Where does sedition lurk these days in the minds of Americans? Justice Harry Blackmun knows: behind every effort to restrain the practice of abortion, he sees the willful refusal to concede that when the Supreme court has spoken, the final, authoritative word has been said on the meaning of the Constitution. And so Blackmun loosed his terrible swift sword on the solicitor general very recently, during an argument before the court over the laws on abortion.

The justice asked Rex Lee whether the administration was requesting the court, in effect, to overrule Roe v. Wade, the decision that made abortions legal for virtually any reason, at any stage of the pregnancy. When Lee denied that the administration was seeking that change just yet, Blackmun replied with sarcasm that "it seems to me . . . you are asking that or you're asking that we overrule Marbury v. Madison."

It is apparently a long while since Justice Blackmun has studied Marbury v. Madison, or he has absorbed now the fable that has been fashioned mainly by judges: that the case that established the authority of the court to interpret the Constitution also established the court as the sole, authoritative interpreter of the Constitution. In this superstition he is joined by most judges.

And yet, that understanding was not shared by the Founders, and it found no expression in the Constitution they framed. Nor was that understanding ever set forth by Chief Justice Marshall in his classic opinion in Marbury v. Madison. In later years, the supporters of the Dred Scott decision claimed that the court must be sovereign in settling the meaning of the Constitution. But that argument was rejected officially, decisively, by the Lincoln administration with reasoning -- and precedent -- that we could not wish to overturn, even today.

In Marbury v. Madison, Marshall had to confront a case in which a statute passed by Congress came into conflict with an explicit provision of the Constitution. If the court failed to give precedence to the Constitution, then it would implicitly lower the Constitution to the plane of an ordinary statute, which could be altered and superseded by any piece of subsequent legislation. But if the Constitution had to be regarded as "fundamental law," then it had to follow, as Marshall said, that "those who apply the rule to particular cases, must of necessity expound and interpret that rule. If two laws conflict with each other, the courts must decide on the operation of each."

This "judicial duty," as Marshall described it, was modestly drawn: Marshall simply recognized that the court had an obligation to be governed by the Constitution as it sought to settle the particular case that was submitted for its judgment. In that sense, nothing was claimed for the judges that could not be claimed for other officers of the government: presidents and congressmen would also be obliged to consider whether their decisions were compatible with the text or the principles of the Constitution.

Such, at any rate, was the understanding of Thomas Jefferson and Andrew Jackson, and, without that traditional understanding, it would be hard to grasp Lincoln's resistance to the Dred Scott decision. In that infamous case, the court "established" that blacks could not have the standing of citizens to sue in the courts, and that no man could be deprived of his property in slaves, even if he brought that property into the territories in which slavery had been forbidden by Congress.

In respecting the processes of law, Lincoln was willing to respect the disposition made by the court in settling the fate of Dred Scott in this case. But he and his party would "oppose that decision as a political rule which shall be binding on the . . . members of Congress or the President to favor no measure that does not actually concur with the principles of that decision."

Lincoln was willing, that is, to accept the judgment of the case as it bore on the conflict between two litigants. What he was not obliged to accept was the principle or the broader rule of law that the court was trying to create in the case. As Alexander Hamilton once remarked, the court had neither the power of the sword nor of the purse; its authority would ultimately depend on the force of its reasoned argument. In that spirit, Lincoln insisted that other officers of the government could not be obliged to accept any new "law" created by the court unless they, too, were persuaded by the force of the court's reasoning.

The Lincoln administration came to discover very quickly just how far the executive branch had been willing to apply the principle of the Dred Scott decision. In two notable cases arising from Boston, a black student had been denied a passport to study in France and a black inventor had been denied a patent on a new invention. Since the court had decided, in Dred Scott, that blacks were not citizens, the local agents of the federal government now reasoned that blacks could not carry the passports of American citizens and they could not receive patents under the laws of United States.

The Lincoln administration reversed both decisions. The attorney general announced that the administration would be guided by its own understanding: that free blacks born in the United States were citizens of the United States. A year later Lincoln would sign new legislation that banned slavery from the territories of the United States--as the president affirmed, again, that in the decisions which came under his hand he would not be bound by the "principles" declared by the court in the Dred Scott case.

And yet, in the understanding that now dominates the federal courts, these moves of the Lincoln administration would be regarded as unconstitutional. They would be defensible only on the understanding held by Lincoln and the Founders about the separation of powers and the responsibility of each branch to interpret the Constitution. But when Congress and the state legislatures seek, in our own day, to restrict the practice of abortion, their efforts are instantly branded as unconstitutional if they seem to be acting on the premise that abortion is wrong. Since the Supreme Court "established," in Roe v. Wade, that abortion is a legitimate medical procedure, it is assumed now that it is impermissible for Congress or the states to legislate upon any other premise. To do that would be treason to Roe v. Wade, and in the temper of Justice Blackmun, treason to Roe v. Wade is treason to the Constitution itself.

But if Blackmun persistently faces, on the matter of abortion, an opposition that will not be stilled, it is precisely because the court has not passed the test proposed by Hamilton: 10 years after Roe v. Wade, people of serious reflection have simply not found compelling or persuasive the reasons offered by the court. A majority of women remain convinced that life begins at conception, that the offspring of Homo sapiens cannot be anything other than human from its very beginning, and that the matter cannot be, as Blackmun suggested, an inscrutable religious question.

In the spirit of Lincoln, legislators in Congress and the states are claiming their right to honor their own judgments in the matters that come before them; and in the spirit of the separation of powers -- the spirit of shared powers and reasoned exchange -- they would urge the court to take a sober second look at what it has done and consider the possibility that it might have been mistaken.