On the eve of the long-awaited first holiday honoring the Rev. Martin Luther King Jr. as a national hero, black Americans appear optimistic about the future, pleased with the dramatic gains some of them have made, but upset at the pace of progress for many and convinced that racial discrimination is still rampant in America.

A comprehensive new Washington Post-ABC News poll of 1,022 blacks indicates that blacks are grappling among themselves for the answers to thorny, deep-seated, personal issues. They reveal complex and sometimes contradictory feelings in response to each of these questions:

*Is discrimination responsible for blacks' economic and social shortcomings, or is it blacks' own lack of determination?

*Do government welfare programs really help the millions of blacks disproportionately dependent on them, or do they stifle self-improvement?

*Is government intervention, the legendary Great Equalizer of social justice, essential for black economic success, or can blacks go it alone?

The survey, conducted by telephone Jan. 7 to Jan. 14, evokes a black America of many faces. Some beam appreciatively from the gains of civil rights, voting rights, open housing, economic opportunity, affirmative action -- "No more Jim Crow." Others, however, peer from behind sullied masks of chronic unemployment, stubborn poverty, shattered families, low self-esteem and little hope.

Yet the poll found that, behind those different faces, blacks hold remarkably homogeneous views on a range of issues. The answers to questions in this poll were similar regardless of income, age, education, gender, geography -- all the usual dividers of public opinion.

The Post-ABC poll found fears of lingering and widespread racism, increased discrimination and impending economic decline side by side with proclamations of optimism about the black future in America, strong educational and economic gains and a firm belief that chronic poverty can be eliminated in America.

The poll also illuminated a significant difference between blacks' perceptions of the conditions of blacks generally, and of their own lives. They appear more optimistic about themselves than about their group. For instance, 48 percent said they think income and living conditions are worsening for most blacks, while only 14 percent think they are improving. But twice as many -- 28 percent -- said things are getting better for them personally, and only 23 percent said they are getting worse.

It was August of 1963 when King stood on the steps of the Lincoln Memorial here and declared, "Now is the time to open the doors of opportunity to all of God's children. Now is the time to lift our nation from the quicksands of racial injustice to the solid rock of brotherhood."

Today, nearly 23 years later, the poll found a solid majority of blacks who said blacks in their neighborhoods are receiving as good an education as whites, 41 percent who professed that it is "not difficult at all" to make ends meet in these tough economic times and lopsided majorities who said school integration has been good for black education and made black children feel better about themselves.

King also said that day, however, that "1963 is not an end, but a beginning" and the results of the Post-ABC poll suggest that, just as accurately as then, 100 years after the signing of the Emancipation Proclamation, King could today declare, "The Negro is still not free."

Half to two-thirds of those interviewed said blacks are discriminated against in getting decent housing, skilled and unskilled jobs and just wages. Nearly eight of 10 said whites do not want blacks to get ahead.

One of three said that among whites as a group there is "a great deal of prejudice" toward blacks. Six of 10 said at least one-tenth of America's white population shares the attitudes of the Ku Klux Klan, and 23 percent of the blacks polled said more than half of America's whites belong in that category.

Yet the bottom line among those blacks interviewed was as optimistic as one other King proclamation of that day: "We refuse to believe that there are insufficient funds in the great vaults of opportunity of this nation."

"Thinking of the future," the Post-ABC poll asked, "All in all would you say that life for blacks in this country will be better, about the same, or worse than it is now?"

Fifty-seven percent answered "better," 23 percent said "about the same" and 15 percent said "worse."

The poll, directed by Post pollster Barry Sussman and colleagues from ABC News, was one of the most extensive of black Americans in recent years. It sampled seven to 10 times as many blacks as are usually contacted in national opinion surveys of Americans of all races. All the questioners who conducted the poll were black.

Some of the findings portrayed a collective black community less optimistic than found in earlier surveys. In the new poll, for example, blacks' view of the nation's economic future is at its lowest point since the depth of the recession in 1982. Then, 4 percent said the economy was getting better, 78 percent said it was getting worse and 18 percent saw things staying the same.

Now, 11 percent anticipate improvement, 53 percent foresee a decline and 33 percent expect things to stay the same. Only a year ago, black optimism hit a high point, as 18 percent said the economy was getting better, 52 percent said it was staying the same and 27 percent saw it getting worse.

Black Americans interviewed this month see more discrimination today in education, housing, jobs and wages than in a Post-ABC poll of a relatively large sample of blacks in 1981. In the past five years, moreover, they have switched sides on the question of affirmative action, becoming substantially more supportive of a position the Reagan administration has argued against, the poll found.

