significant group, compassion and receptivity of the surrounding community make all the difference."

Some former colleagues at Princeton and MIT tried to help with jobs on research projects, though very often Nash couldn't accept the help. Shapley at UCLA succeeded in getting a cash mathematics prize for Nash in the 70s. There were other forms of kindness, like getting Nash access to university computers or remembering to invite him to seminars when old friends turned up on campus. Still, the people who stayed in regular contact with him eventually came to believe that his illness would never end.

Then came what Kuhn calls "a miraculous remission." And as happens, for reasons unknown, in the case of some people with schizophrenia, it was not, according to Mrs. Nash or Mrs. Legg, due to any drug or treatment.

"It's just a question of living a quiet life," said Mrs. Nash.

The most dramatic sign of that remission, perhaps, is that Nash was able to do mathematics again.

And now Nash is a Nobel laureate. The story of his prize is itself testament not only to his survival but to the fierce loyalty and admiration he inspired in others.

During the 20-plus years of Nash's illness, game theory flourished and it is hard to find an important article in the field that doesn't refer to his work. But mathematicians and economists who were close to the secret deliberations say that the Nobel was hardly a sure thing.

By mid-1985, the prize committee was evidently actively considering an award for game theory. (The Nobel Memorial Prize in Economic Science is not one of the prizes established in the will of Alfred Nobel, but was created as a memorial to him in 1968.)

Five years later, the committee was making discreet inquiries not just about Nash's contribution but about his state of mind. There is no formal rule that a recipient must travel to Stockholm to accept the prize in person, give a Nobel lecture there or deliver a few profundities and words of gratitude to the King at the banquet. And there is certainly no rule that the recipient must hold a university post or have maintained an active career beyond the prize-winning contribution.

But no one wins prizes without an active constituency in his field. To most young game theorists who urged that he get a prize, Nash was a demigod. But Kuhn played a particular role. A noted game theorist himself, he made it clear to the committee that it would be a grave injustice if Nash's illness cost him the prize.

Early in September, Kuhn got a clear signal that the prize would go to Nash when he was asked to prepare a curriculum vitae for him and to provide some photographs. At the professor's suggestion, Princeton created the title Visiting Research Collaborator to provide a ready answer for Nash to the inevitable question of his current affiliation.

The reaction to the announcement was jubilation. "The main message to the world is that the academy says mental illness is just like cancer, nothing special," said Ariel Rubinstein, a game theorist at Tel Aviv University. "It's great."

What will Nash do now? At 66, he is past the age when most mathematicians do their best work. But the researchers he now talks to say that he is interested in the major unsolved problems and that he has learned to use the computer in ingenious ways.

"The truths Nash discovered were all very surprising," said Simon Kochen, another Princeton mathematician. "Nash is a man who surprises people."