  On a first read the Disfranchisement Premises appear to presuppose the conclusion they aim to show. They appeal to the effects of wrongs to make the case that blacks are fully human, and hence ought to have their civil rights protected. But whether the treatment of blacks counts as a wrong is the very question at issue. Of course, in contemporary legal contexts the issue doesn't even get started, since the fourteenth and fifteenth amendments (ratified after the Civil War) prohibit the denial of civil rights to blacks. During the slavery era, though, that point faced a stiff legal headwind, especially in slavery-related cases argued before the Supreme Court, and so positive arguments needed to be produced.