But even if it had been possible to provide the Negro with equal facilities in terms of external construction and quantitative distribution we would have still confronted inequality. If it had been possible to give Negro children the same number of schools proportionately and the same type of buildings as white children, the Negro children would have still confronted inequality in the sense that they would not have had the opportunity of communicating with all children. You see, equality is not only a matter of mathematics and geometry, but it’s a matter of psychology. It’s not only a quantitative something but it is a qualitative something; and it is possible to have quantitative equality and qualitative inequality. The doctrine of separate but equal can never be.
From Martin Luther King, Jr., “Desegregation and the Future,” December 15, 1956.