CHIEF JUSTICE Warren E. Burger is not known as a judicial activist and the Burger Court is not conventionally thought to be an activist court. But the methodology of Burger's opinion Tuesday for an 8-to-1 court in the Bob Jones Univercase, combined with the rationale of several other recent decisions, gives the federal judiciary a creative license with unlimited possibilities for the exercise of judicial power.

In the Bob Jones case, the court ruled that the Internal Revenue Service may deny tax-exempt status to racially discriminatory private schools even though Congress never authorized the practice. Burger said the IRS had been carrying out the policy since 1970. Congress knew about it and raised no objections, he said. It acquiesed.

That, he said, is tantamount to approval. Apparently the court believes Congress approves of anything it doesn't disapprove of.

A large proportion of the controversies in the federal judiciary are, like Bob Jones, questions of congressional intent. They are in the courts because Congress ducks important questions in many statutes and leaves out crucial details, sometimes because it cannot -- or doesn't want to -- agree on them. Under the rationale of Bob Jones, Congress' failure to act becomes the act itself. If Congress doesn't say "no," the answer is "yes."

Liberals who approve of the Bob Jones opinion should look at one of the prior cases cited by Burger in support of the Jones ruling to understand that it's a two-edged sword. That 1981 case, Haig v. Agee, upheld the revocation of the passport of former CIA agent Philip Agee for traveling around the world exposing purported CIA agents. It gave the government discretion to deny travel abroad to citizens it believes threaten the national security or U.S. foreign policy.

Burger acknowleged there, as he did in Bob Jones, that Congress had not "in so many words" empowered the secretary of state to do what he did. But, he said, Congress didn't specifically act to deny him that authority. So it must be all right.

In fairness to Burger, it was crucial to the Bob Jones ruling that various congressional committees over the years had rejected a number of bills to stop the IRS from denying the tax exemptions. "Non-action by Congress is not often a useful guide," he said, "but the non-action here is significant."

Justice Lewis F. Powell Jr. was clearly uncomfortable with the approach, though he could not bring himself to vote with a racist college. In the future, Powell said in a statement concurring with Burger's opinion, "these questions should be legislative policy choices. . . . The contours of public policy should be determined by Congress, not by judges or the IRS."

Justice William H. Rehnquist, usually a Burger ally, was the lone dissenter. Considering the fact that Congress knows how to amend the tax law when it wants to, Rehnquist wrote, "this Court has no business finding that Congress has adopted the new IRS position by failing to enact legislation to reverse it."

If your ox wasn't gored on Bob Jones or Haig v. Agee, try Merrill Lynch v. Curran last May, another precedent cited by Burger in the Bob Jones case. The question there was whether purchasers and sellers of futures contracts could sue futures traders and brokers for fraud under the Commodity Exchange Act. It was an important question Congress had never answered.

This time it was Justice John Paul Stevens acknowledging the congressional silence. But he said in a 5-to-4 decision that lower federal courts had "routinely and consistently" recognized the private right to sue under the commodities law. Congress, on the many occasions it revised the law, was aware of those court rulings and did nothing to overrule them, he said. Therefore, Congress approved.

Stevens opinion drew a lengthy dissent written by Powell. The decision, the dissenters said, "is disquieting because of its implicit view of the judicial role in the creation of federal law. The Court propounds a test that taxes the legislative branch with a duty to respond to opinions of the lower federal courts. The penalty for silence is the risk of having those erroneous judicial opinions imputed to Congress itself. . . . This view is inconsistent with the theory and structure of our constitutional government," Powell wrote. Burger was among those joining him.