the kinds of things that disgust me most (child rape, slavery) are violations of personal integrity: the reduction of another's options to a deplorably unacceptable degree. if someone else does not find those things disgusting, I have no basis for discussing morality with them at all. if I were asked to explain why I find them repulsive to someone who disagreed, I cannot even enter that conversation because I and that person have no common understanding regarding humanity and decency at all.