WHEN I ACCEPTED a professorship at The George Washington University in 1980, several of my colleagues wondered: "Leaving Columbia University -- to move to Washington?" Washington was a notoriously un-academic and a-intellectual town, one of the few world capitals without a "major" university.

I am still asked that question, but much less often. Over the last few years, Washington crossed an admittedly ill-defined threshold beyond which cities qualify as major centers of research, higher learning and dissemination of knowledge. Just as it now has sidewalk cafes and more than 200 art galleries where there were 18 a decade ago, it now has so many new institutes and centers that, together with its older academic institutions, it easily matches the intellectual vigor of contemporary London. It also has almost as many little magazines (where intellectuals float new ideas) and writers- in-residence as the Left Bank of Paris.

A wit once said about a university that it consists of 37 departments that share nothing more than a heating system and a fight over parking privileges. By that criteria, this city has become the great Washington Metropolitan University -- a university without walls or a football team that is spread all over town. Vast amounts of research, higher learning and the conducting of seminars occurs at what might be considered its campuses: more than half a dozen universities in and around the Beltway, as well as at numerous other institutions ranging from the Center for Hellenistic Studies to the Institute for Educational Leadership and the Police Foundation.

To those, in recent years, a whole slew was added, including the Institute for International Economics, directed by C. Fred Bergsten, assistant secretary of the treasury for international affairs in the Carter administration (opened in 1981); the Roosevelt Center (1982) where Chicago commodities trader Richard Dennis is converting his millions into research-gold; the Center for National Policy (1981) created by Ted Van Dyke -- a former aide to Sen. Hubert H. Humphrey -- to serve up innovative Democratic thinking, and the libertarian CATO Institute (1977), which was founded by Edward H. Crane III, former national chairman of the Libertarian Party. These new centers add momentum to several older institutions that have been taking off in recent years. Take, for example, the Woodrow Wilson International Center for Scholars, whose 45 fellows are chosen in an annual international competition and who come to Washington to study a wide range of intellectual subjects with the center's small permanent staff in the Smithsonian Institution's main building. It opened its doors late in 1970, and in the last 10 years has evolved into a world-renowned humanities center, annually publishing half a dozen books ranging from American history, culture and society to studies of Russian literature and Latin America.

The Carnegie Endowment for International Peace sounds like a cross between a foundation and a do-good association. But actually, it issues a solid annual account of the state of nuclear proliferation in the world and a steady stream of scholarly articles.

Other "departments" of the Washington Metropolitan U. consist of older and more familiar places. A major campus is the National Institutes of Health, where more research in biology and related disciplines is conducted than at Harvard, Yale, Princeton, Columbia and Brown combined.

With an annual budget that exceeds half a billion dollars, more than 3,000 scientists work in labs, computer sheds and in government- issue cubbies. They match five major universities not merely in the size of their ranks; the stature of their work is internationally recognized. Research carried out at NIH yielded that ultimate seal of academic approval -- four Nobel Prizes.

Major research centers in economics and related subjects are tucked away within the World Bank, the Federal Reserve Board, and in the newer Congressional Budget Office (1975). Natural sciences are strong from the Carnegie Institute of Washington to the Smithsonian and the National Bureau of Standards, from scores of physicists working within the Defense Department to the Naval Research Laboratory. Academic life is not the same thing as intellectual life, but one begets the other. Many people confuse the two. Typical academicians are deep scholars of narrow matters. There are no historians, but scholars of the Civil War, or naval history, or the Crusaders, and so on. Intellectuals, on the other hand, are masters of the broad brush; they provide perspectives on the direction of history, the changing American society, trends in literature and such. And recently, intellectuals stopped jumping on the shuttle to return to New York or Cambridge as the sun sets. Many now live in D.C. because they find the academic abundance highly congenial.

Intellectuals feed on academic work; they get the evidence they interpret, synthesize and generalize from rubbing shoulders with academians. And eggheads find in universities and major think tanks, the tenure that shelters their ability to write freely, and the secure income that allows them to lead a life of reflection and commentary.

Michael Novak, a conservative social philosopher who recently took on the Catholic Church in the name of capitalism, is comfortable at the American Enterprise Institute. Norman Birnbaum, a radical sociologist, and conservative historian Walter Laqueur are nestled at Georgetown, although Laqueur divides his time among London, Jerusalem and Washington. Many others, as they do in all university towns, live at the margins of the campuses and institutes.

Although both academians and intellectuals are distainful of the masses, they love (and need) to talk with one another and reach out to appropriately appreciative audiences. Beyond endless seminars, little magazines are their favorite way to keep the pots fired up. Over the last years Washington Metropolitan U. has launched a surprising number of these, many quite outstanding.

These include, to name a few, "The Wilson Quarterly" the Wilson Center's humanistic publication; AEI'S influential "Public Opinion," a zippy current report of American attitudes, and "Regulation," which publishes studies of the dynamics and effects of government interventions. The iconoclastic "Cato Journal," prints libertarian rhetoric and studies. The up-and-coming "Foreign Policy," regularly challenges the stodgy "Foreign Affairs" published in New York.

"Science," easily the best natural sciences publication in the country, recently spawned an offspring, the popular "Science '85." And the National Academy of Sciences is publishing the new "Issues in Science and Technology." Moreover, the rising academic/intellectual core contributes to Washington's greatly improved newspaper and to its acclaimed TV news programs, the "MacNeil-Lehrer Newshour" and "Nightline."

