Slavery in America was perpetuated not merely by human badness but also by human blindness. ... Men convinced themselves that a system that was so economically profitable must be morally justifiable. ... Science was commandeered to prove the biological inferiority of the Negro. Even philosophical logic was manipulated [exemplified by] an Aristotlian syllogism: All men are made in the image of God; God, as everyone knows, is not a Negro; Therefore, the Negro is not a man.