CONSERVATISM IS A DEFENSE of tradition. Yet Attorney General Edwin Meese III defends tradition by attacking at least 60 years of Supreme Court precedent. His version of conservatism, elaborated in a July speech to the American Bar Association, is so unprecedented, such a radical departure from settled law, that he has provoked two Supreme Court justices -- John Paul Stevens and William Brennan -- to descend from the high bench and upbraid him for his extreme misreading of American history and law.

This extraordinary spectacle is neither politics nor law as usual. It is not the latest Washington sporting event. It is not about who's up, down, in or out. It is not a contest between personalities or even institutions. Rather, this is a conflict over bedrock philosophy, the meaning of the American past as it applies to current law.

Although the legal back-and-forth may sound abstract, it is as politically immediate as the conservative movement's ideological agenda, imposed by a newly enthroned federal judiciary, more than half of which will be selected by President Reagan and Meese.

On a whole host of issues -- affirmative action, abortion and school prayer, among others -- the conservatives seek to rescind the standing law. But they want far more than alterations in mere policy; they want a fundamental transformation of the philosophy underlying these policies, so that such reforms are impossible in the future. Thus, the movement conservatives are acting to discredit established canons of judicial interpretation.

Meese may be an unlikely philosopher, but his statement was no spontaneous prank. The concepts he espouses -- including the notion that the Bill of Rights should not be applied to the states -- have a lineage that runs deep in conservative-movement history, particularly the post-1945 writings that have shaped the "Reagan revolution." These ideas, moreover, are aggressively promoted by the foundations and think tanks of the Washington conservative establishment especially devoted to law.

For months, in various interviews, Meese has been suggesting that his view of the law is undergirded by philosophical principle -- that it is more than an ideological instinct.

We must, he said, go "back to basic principles." The Supreme Court ruling legalizing abortion, Roe v. Wade, is not really "an abortion case." It is, he declared, about "the more fundamental principle that's involved there . . . the separation of powers." The court's ruling, he added, is "an arrogation of power away from the states." Then he labeled the Miranda decision, requiring that criminal suspects be informed of their rights, "infamous." "You don't have many criminal suspects who are innocent of a crime," he said.

In his ABA speech, Meese attempted to explain his various complaints as deductions from a coherent doctrine. At each step of his logic he journeyed farther into the past. First, he assailed the extension of the guarantees in the Bill of Rights to the states, a process that began with a Supreme Court ruling in 1925 stating that the First Amendment applied to state action. This was, Meese claimed, "politically violent and constitutionally suspect."

In place of decades of court precedent -- supposedly warping federalism and criminal law -- Meese offered something he called a "Jurisprudence of Original Intention" -- a jurisprudence based on a "correct" reading of the Founding Fathers' collective mind.

"We will," he said, "endeavor to resurrect the original meaning of constitutional provisions and statutes as the only reliable guide for judgment." As an example, he noted that "neutrality between religion and irreligion would have struck the founding generation as bizarre."

With "original intention" enshrined as the reigning philosophy, vast areas of the law would have to be rewritten. Yet, as Meese and the movement conservatives see it, the courts are already thoroughly politicized. To them, the pre-Reagan federal judges act as a priesthood of "judicial activists" who, by attempting to reconcile precedent with changing reality, are promulgating a liberal ideology. In their effort to return to "original intention," the conservatives are attempting to cleanse the legal system of this liberal tincture. This places them, they believe, in the position of defending tradition against the ideological cadre dressed in black robes.

Meese soon provoked a thunderous response. Justice Brennan issued his judgment that the doctrine of "original intention" is "arrogance cloaked as humility." More, it is a cry "from persons who have no familiarity with the historical record." He dismissed "this facile historicism," which seeks to justify itself as "a depoliticization of the judiciary." To Brennan, the hypocritical "political underpinnings of such a choice should not escape notice."

Having dispatched "original intention," Brennan proceeded to train his sights on Meese's Bill of Rights heresy. More than 60 years of law is at stake, he observed; for the 1925 ruling that the Bill of Rights preempts state rights was made possible by the Civil War amendments to the constitution. "It was in particular," he said, "the Fourteenth Amendment's guarantee that no person be deprived of life, liberty or property without process of law that led us to apply many of the specific guarantees of the Bill of Rights to the states."

