The "whither black America" debate has been going on for some time now -- in earnest conversations among friends, in heated living-room arguments, in privately expressed doubts of the prevailing orthodoxies.

Its occasional public manifestations, until recently, hardly qualified as debates at all. Some black conservative -- a Thomas Sowell or a Walter Williams -- would say something that, even though it may have made theoretical sense, was said in such a way that it lacked political sense. That is, it would sound less like a prescription for solving problems than an attack on the established black leadership, and the rest of us would respond not by debating the issue but by dissecting those who posed it.

That is starting to change, and the result could be as historically significant as the Booker T. Washington-W.E.B. Dubois debates of an earlier time. As with those intellectual giants, the questions are not over truth versus falsehood. The disputants recognize that there is truth on both sides. The emerging debate is over emphasis: What is the most pressing problem in a panoply of problems? What strategies are more likely to lead to a solution?

Take the raging controversy over teacher testing. Everybody recognizes that there is a tangle of problems: black children, particularly those from low-income families, aren't learning as well as they can. And one reason why they aren't is that their teachers aren't as competent as they might be.

But teacher testing, the method some 30 states have adopted as the means of improving teacher competency, works disproportionately against black teachers. Should our emphasis be on black students, who will face a grim future if they fail to get a proper academic footing, or on black teachers, who would face unemployment right now?

It isn't just a theoretical question. Black teen-age unemployment is a national disgrace, and one of the reasons why is that too many black youngsters are leaving school as functional illiterates.

On the other hand, attempts to remedy the situation by insisting on higher standards of competency for teachers introduce another problem. According to G. Pritchy Smith, a professor of education at Jarvis Christian College in Texas, teacher-competency tests would reduce the proportion of black teachers from the present 12.5 percent to less than 5 percent in the next decade.

The tests may not be consciously racist, and ther implementation may not be designed to screen out blacks, Smith acknowledged in an interview with the Associated Press. "But it's hard not to call it racism when you know the result in advance."

And the results are alarming. Ninety percent of the whites who took the Florida competency test in 1983 passed it; only 35 percent of blacks did. In California, the pass rate was two-thirds whites, just over a quarter for blacks; in Georgia, 87 percent for whites, 34 percent for blacks.

Some of the blacks in the debate believe that standardized tests are intrinsically racist, and that they do not truly measure competency. Others, including a growing number of black school administrators, say that while they are distressed at the disproportionate racial impact of the tests, the real problem is not the tests but the preparation of the prospective teachers. In any case, they argue, it's unrealistic to expect black children to learn to pass the tests that will get them into quality colleges and decent jobs if their teachers can't pass such tests.

A short time ago, the issue -- at least in the black community -- would have been resolved, without any real public argument, in favor of the black teachers.

Today, the outcome is anybody's guess.