“Racial considerations intruding upon the educational process contaminate education at the source,” Kenneth Clark wrote in these pages in 1979. As an African-American and the son of a trade-union shop steward, Clark believed in equality. As a psychologist, he believed in evidence. It was the combined commitment to evidence and equality that lent his studies on children of segregated schools such authority they became the basis for the Supreme Court’s Brown v. Board of Education decision. Until his death on May 1, just shy of Brown‘s fifty-first anniversary, Clark remained fiercely attached to those principles. By every measure he was able to define–children’s self-esteem, students’ performance on tests, flow of education dollars–separate-but-equal remained for Clark “a contradiction in terms for blacks,” even when expressed through such institutions as historically black colleges. His unwavering dedication to the core analysis of Brown led him to condemn, at various junctures, African-American separatism, Jewish racism, New York community school boards and liberal white intellectuals who “have lost all empathy with low-income people and black people.” Clark was as hard on his own early naïve optimism, and he understood that the courts, Justice Department and some black leaders long ago wrote off the Second Reconstruction promised by Brown. But he refused any intellectual accommodation with resegregation. Kenneth Clark was one of the country’s great truth-tellers.