On this point stand Supreme Court decisions for decades, including such cases as Near v. Minnesota (1931) which held that freedom of the press could not be abridged by a state, Gideon v. Wainwright (1963) guaranteeing counsel to all poor defendants, to New York Times v. Sullivan (1964), which held libel suits must be considered in the light of freedom of speech.

Justice Stevens pursued these questions even more directly than Brennan. He cited Meese by name, and then dealt with his propositions about the Bill of Rights and "original intention" as one. To accept the Meese position, he pointed out, "overlooks the profound importance of the Civil War and the post-war amendments on the structure of our government . . . ." Almost as an aside, Stevens derided Meese's implicit view that the "founding generation" thought as a monolith.

Why, suddenly, this heated debate about the "founding generation" and the Civil War? What does "original intention" have to do with Meese's intention?

The roots of the controversy spread into the past, an obscure but real past thus far unremarked upon by Meese, but the source of most of his ideas. The thread of this heritage runs from the Founing Fathers to Jefferson Davis and the Confederacy, from the nostalgic 20th- century Southern Agrarians such as Richard Weaver, to the early "movement" intellectuals like Willmoore Kendall, and at last to the ideological bastions of contemporary Washington.

"Original intention" as a constitutional strategy can in fact be traced to the late l8th century. But, as W. Jefferson Powell details in the March issue of the Harvard Law Review, "original intent" back then did not refer to the Founding Fathers at all, as Meese has insisted. Instead, "intention" referred to "the parties to the constitutional compact -- the states as political entities." Meese's idea that "intention" meant the framers is, according to Powell, "historically mistaken."

As the Civil War drew near, the states' rights advocates who had spoken of "original intent" began to lace their rhetoric with references to the framers. This view was most succinctly expressed by Jefferson Davis in his inaugural address as president of the Confederacy. The Confederacy's constitution, he asserted, is "the Constitution formed by our fathers," differing only "insofar as it is explanatory of their well-known intent."

The banner of the South's lost cause was hoisted in the 20th century by the Southern Agrarians who, while not rationalizing slavery, cast a romantic haze over ante- bellum society. One of them, Richard Weaver, an English professor at the University of Chicago, argued that the South had not really been defeated, but remained a land of superior values against the liberal modernity of the North.

In 1948, his book, "Ideas Have Consequences," was published, a outcry against "modern barbarity." The book is widely considered by conservatives to be one of the starting points of their movement; its title has become a conservative cliche and Weaver is upheld as an icon.

Weaver's thought did not touch on the legal realm, but he strongly influenced another intellectual founder of movement conservatism -- Willmoore Kendall, the Yale political scientist who influenced, among other students, William F. Buckley Jr.

Kendall taught that modern liberals were the "legitimate offspring" of Lincoln, where the problem really started. This "strong" president injected a "cancer" into the American system that threatened its "very survival." And this "cancer" was the clauses of the Fourteenth Amendment guaranteeing the right of "due process" and "equal protection" under the law. Kendall, however, was not an "original intention" advocate. Instead, he urged conservatives to "get busy and amend the Fourteenth Amendment," from which flowed many of the innovations of the Warren Court.

The law that was made after the North won the Civil War reflected a new political alignment. The attempt now to undo this law reflects a renewed opposition to the metropolitan values of the North as promoted by the federal government.

Movement conservatism is built upon the ruins of Lincoln Republicanism. Inside the GOP, at the height of the civil-rights controversy, the conservatives gained control of the 1964 convention by relying on a broad Southern strategy. This has since become the base of their general election strategy. But after the waning of the civil- rights crisis -- the proximate cause of the electoral shift in the South -- the conservatives have seized upon other divisive social issues in the effort to effect a more sweeping and lasting realignment.

The condition of the conservative ascendancy is the fall of the Republicanism whose philosophical identity has been premised on the Civil War amendments the party's founders sponsored. The ultimate expression of this stream of thought was the law laid down by Chief Justice Earl Warren, whom the conservatives consider the fount of much evil.

To remove the most stubborn impediment to the conservatives' political ambitions, they are now challenging the constitutional legitimacy of modern jurisprudence. This is more than intra-party factional warfare. In order to achieve their aims, the conservatives must overthrow more than a partisan position. They must overthrow the larger legacy of Lincoln, a legacy of civil rights and strong national government, which has long become part of the country's bone and fiber.

