Cultural relativism argues that morality is determined by one's own culture rather than by universal truths. The document discusses how Eskimo customs like polygamy and infanticide differ greatly from Western practices but are accepted within their culture. However, cultural relativism is problematic as it implies no culture can judge another and there can be no moral progress. While cultures do differ, there are also universal values like protecting life that all societies share. Cultural relativism serves as a warning against ethnocentrism but does not preclude acknowledging improvements in treating humans.