Former senator J. William Fulbright, his Oxford tutor once said, is responsible for the largest and most significant movement of scholars across the face of the earth since the fall of Constantinople in 1453.

Forty years ago next month, China agreed to accept the first American Fulbright scholar, Derk Bodde, a Sinologist from the University of Pennsylvania.

Now, Fulbright scholars are helping to rule the world.

This week, a few hundred Fulbright alumni will meet in Washington. They'll consider the state of the world and the scholars thereto, and think of ways to promote peace through understanding. They're only a small group of the 60,000 American Fulbright scholars who've studied abroad and the 100,000 foreign scholars who've come to the United States under the program, but after 10 years as a rather small group, they're getting themselves organized. Harriet Mayor, head of the alumni office, said that 23 embassies are briefing and receiving the alumni. And both a concert and an art exhibit will be part of the reunion.

The alumni association has begun by moving its offices to Washington, to be closer to the Congress, from whom the blessings flow, and to the font of knowledge himself. The program now is under the U.S. Information Agency, but Fulbright thinks it should be a Smithsonian program, so as to seem less a propaganda effort and more an academic one.

Fulbright himself at 82 is literally a dictionary synonym for scholarship, a practicing lawyer and a mighty beater of swords into plowshares. He keeps busy pontificating, lobbying for the program and appearing as an august presence at Washington gatherings of an international flavor. He is fond of pronouncing, between the shrimp and the salmon at parties, that "the 160,000 scholars in the 40 or so years of the program have cost the United States less than a third of a nuclear submarine."

In 1977 he used to say that the Fulbright program cost "maybe half as much as a Trident submarine," but inflation has overtaken his caution.

The scholar program began as a way to use monies owed the United States by countries defeated in World War II. Now 29 countries contribute to it. In all, says Fulbright, still beating, "the scholarships have cost less than $1 billion, yet last week the Congress authorized $302 billion for military expenditures."

Fulbright enjoys hoisting names of the world leaders who studied under the aegis of Fulbright. Sen. Pat Moynihan (D-N.Y.) and Rep. Donald J. Pease (D-Ore.) are two of them. Former astronaut and senator Harrison H. Schmitt is another.

Alexander Yakovlev, Soviet leader Mikhail Gorbachev's key adviser, went to Columbia University. Margaret Thatcher was on a visiting program. Former Japanese ambassador to the United States Yoshio Okawara, who accompanied the crown prince on his visit here last week, also studied here. Swedish Prime Minister Ingvar Carlsson did postgraduate work at Northwestern. In some countries, a Fulbright has become almost a qualification to be named to the cabinet, the supreme court or an ambassadorship.

Last year, the Board of Foreign Scholarships counted in Japan alone seven Fulbrighters as members of the Diet, 34 as active ambassadors, one as a former chief justice and three as current justices, 27 as presidents of universities and 100 as senior executives, as well as multitudinous newspaper writers and television commentators.

Fulbright, former chairman of the Senate Foreign Relations Committee and a mighty opponent of the Vietnam war, still is counted as one of Washington's great oracles:

"In the long run, we have to change the attitude of people to people. There's no way to build defense. We can already destroy each other with weapons. In the old warfare, the land could get over it. Now it poisons the whole country. Einstein said after the bomb, 'Now everything has changed except our manner of thinking. If we don't change, mankind will suffer an incalculable catastrophe.'

"And he didn't mean changing how you like potatoes. Living and studying in other people's countries helps get over the human tendency to go to war every little bit."

Fulbright should know -- he went from Arkansas to Oxford as a Rhodes scholar, and he came back to change the course of history.