In 1981, by a 49-to-41 plurality, blacks disagreed with this statement: "Because of past discrimination, blacks who need it should get some help from the government that white people in similar economic circumstances don't get." In the latest poll, 50 percent agreed and 38 percent disagreed.

In many respects, America is far different today from the nation King knew before his death on a Memphis motel balcony on April 4, 1968.

In assessing that progress, 37 percent of the blacks interviewed cited "a decrease in white prejudice" as a major reason why "many blacks these days have jobs or positions that were open to only a few blacks years ago." Forty-one percent said government financial aid was also a major reason.

About half of the respondents said "federal government laws and court decisions ending formal racial segregation" and "younger blacks asserting their rights" were major reasons.

The biggest credit, however, went to "an increase in education for many blacks" and "hard work and determination by blacks." Each was considered a major reason by seven of every 10 respondents.

Still, 56 percent said blacks have been helped by "a number of assistance programs for poor people" begun by the government "in the 1960s and 1970s." Only 15 percent said those programs hurt; 21 percent said they made no difference.

Asked about the inevitability of a black "underclass," only 29 percent said their view is best expressed by saying, "There will always be many blacks living in extremely bad conditions no matter how much effort is made to change that."

By contrast, 66 percent agreed that "With enough effort, those extremely bad conditions can be almost entirely eliminated." Five percent had no opinion.

Respondents to the new poll were sharply divided on questions about blacks themselves.

Asked, for instance, whether, "on the average, blacks have worse jobs, income and housing than whites" because "most blacks don't have the motivation or willpower to pull themselves out of poverty," 50 percent said, "No," 45 percent said "Yes" and 5 percent had no opinion.

Respondents were asked to agree or disagree with the following statement: "Discrimination has unfairly held down blacks, but many of the problems which blacks in this country have today were brought on by blacks." Forty-seven percent agreed, 44 percent disagreed and 9 percent had no opinion.

The Post also asked whether "government welfare programs mainly discourage people from improving themselves, or . . . mainly help people until they begin to stand on their own?" In this instance, 47 percent said the programs discouraged, 40 percent said they helped and 13 percent had no opinion.

There was a nearly even three-way split when respondents were asked to agree or disagree with this statement: "There's no excuse for anti-Semitism, but much of the anti-Jewish feeling in this country today has been brought on by Jews themselves." Thirty-two percent agreed, 37 percent disagreed and 31 percent offered no opinion. In the 1981 Post-ABC poll, 25 percent agreed with that statement.

Respondents were asked to evaluate antiblack feelings among whites and various ethnic groups. Thirty-five percent said there is "a great deal of prejudice" among whites; 46 percent said "a fair amount."

Sixteen percent said that among Jews there is "a great deal" of antiblack prejudice; 39 percent said "a fair amount" and 19 percent "not much." Poll respondents gave an almost identical assessment of antiblack feelings among blacks themselves. Eighteen percent said blacks hold "a great deal" of antiblack feeling, 32 percent said "a fair amount" and 21 percent "not much."

Asked about Hispanics, 13 percent of respondents said they harbor a "great deal" of antiblack prejudice, 26 percent a "fair amount" and 27 percent "not much" at all. Among Asian-Americans, 14 percent of those polled said there is a "great deal" of bias, 28 percent a "fair amount" and 21 percent "not much."

The strongest self-criticism came on the question of whether "most blacks who are well off financially tend to do as much as they should to help improve conditions for poorer blacks." Here, 80 percent responded "not as much," 15 percent "as much as they should" and 5 percent gave no opinion.

For decades, black Americans have looked to education as the major engine for personal advancement, and the Post-ABC poll confirmed not only the persistence of that belief, but also a sense that blacks have made considerable gains in that cherished area.

Not only was increased education cited most frequently as the reason for black success. Lack of "the chance for the education it takes to rise out of poverty," along with discrimination, was the most popular explanation for why blacks have worse jobs, income and housing than whites. Two-thirds of those polled blamed absence of educational opportunity for the difference.

Blacks' views varied somewhat depending on their income, age and other factors. For example, those with higher household incomes were more likely to foresee economic improvement than poorer blacks. Younger blacks, 18-30, generally were more optimistic than blacks aged 61 or older. Blacks with more education tended to express less self-confidence than those with less education.

Some differences appeared to challenge conventional wisdom. Blacks with the most educational achievement, those who attended college and held degrees, were more inclined than others to reject the assertion, "If blacks would try harder, they could be just as well off as whites."