''Go into any inner-city neighborhood,'' Barack Obama said in his keynote address to the Democratic National Convention, ''and folks will tell you that government alone can't teach kids to learn. They know that parents have to parent, that children can't achieve unless we raise their expectations and eradicate the slander that says a black youth with a book is acting white.'' In a speech filled with rousing applause lines, it was a line that many black Democratic delegates found especially galvanizing. Not just because they agreed, but because it was a home truth they'd seldom heard a politician say out loud.

Why has it been so difficult for black leaders to say such things in public, without being pilloried for ''blaming the victim''? Why the huge flap over Bill Cosby's insistence that black teenagers do their homework, stay in school, master standard English and stop having babies? Any black person who frequents a barbershop or beauty parlor in the inner city knows that Mr. Cosby was only echoing sentiments widely shared in the black community.

''If our people studied calculus like we studied basketball,'' my father, age 91, once remarked as we drove past a packed inner-city basketball court at midnight, ''we'd be running M.I.T.'' When my brother and I were growing up in the 50's, our parents convinced us that the ''blackest'' thing that we could be was a doctor or a lawyer. We admired Hank Aaron and Willie Mays, but our real heroes were people like Thurgood Marshall, Dr. Benjamin Mays and Mary McLeod Bethune.

Yet in too many black neighborhoods today, academic achievement has actually come to be stigmatized. ''We are just not the same people anymore,'' says the mayor of Memphis, Dr. Willie W. Herenton. ''We are worse off than we were before Brown v. Board,'' says Dr. James Comer, a child psychiatrist at Yale. ''And a large part of the reason for this is that we have abandoned our own black traditional core values, values that sustained us through slavery and Jim Crow segregation.''