Most ethicists reject the theory of ethical relativism. Some claim that while the moral practices of societies may differ, the fundamental moral principles underlying these practices do not.
For example, in some societies, killing one’s parents after they reached a certain age was common practice, stemming from the belief that people were better off in the afterlife if they entered it while still physically active and vigorous. While such a practice would be condemned in our society, we would agree with these societies on the underlying moral principle — the duty to care for parents. Societies, then, may differ in their application of fundamental moral principles but agree on the principles.
Also, it is argued, it may be the case that some moral beliefs are culturally relative whereas others are not. Certain practices, such as customs regarding dress and decency, may depend on local custom whereas other practices, such as slavery, torture, or political repression, may be governed by universal moral standards and judged wrong despite the many other differences that exist among cultures. Simply because some practices are relative does not mean that all practices are relative.
Other philosophers criticize ethical relativism because of its implications for individual moral beliefs. These philosophers assert that if the rightness or wrongness of an action depends on a society’s norms, then it follows that one must obey the norms of one’s society and to diverge from those norms is to act immorally. This means that if I am a member of a society that believes that racial or sexist practices are morally permissible, then I must accept those practices as morally right. But such a view promotes social conformity and leaves no room for moral reform or improvement in a society. Furthermore, members of the same society may hold different views on practices. In the United States, for example, a variety of moral opinions exists on matters ranging from animal experimentation to abortion. What constitutes right action when social consensus is lacking?
Perhaps the strongest argument against ethical relativism comes from those who assert that universal moral standards can exist even if some moral practices and beliefs vary among cultures. In other words, we can acknowledge cultural differences in moral practices and beliefs and still hold that some of these practices and beliefs are morally wrong. The practice of slavery in pre-Civil war U.S. society or the practice of apartheid in South Africa is wrong despite the beliefs of those societies. The treatment of the Jews in Nazi society is morally reprehensible regardless of the moral beliefs of Nazi society.
For these philosophers, ethics is an inquiry into right and wrong through a critical examination of the reasons underlying practices and beliefs. As a theory for justifying moral practices and beliefs, ethical relativism fails to recognize that some societies have better reasons for holding their views than others.