Any Supreme Court decision regarding ''creationism,'' however wise or correct, is sure to leave loose strings dangling. The court's June 19 decision invalidating Louisiana's creation-science statute, though both wise and correct, did just that.

At the core of this long-lingering controversy lie questions that elude judicial wisdom. And perhaps the most important of them has to do with the nature and scope of educational authority: who has it and who doesn't. Is there really a clash between religion and science, or a difference between science and pseudoscience? If there is, who may authoritatively pronounce on such questions?

Not Supreme Court justices, however wise. They can only say, as seven did the other day, that Louisiana may not require public-school instruction in ''creation science'' as a counterbalance to instruction in evolutionary biology. Such a law, they ruled, promotes religion and infringes the First Amendment. Though inspired by pressures from religious fundamentalists, the law was officially justified as promoting ''academic freedom.'' But it is a strange brand of academic freedom -- a term ordinarily associated with the freedom to teach -- that narrows the discretion of qualified classroom teachers.

More confusion flows from the attempt to confer identical academic standing on both a science and a pseudoscience.

In modern biology, authority lies, as it has for a century or more, with the theory of evolution by natural selection. That this powerful theory has undergone continuing change and refinement should not be taken, as it often is by promoters of creationist alternatives, as evidence that it is weak or shaky. It is not.

Not that very many creationists seem to be motivated by a conviction that creationism is good science. Rather they believe that it promotes sound human values. They believe children should be instructed that the human species was created in its complex form by a personal God. They have the unfortunate misimpression that modern science -- especially evolutionary biology -- contradicts their faith and promotes a law-of-the-jungle morality.

In fact, the real foe haunting the imaginations of creationists is not science but scientism, a very different thing. Scientism is a philosophical view, as speculative as any other, that identifies all causation in the universe as materialistic.

But good science -- including good biology -- makes no metaphysical speculations. True, natural selection, the heart of the Darwinian theory of evolution, does appear materialist. In fact, however, it makes no speculative assertions about ultimate causes and purposes. It merely undertakes to describe and explain a process, supported by overwhelming evidence, by which life forms originate and develop.

In a public-school course in speculative or religious philosophies, ''creationism'' might be an appropriate subject of study -- and a perfectly constitutional one. It is only when it is misidentified as a ''science'' and its teaching mandated to offset the supposed evils of evolution that it violates both the First Amendment and sound principles of learning.

The culprit here, almost certainly, is egalitarianism, which has overflowed its natural boundaries. In appropriate settings, the theory of political equality can be both useful and valid -- as for instance when it promotes equal protection of the laws.

When bootlegged into inappropriate settings (and design of school curricula is one), egalitarianism merely causes pointless strife and confusion.

No majority sentiment, however overwhelming, can confer legitimacy on a bogus body of learning; nor can the term ''science,'' affixed as a talismanic label, confer scientific status on a pseudoscience. A Gallup Poll might, for instance, discover a 95 percent belief in astrology. But that would not make astrology a peer of astronomy among serious scholars.

In other, more practical settings, this hierarchical principle is understood and respected. We do not turn to uninstructed majority sentiment to tell pilots how to fly 747s, or surgeons how to perform brain surgery. But out of a distorted notion of equality and ''fair play,'' we now habitually defer to unfounded challenges to qualified educational authority. The Louisiana ''creation science'' law is a showcase example.

It would be wonderfully helpful if the Supreme Court could reinforce beleaguered scholarly authority. Its task is more modest. The justices may say, wisely and correctly, that the Louisiana law promotes religion and violates the Establishment Clause. The judgment is useful, even essential. But it carries us only to the outer fringes of a fascinating controversy that shows no sign of vanishing.