Final answer:
Cultural relativism is unworkable because it lacks universal moral criteria, rendering it incapable of universally promoting tolerance, and because it disallows criticism of the majority's views by a minority, inhibiting moral progress.
Step-by-step explanation:
Two reasons why cultural relativism is an unworkable ethical theory are as follows:
Lack of universal moral criteria: Cultural relativism does not allow for universal moral criteria or absolutes, including tolerance. In some cultures, intolerance is seen as a positive value, and cultural relativism would mean that such intolerance is justified within those cultures. This undermines the potential for cultural relativism to promote tolerance universally.
Inability to criticize majority views: Cultural relativism posits that the predominant view within a society is inherently correct because it is the most widely held. This approach denies the validity of minority opinions and ignores the potential for moral progress that can stem from minority criticism of the majority, which has historically been a driver of ethical reforms.
Cultural relativism also fails to align with common human experiences that typically include some sense of universal moral wrongs, such as opposition to practices like female infanticide. This observable fact that there are some principles, such as the wrongness of unjustified killing, that are common across cultures suggests that there can be a basic set of ethical principles applying to all cultures.