He may no longer be young, but he is gifted and black. He is a Harlem high school dropout who later went on to graduate from Harvard with high honors. An economist, he is much admired by white consevatives and the idea men on the Reagan transition team. But mere mention of his name sends black civil rights leaders into a sputtering rage.

The name is Thomas Sowell, and in the great game of speculation about the Regan Cabinet it keeps coming up -- as a potential choice for secretary of the Department of Housing and Urban Development, member of the president's Council of Economic Advisers or secretary of labor.

In a telephone interview from California, where he is now a senior fellow at the conservative Hoover Institution at Stanford University, Sowell recalled a joke about him and the Cabinet rumors.

"Someone was saying if I was named secretary of labor, people would be jumping out of windows at the Labor Department the way they were jumping out of buildings on Wall Street in 1929. The person added that, unfortunately, the buildings in Washington aren't very tall."

The reason for all the uproar is Sowell's philosophy. In provocative arguments in a score of books and articles, Sowell has outlined his opposition to principles held dear by liberals and civil rights groups. He is against busing for school desegregation, rent control, the minimum wage and, in what may be the ultimate heresy to the civil rights groups, he argues that affirmative action programs have had the unintended effect of hindering rather than advancing the status of blacks.

"We would view with considerable concern the appointment of Tom Sowell to HUD or, for that matter, to any other Cabinet position," said Thomas I. Atkins, general counsel of the NAACP. "He would play the same kind of role which historically the house niggers played for the plantation owners. He could mete out the straight discipline. No matter how inhumanely administered, [it] would be presumed more acceptable because the hands of the disciplinarian are black."

Sowell misses not a beat before responding: "I think the NAACP are the classic house niggers. Their support comes from the white liberals in the press and philanthropy, and they are constantly taking positions the very opposite of the black community on crime, on quotas, on busing. What I think is tragic is that the media has bought their position."

Whether Sowell ultimately comes to Washington or not, his books and articles are likely to be an important element in the coming domestic policy debate as the new conservative administration reexamines and searches for cuts in the social programs of the New Deal and Great Society. He shares with the incoming administration a free-market philosophy. He views government actions that seek either to restrain or uplift with, at best, skepticism.

In his writings, he tends to carefully marshal arguments and facts that dispute the conventional wisdom rather than to offer any detailed new strategies for black advancement. Still, there is implicit in his works a good deal of the bootstrap philosophy.

Writing in "Race and Economics," published in 1975, he said: "The greatest dilemma in attempts to raise ethnic minority income is that those methods which have historically proved successful -- self-reliance, work skills, education, business, experience -- are all slow developing, while those methods which are direct and immediate -- job quotas, charity, subsidies, preferential treatment -- tend to undermine self-reliance and pride of achievement in the long run."

He has forcefully attacked the arguments of white conservative academics who suggest that blacks may be genetically inferior because of their relatively low scores on I.Q. tests. He presents evidence that the test results of other immigrant groups had been low initially but rose as their social and economic status improved.

Sowell agrees with black civil rights leaders that racial discrimination historically held blacks back, making advancement harder for them than any other American racial or ethnic group. He cheers the Supreme Court decisions and new laws that swept away Jim Crow regulations, but from there on he parts company with black civil rights leaders and their white liberal allies.

His targets are the array of social programs and policies for black advancement that followed the riots of the late 1960s. The so-called federal self-help programs, he argues, have either not helped the poor or made them less self-reliant and more dependent on the government.

What Sowell has written most about are the affirmative action programs, which he says have backfired. Instead of producing more jobs for women and blacks, he says, they have made potential employers more wary, fearful that if the hiring does not work out, they will probably be faced with a lawsuit.

And he says that skin color is no longer an unscalable barrier to advancement.

The NCAAP's Tom Atkins responds vehemently. "It's true that Tom Atkins and Tom Sowell don't need affirmative action programs to assist our entry into the mainstream. And it is also true that both Tom Atkins and Tom Sowell are, when compared to the average white person, exceedingly more qualified and more prepared. We're super-blacks. The NAACP approach is not one designed to assist the elitist or superblack; we worry about the whole spectrum. Tom Sowell apparently does not know they exist.

"Tom Sowell writes as though racial discrimination is a figment of somebody's imagination," Atkins said.

To which Sowell responds: "I think the difference between me and the civil rights groups on this subject is not so much a difference of philosophy as a difference in facts. I find them very uninterested in facts."

"If you ask me if I think racism has disappeared, I would say no. If you ask me to explain the difference between black income and white income, I would give less weight now to racism than I would have [before] doing massive amounts of research on this subject."

There has always been a debate over "Who Really Speaks for Black America" and which of the competing would-be spokesmen truly lived "The Black Experience," and it is no different in the running quarrel between Sowell and the civil rights groups.

"I always get the question, did you come from an affluent, middle-class background?" Sowell said. "It never occurs to them that perhaps the Andrew Youngs and the Thurgood Marshalls came from middle-class backgrounds."

Sowell was, in fact, born 50 years ago in Gastonia, N.C., of parents whom he will describe only as "low-skilled workers." He spent most of his first nine years in Charlotte, then moved with his parents to the tenements of Harlem in the great black migration to the North of the late 1930s and 1940s.

He described himself as a good student but said he dropped out of high school and went to work for four years with the legions stuck in low-skilled, deadend jobs in New York, finding work as a factory laborer, messenger for Western Union, delivery boy in the garment district.

In later years, he said, he came to look on that time as enormously valuable, helping him avoid disdain for menial labor but teaching that there was very limited demand for a black high school dropout with no skills and no contacts.

Uncle Sam called and he went off to the Marines. When he got out he went to Howard for two years, then transferred to Harvard.

"The worst time I ever had was my first term at Harvard," he told an interviewer a decade after he left Cambridge with a magna cum laude degree. "But thank God, there weren't any bleeding hearts around in those days and I finally made it on my own."

From Harvard he went to the University of Chicago, where he got a Ph.D, working under conservative economist Milton Friedman. He was teaching in Cornell's economics department in the late 1960s during the period immortalized in the Newsweek cover showing black students emerging from a building with rifles under their arms.

In that atmosphere, Sowell found himself at odds not only with black students over black studies programs and the rigor of academic requirements but also with white faculty and administrators who he felt unwisely yielded to the students' demands. Abruptly he quit and went to the University of California, where he began his still continuing inquiry into the broad subjects of race, achievement and economics.

Now he is a senior fellow at the Hoover Institution, citadel for conservatives and a recruiting ground for the Reagan administration.

Though he seems to relish combat with civil rights groups, he wants to make clear that is is an argument over means, not ends.

"Insofar as stamping out bigotry furthers our ends," he says, "let's do it but let's not make the moral regeneration of white people our No. 1 priority. One big reason is that this is the slowest gradualism imaginable. When you consider that it's been 2,000 years since the Sermon on the Mount and how little progress has been made in accepting it, you realize that blacks have to advance at a much faster rate than that."