TWO COURT DECISIONS last week have reestablished and strengthened the traditional boundaries between religion and the public schools. That's reason for celebration. For some months, a couple of eccentric decisions in the lower courts had seemed to put those boundaries in doubt. But last Monday the Sixth Circuit Court of Appeals said that exposing children to controversial ideas does not violate their rights, even though those ideas may offend their religious beliefs. Now the Eleventh Circuit Court of Appeals has reversed the Alabama textbook decision.

Last March a federal judge in Mobile ordered some 40 textbooks banned from the Alabama public school system on grounds that they promoted a religion -- secular humanism. It was an altogether bizarre ruling by a judge, W. Brevard Hand, who has made it clear that he does not consider himself bound by the Supreme Court in these affairs. Although the probability of reversal was very high, Judge Hand's logic was nevertheless disquieting, since, if the higher courts had entertained any part of it, the threat to public education would have been profound.

Reassuringly, the appeals court's decision sticks to common sense and the Constitution as heretofore understood. The appellate judges didn't bother asking whether secular humanism is a religion. Religion or not, they said, the Alabama school books don't promote it. Where the books touch religion, the court said, they convey information that is "essentially neutral." The plaintiffs, fundamentalist Christians, had argued that the state's history books slighted religion by neglecting its role in this country. The books may be inadequate in educational value, the court replied, but that's not a constitutional issue. The First Amendment, it said, requires schools to stay out of religion, not to give it equal time.

A series of recent cases in this area has raised anxious questions whether a new wave of anger and dissension over religious doctrine is rising in this country. There's little evidence of that. All of these three cases arise from a kind of dispute that is older than the Constitution itself; that's why its authors -- politicians and lawyers with much experience in these quarrels -- felt the need for the First Amendment. In many communities the majority has tried to impose its idea of truth on public usage, and the minority has protested. That's not new. It's one of the tensions inherent in a society that practices freedom of religion. It's always up to the courts to set the limits when religion and education get entangled, as they continually do. In this summer's cases the courts have maintained that essential wall in good repair, and in its familiar location