WHAT SHOULD people make of the revisionist word coming out of the Reagan White House that black Americans were not so much helped as hurt by the Great Society effort of Lyndon Johnson? It is point-missing on a truly breathtaking scale.

Of course, there were errors and excesses in those programs. And it is surely also true that black Americans as well as white have been penalized by what particular unhappy economic effects may be traced to the errors and excesses of the Great Society. Blacks, like everyone else, benefit from a healthy economy. But everything has its cost; every choice -- if it deserves the name of a choice -- is about more and less important values, about what is an acceptable price for what. Maybe Mr. Reagan does not remember or care to consider what was different for blacks before that great mid-1960s burst of effort occurred. We will be happy to remind him.

More than a mere collection of costly programs was involved here -- much more. Yes, there was enacted long overdue legislation seeking to make equal opportunity -- in employment, housing, health care, education and legal rights -- a reality, as distinct from a Fourth of July talking point. But this was accompanied by an assertion of presidential respect for the dignity of the black Americans and by a wholehearted presidential commitment to securing for blacks equal treatment under the law -- and fast. That this should have been required of an American president in the mid-20th century was appalling. That Lyndon Johnson rose to the challenge remains perhaps the finest thing about his presidency.

Incidentally, one enormous "side benefit" for black Americans of the Great Society social programs was the fact that these programs made much-wanted funds available to jurisdictions that were, by the civil rights law enacted in 1964, compelled to desegregate their institutions to receive such funds. Blacks were admitted to white hospitals in the South, for example, in 1966 because that was the only way those hospitals could qualify for federal Medicare money.

We think Mr. Reagan's suggestion that the Great Society effort set back black people's progress in this country is very similar to an earlier suggestion that it's the trees that are responsible for the pollution. At best, it's a joke, at worst a travesty.