IN THE ORDINARY course of things, there isn't much reason to pay attention to a court decision that affects the schools of just one state, but a recent decision of the Fifth Circuit Court of Appeals involving the state of Texas is an exception. The issue involved is an important one: how to educate children whose native language is Spanish. It is particularly important in Texas, where 22 percent of the nation's 3 million Spanish-speaking school- age children live. And its importance has been increased by the Supreme Court decision last month, which overturned a Texas law and required that state henceforth to educate children of illegal aliens, the large majority of whom in Texas are Spanish- speaking.

Finally, the decision is important because it is so sensible. The appeals court here was faced with an order issued by a single district judge requiring that every public school in the state of Texas provide Spanish-speaking pupils with instruction in Spanish in every grade. The order was entered even though the Texas legislature--admittedly, acting under pressure because of the court's ruling--passed a law requiring special instruction for Spanish-speaking pupils, but giving schools a choice between a number of programs. The appeals court overturned the trial court's ruling, making the common-sense point that "the issue is essentially a pedagogic one: how best to teach comprehension of a language. Neither we nor the trial court possess special competence in such matters."

This is not to say that nobody does. On the contrary, school districts all over the country, faced with increasing numbers of non-English-speaking students, have experimented with a variety of approaches and have found many that work. They have also found that different students, coming from a variety of backgrounds and entering school at different ages, need different approaches. The Reagan administration this spring wisely abandoned the attempt to tell local school districts they have to provide instruction in the child's first language. Now the courts in the important state of Texas have done the same thing. "There is no legal or research basis," one expert writes in the Harvard Educational Review, "for the federal government to advocate or require a specific educational approach."

These rulings do not mean that our schools do not have an affirmative obligation to provide special help to pupils speaking a foreign language. They do. But they should not be forced to rely on a single, rigid approach by either the Department of Education or the courts. And they should not lose sight of the goal--a goal whose worth and feasibility has been demonstrated again and again by the past century of our history. That goal is to teach children to speak and write English. We should give educators the leeway to abandon bilingual education programs that mistakenly keep children learning primarily in their native language and deny them the opportunity to master the language in which business and public affairs in this country are conducted.