What the world owes Britannia

Many empires have left their mark - sometimes for better, often for worse - on history. Of modern empires, Britain's has been the largest, the most enduring , and probably the most conducive to the growth of a humane and rational global civilization.

Following Portugal and Spain, Britain expanded from the 16th through the early 20th century, when London dominated one-eighth of the world's population and land mass. Greed, ideals, and sheer momentum fed this expansion. Thus, from 1829 to 1833 Britain abolished the immolation of widows in India; claimed sovereignty in the Falklands; and ended slavery in all British possessions.

Within recent decades most peoples under British rule have obtained independence. Of these, most have opted to remain within the Commonwealth. Even in 1982, however, the sun never sets on British dependencies, which extend from Gibraltar to Diego Garcia, often overlapping with others' claims as in the case of the Falklands.

For Britain the balance sheet has been mixed. The slave trade helped finance the industrial revolution; overseas activities inspired and trained generations of public servants; but 1,000 pounds invested in English railways would have netted a higher return than the same investment in India. And the war with imperial Germany that grew from overseas competition virtually destroyed the cream of Britain's youth.

Whatever the costs and gains for Britain, the British empire has done much to make the world a better place.

Humanism and science have spread more easily because Britain gave the world a common language, one that even Chinese and Russians learn to join in the global exchange of ideas and goods. Caribbean poet Derek Walcott has agonized over the dilemma of a black man taking on the tongue of former slave masters. He and many third world leaders have decided that this language transcends national boundaries and purposes, and must be cultivated for its own beauty and one's own purposes.

Thus, African leaders such as Julius Nyerere translated Shakespeare into Swahili, even though Portia's rejection of blackness pained the African soul. Milton Obote chose his name for the author of ''Paradise Lost.''

Through this language the world also learns of ''fair play,'' ''gentleman's agreement,'' ''natural rights,'' ''no taxation without representation,'' ''trial by jury.'' Indeed, the whole apparatus of the British Parliament has been transferred throughout the Commonwealth. Though British political practices are sometimes abused, they remain for the most part an ideal by which behavior is measured in many third-world nations.

Britain's achievements are the more remarkable because the natural endowment of the British Isles is so limited. Their location gives some protection from European attack, but nothing like the vast oceans isolating the United States. Their iron and coal helped fuel industry, but Britain's mineral and food resources are meager compared to France or Germany, not to speak of the US. Other small nations also created huge empires - Portugal, Holland, Japan - but none so vast as Britain's.

Skill, tenacity, courage and intellectual brilliance played the greatest roles in creating and sustaining Britain's role in the world. All were put mightily to the test in 1940, after a decade of foolish appeasement. British mettle finally upset Hitler's schedule for the conquest of Eurasia. Recognizing Winston Churchill's contribution to civilization, many Germans joined other Europeans and Americans weeping at his funeral in 1965.

British foresight and pragmatism helped also in the devolution of imperial ties. Britain created educational systems, infrastructures, and a civil service tradition in its colonies superior to those created by other European powers.

British governors and armies withdrew without having to be defeated or stalemated like French or Portuguese armies in Indochina, Algeria, or Angola. Where they have long remained, as in Belize, the aim has been to ensure that a British protectorate is not swallowed by aggressive neighbors.

While the industrial revolution began in Britain, so did the current move toward ''small is beautiful.'' British investors helped develop the infrastructure of the US and Argentina as well as India. The shape of socialist as well as capitalist economies has been set by economists working in Britain - from Adam Smith and Karl Marx to Lord Keynes.

All mankind benefits from the work of perhaps the greatest scientist who ever lived, Sir Isaac Newton; the author of ''Origin of the Species, Charles Darwin; the explorations of Captain Cook; and philosophers such as Hume, Locke, and the Mills.

Beyond such giants of art and science; beyond such institutions as Greenwich Universal Time; beyond the Cambridge exams that measure academic excellence from Nigeria to Pakistan; beyond all this there is an intangible quality - a certain grace in discourse - that Great Britain has given the world.

This quality broadens our perspectives when Queen Elizabeth speaks French to Canadians celebrating their new Constitution; it bolsters our confidence in the possibility of concise and objective reporting when we hear a BBC news broadcast anywhere in the world.

This grace makes communication fruitful and meaningful in ways difficult to achieve in most cultures. One senses this quality in the frank give-and-take conversations of Australia or New Zealand after the deferential, status- and age-ridden communications prevailing in most of Asia. Even in Europe one notices the more open style of British participants in international meetings, uncluttered by concerns for grandeur, dolce vita, or wartime guilt burdening others.

The age of empire is behind us. The fact of interdependence and the question of what to do about it lie ahead. Britain has helped make the world interdependent - a point noted by Marx already in 1848. And it has given us many of the tools needed for coping with the dilemmas that interdependence entails.