The effort to enact an ideology has naturally produced an ideological confrontation. But the vehemence of the attack by Justices Brennan and Stevens on Meese's position has startled many on his staff, according to a source close to him. In the attorney general's future speeches, this source says, he may present a rhetoric without so many jagged edges. Yet this would merely be a tactical retreat, signifying no change in his commitment.

Reagan has succeeded in cloaking conservatism with his geniality. And yet even he has occasionally slipped. In his first inaugural, he said: "The states created the federal government," flatly contradicting Lincoln, who said: "The Union is older than any of the states and, in fact, it created them as states." In the movement conservatives' siege of the judicial citadel, Meese has unfurled an unadorned ideology, exposing it to an examination from which Reagan has mostly protected it.

The attorney general's enterprise is partly made possible by a recently emerged conservative legal establishment located around Washington. Benchmark magazine, for instance, which deals with legal issues, is published by the Center for Judicial Studies, a think tank directed by James McClellan, a former aide to New Right Senator Jesse Helms (R.-N.C.). The Benchmark book review editor is Gary McDowell, a Justice Department public affairs aide, who has castigated the Supreme Court for making the states adhere to the constitutional stipulations on religion, speech and other rights. Senior editor Grover Rees is in charge of judicial selection at the Justice Department.

Another senior editor, William Kristol (son of neoconservative "godfather" Irving Kristol), denouncer of the "judicial activists," is the special assistant to Secretary of Education William Bennett. And contributor Daniel Popeo is the head of the Washington Legal Foundation, which files briefs for New Right causes.

Benchmark's Supreme Court editor, Bruce Fein, the former general counsel to the Federal Communcations Commission, is associated with a host of conservative think tanks, including the American Enterprise Institute and the Heritage Foundation.

Fein has been perhaps the most direct influence on Meese's formulations. Fein's speech on last year's Supreme Court term -- delivered at AEI -- was well-attended by note-taking Justice Department aides. Unsurprisingly, Meese's ABA speech follows Fein's speech concept by concept and, often, phrase by phrase.

While these theorists seek to deny "judicial activists" interpretative latitude, their own legal doctrine also depends on an interpretation of American history. The concept of "original intention," however, implies there are eternal precepts immune to any modernization. For some inexplicable reason, the Constitution of 1787 stands outside history, but the Civil War amendments do not -- a selective reverence for the past.

Apparently, what is older is better. In their analysis, the conservatives portray the Founding Fathers as super-human seers -- the only ones permitted to shape the present. But since the founders are not here, the conservatives must act as their proxies. It seems that the founders' ability to peer into the future is matched by the conservatives' ability to conjure the "original intention" lodged in the past.

What this ideology lacks in intellectual coherence it compensates for with political coherence provided by the conservative movement, which half-camouflages its desire for judicial power with strafing of the judiciary. They attack what they wish to control. In the end, the intention is to entrench conservatism in the courts, insulated even from the electoral tides.

This has happened before, of course.

When the Federalist Party -- the party of commercial interests and big government -- was defeated in the popular arena in 1800 with the election of Thomas Jefferson, its partisans sought to perpetuate their ideology by occupying the courts, the most aristocratic branch of government. Unlike the contemporary conservatives, the Federalists made no pretense of "populism."

More important, the foremost Federalist jurist, Chief Justice John Marshall -- who laid down the fundamental tenets of the Supreme Court -- addressed himself to the issues underlying the debate in the 1819 case, McCulloch v. Maryland, involving the right of Congress to charter a national bank.

The movement conservatives who want to invest themselves with the authority of the past will find cold comfort with thi founder.

Marshall's words ring with contemporary relevance: "We must never forget that it is a Constitution we are expounding . . . . This provision is made in a Constitution intended to endure for ages to come, and, consequently, to be adapted to the various crises of human affairs. To have prescribed the means by which government should, in all future time, execute its powers, would have been to change, entirely, the character of the instrument, and give it the properties of a legal code. It would have been an unwise attempt to provide, by immutable rules, for exigencies which, if forseen at all, must hae been seen dimly, and which can be best provided for as they occur."

Thus Meese's "jurisprudence of original intention" was refuted at the origin, rendering his premise invisible.