An interesting article that approaches this question by examining the role of religious dictates, moral philosophies, reason, natural science among other point of view.
“Moral disputes seem intractable — more intractable than other disputes. Take an example of a moral position that most of us would consider obvious: Honor killing is wrong. But honor killing has its supporters. Anyone who suggests that we can compromise with its supporters on the matter misunderstands the nature of this type of disagreement. It’s absolute. One party has to be right. Us. So why can’t we convince those who hold the opposite view?”