What is missing most is recognition. Some Washingtonians still believe that in the U.S.A., a center of politics and of academe cannot co- exist in the same town. Somehow they feel that if a Harvard University Henry Kissinger or a Columbia University Zbigniew Brzezinski do their work in D.C., they must have come down in the academic pecking order. In effect the opposite has happened: Washington is moving up. A large part of this change is that the traditional universities of the area are undergoing their own boom, and I do not mean simply in real estate. The test scores of applying students are rising. Recently Edward B. Fiske's much-followed "Selective Guide to Colleges" awarded Georgetown University a four-star rating (out of a possible five). The George Washington University created in 1980 a professorial super- rank that has been used well to draw to Washington academics who established themselves elsewhere. These now include a leading scholar of Islam, a distinguished social philosopher, a renowned historian and a sociologist.

George Mason University was barely on the academic map 10 years ago. It started to award PhDs only in 1980. Now it is a beehive of 26 research institutes, many in high tech. It is also the center of a major new social-science school, "Public Choice," that studies in a peculiar manner the complex relations between the economy and political processes. In effect, it asks, "Does what politicians do make sense to an economist?"

Although it would not be fair to include Johns Hopkins as a Washington institution even for those who see Baltimore as nothing but a D.C. suburb, SAIS, Johns Hopkins' distinguished School of Advanced International Studies, is right in the center of Washington.

Howard University is growing great guns. Its scientists opened a major institute to study the design of large space structures (space colonies in the popular vernacular); it is doing numerous kidney transplants and developing a capacity also to do liver transplants; and it opened an internationally recognized laser and fiber optics laboratory.

For those who study universities, next to the caliber of scholars, the cardinal question is the quality of the library. While the libraries of the Washington universities have a way to go before they match the collections amassed by Ivy League colleges, the best library in the country is of course the Library of Congress. And, enough documents to keep a legion of scholars busy are at the National Archives. Washingtonians chatter with glee about the transformation of this small Southern hick town into a genuine national metropolitan center. And when the conversations turn from subways that no longer shut down at dusk to intellectual matters, the names of the big liberal and conservative think tanks often pop up -- Brookings, the American Enterprise Institute, the Urban Institute, and the Heritage Foundation.

Actually they provide both less and more than meets the eye. To the extent that think tanks conduct so-called "policy studies" that serve the government -- from how to reduce the use of energy to how to impose flat taxes, -- these institutes are engaged in what academians contemptuously called "applied research." Real academicians aspire to advance scholarship, science for its own sake ("basic research").

True, these endeavors may eventually enrich the body of knowledge on which applied research draws. Also, academicians, when faced with ax-wielding budget cutters, will stoop to point to such uses of their work to defend their allotments. But, within the privacy of the faculty clubs and departmental meetings, the message is quite clear: Real academicians neither wash windows nor do policy research. They study medieval Europe, Japanese character formation, and the scope of the universe.

The hidden beauty of the think tanks, through academic eyes, is that a fair proportion of their work really is academic. Government agencies, corporations and foundations may contract with these centers to produce policy research, but because many of the staffers are ex- professors, aspiring professors, or professors who double as staffers, they turn out splendid academic tomes, to the greater glory of the Washington Metropolitan U. For instance, Norman Ornstein of the American Enterprise Institute (and Catholic University) studies interest groups. And his research is not more applied or less scholarly than such research conducted, say, at Berkeley.

And the scientists at NIH have been objecting for decades to pressures from Congress and the public to focus on diseases -- especially cancer -- and would rather study the structure of the cell and genetic switches both because these subjects are "basic research" and because the scientists believe that in the longer run, such study is the best way to combat disease. And even in the smaller pockets of research most government agencies keep deep in their corridors' ends, one finds such academic proclivites.

Some years back I was asked to conduct an intra-agency review of the U.S. Commissioner of Education. I found that he had a very small staff working directly for him, and had a hard time getting the information he required to evolve policies he was interested in. In the same agency and building, 119 researchers were busy studying numerous aspects of education and issuing reports reqularly. I visited them to discuss their becoming more responsive to the commissioner, and to their agency (and the country's) policy needs.

"Not on your life" was the unanimous response. Their pride, joy, and ambition was academic work. Indeed, their allies on the campus called me and warned that if the comissioner turned the research to "applied," they would appeal to their friends in Congress to gut the agency's research budget.

All over Washington, openly and secretly, government hired PhD's from the CIA to the Census Bureau, to NIMH, on the side and while at work, research is conducted and written up in reports that are indistinguishable from those prepared at the heights of the academic ivory towers from Stanford's Hoover Institute to MIT's Technology Square. It may be distressing to their department heads and to OMB, but it adds grist to the academic mills of W.M.C. True, government hands have been grinding academic stuff on the sly and in broad daylight for many years. What is new is the quantum jump in their numbers. Academians need intercourse; they thrive on the exchange of notes and footnotes, arcane sources and the latest in measurements. For the academic buzz to rise requires a critical mass, the coming into town of a sufficient quantity and caliber of academians.

And these ranks are further strengthened by a steady flow of scientists and engineers atracted to Washington by the growing defense and high-tech industries, and -- by one another. As a result, from September to May (the academic year) when you open a door in every tall building between Gaithersburg and Tysons Corner and see a meeting, odds are it is not a conference of bureaucrats but a seminar on some highly esoteric scientific, technical or academic matter. And increasingly they branch into inter-disciplinary subjects from socio-economics to bio-chemistry and bring together individuals from many of Washington Metropolitan University's departments sprawled over the Washington area.

Universities in a nation's capital ought to be more than "major"; they serve best if their professors mingle with legislators and heads of agencies. At issue is not testifying before congressional committees or serving as a consultant, which academicians from out of town can do. What matters is frequent informal exchanges in which new ideas are communicated to the government, and new concerns of the government explained to the research community. These exchanges occur increasingly during Washington's famous cocktail parties and private dinners. One day it will make Washington not merely a great university town, but might also make its policy makers wiser.