By David Warsh

Perhaps you'll see ''A Beautiful Mind,'' a film about a brilliant mathematician befogged by paranoid schizophrenia, sheltered by a long-suffering wife, until he achieved the professional recognition he deserves. The story was adapted from Sylvia Nasar's full-length biography of Nobel Memorial Prize in Economic Science laureate John Forbes Nash Jr. 

The movie simplifies the life, of course. It assigns to Nash an interest in fighting the Cold War that he did not possess. It omits his homosexuality - no one wants to see actor Russell Crowe busted by the FBI coming out of a Santa Monica lav. The script finds no way to depict the shameful attempt that Nasar uncovered to block the award of the prize in 1994. 

Nor, aside from a few broad assertions at the end that Nash's work had turned out to be important, does the film have much to say about the work that led to the Nobel Prize. What was it that John Nash actually did? A forceful answer to that question was propounded a couple of years ago by Roger Meyerson of the University of Chicago in the Journal of Economic Literature. Now his argument has been incorporated into a graceful introduction by author Nasar to ''The Essential John Nash,'' a companion volume to the movie. 

Meyerson assigns Nash an absolutely central place in the history of economic thought - ahead of much more familiar 20th-century economists, such as Keynes and Schumpeter, Samuelson and Friedman. The basic concept that bears his name - Nash equilibrium - is as ''fundamental and pervasive'' to the social sciences as is the discovery of the double helix structure of DNA to the biological sciences, he writes, because it unlocks the hidden structure of social interaction. 

Before Nash published his dissertation on ''Non-Cooperative Games'' in 1950, Meyerson says, mainstream economics had been relatively narrowly conceived as being about the production and distribution of material goods. Afterward, economists slowly came to see they now possessed a framework for analyzing incentives in all social situations, not just those involving money and markets - war and peace, crime and punishment, voting and coalition building, love and despair. They just had to learn how to use their new tool. With the wisdom of a half-century of hindsight, the film illustrates an optimal dating strategy among five co-eds, one of whom is a bombshell sweater girl blonde. 

Adam Smith had put economics on the map in 1776 with his analysis of how the ''invisible hand'' of competition would produce a natural allocation of resources in a market economy, as long as buyers and sellers were all free to do business at the market price. Barely 60 years then passed before the French educator Antoine Augustin Cournot showed how often markets were divided up between two or three big companies that might share the power to set prices and quantities, depending on one another's conduct. Cournot also put economics on the royal road to mathematics, arguing that it offered clarity that was possible no other way. 

Then came John von Neumann. The great Hungarian polymath - physicist, mathematician, computer inventor, Cold War theorist - arrived in Princeton from Europe with Albert Einstein in 1931. In 1944, he electrified economics with ''Theory of Games and Economic Behavior,'' which promised to give a rigorous new foundation to economics. To render his strategic approach mathematically tractable, however, Von Neumann had to make a couple of key assumptions. All situations would be ''zero-sum'' games - any win would be another's loss. And the range of possibilities would be known beforehand to players on both sides - games Nash later labelled ''cooperative.'' 

Nash took the analysis in a different direction, throwing out the zero-sum assumption and showing how individual decision-making was at the heart even of collusion. The effect was to reassemble the elements of game theory correctly, says Meyerson. ''The Nash program opened the door to information economics while the von Neumann program led away from it,'' he writes. It was far from obvious at the time. Von Neumann himself labelled Nash's insight ''trivial.'' 

Possessing a framework is not the same as knowing how to use it. It took many years before game theory came to rival traditional price theory as a framework for rigorous economic analysis. It will take many more years before we know which camp has won. Meanwhile, it is always fun to argue about what we mean by a great economist. Tool builders like Nash or Gerard Debreu? Operationalizers including Paul Samuelson and Milton Friedman? Modelers like Gary Becker and Robert Merton? Kenneth Arrow? Ronald Coase? Friedrich Hayek? What seems past arguing is the wisdom of giving the Nobel Economics Prize. How better to call public attention to a story as remarkable as that of John Nash?