The Great Society was the stunning achievement of interventionist government. It reduced U.S. poverty by two-thirds. It spawned a bloodless revolution that gave blacks the franchise, the full protection of the law and genuine political power. So potent is its legacy that not even Ronald Reagan, the most antigovernment president in modern history, dares tamper with its fundamental components.

The Great Society was an abysmal failure. It never made a dent in the incidence of poverty. Its compassionate ideals were co-opted by the medical profession and the middle-class providers of social services, who profiteered at the expense of ill-conceived and badly administered programs. It ignited massive inflation. It replaced historic racism with a more pernicious form of racial condescension wrapped in good intentions. Thanks to the Great Society, blacks must compete as blacks, not as individuals.

With an abundance of intellectual passion, those viewpoints were set forth today at the Lyndon B. Johnson School of Public Affairs at the University of Texas during a debate among liberal defenders and conservative critics of a set of laws, enacted a generation ago, known as the Great Society.

Though the symposium was entitled "The Great Society: A Twenty Year Critique," its participants sometimes seemed more preoccupied with critiquing "Losing Ground," the controversial new book by Charles Murray. He argues that by changing the "rules of the game" in a variety of legislative, regulatory and cultural ways, the Great Society "made it profitable for the poor to behave in the short term in ways that were destructive in the long term."

Murray, a senior fellow at the Manhattan Institute for Policy Research, was one of three conservatives on today's concluding seven-member panel discussion. There were plenty of hard shots, and Murray gave as good as he got.

At one level, the debate focused on what the Great Society was, and what it was not.

The liberal alumni of the Johnson Era pressed for a strict historical interpretation.

It was, they said, a package of legislation -- the Voting Rights Act, Medicare, Medicaid, the Job Corps, Title I of the Elementary and Secondary Education Act, Head Start, college-loan measures and housing-subsidy acts -- that achieved a remarkable, though unfinished, amelioration of inequality of opportunity.

"Ask the 11 million Americans who have received loans for their college education . . . . Ask the 4 million blacks who registered to vote in 11 southern states and the 6,000 blacks who held elective office in 1984 . . . . Ask the 8 million children who have been through Head Start . . . if the Great Society failed," said Joseph A. Califano Jr., former special assistant to President Johnson and the secretary of Health, Education and Welfare under President Jimmy Carter.

Califano credited Medicare and Medicaid with increasing life expectancy in the country by five years, from 70 to 75, and said those programs and the minimum-payment requirements of the Social Security Act had helped to assure that the elderly are no poorer than the population at large.

"We have had a decline of poverty from 22 percent in 1959 to between 7 and 8 percent in 1984," said political scientist Ben Wattenberg. "That's not failure."

"We succeeded because we threw money at these problems," he added. "When you throw money at problems, it helps. But it does cause a secondary order of problems, and dependency is one of them."

Califano and Wattenberg's litany was attacked by conservatives on two fronts. Allen Matusow, dean of humanities at Rice University, said that the only legitimate measure of poverty is relative deprivation, and that by that standard, nothing has changed in 20 years: The bottom 20 percent of society still receives just 5 percent of the total income.

Murray argued that the civil rights movement already had built a head of steam in the early 1960s, and that blacks, like oppressed minorities before them, were in the process of "taking what was rightfully theirs."

But, he continued, "we got in the way of" that process. "Whites put up a new kind of 'Whites Only' sign," he said. "They said, 'It's all our fault. Let us make it up to you,' " and in so doing, "they emasculated the blacks."

He ticked off a series of examples. In inner-city schools, he said, there was no standardized testing because it was judged to be culturally biased, and there was an avalanche of social promotion because the disadvantaged blacks were considered too fragile to be allowed to fail.

All black students suffered as a result, he said. Crime was allowed to flourish in the inner city, with poor blacks as the main victims, because society took a kid-gloves approach to punishing disadvantaged perpetrators, he said. No one whispered about the problem of illegitimate children in the black community because they were too busy celebrating the heritage of the strong extended black family, he said. Meanwhile, quotas or their equivalents were enacted, making whites resentful and suspicious of blacks who fought their way into the middle class.

Now it was Wattenberg's turn to counterattack.

"We never passed a 'Soft on Crime Act of 1966' or a 'Permissive Curriculum Act of 1967,' and there were no Great Society laws that dealt with busing or quotas," he said. "The only failure of the Great Society," he said, "has been its failure to dissociate itself from subsequent ideas labeled as liberal," rightly unpopular because they strive for equality of result rather than equality of opportunity.

"That's a cop-out," parried Stuart Butler, director of domestic policy studies of the Heritage Foundation. "You [the architects of the Great Society] created a vehicle, you gave the keys to someone else, and then you say it's not your fault for whatever happened . . . . I'm prepared to take it on on the chin for the Defense Department, if you'll take it on the chin for the Great Society."