Chapter 19 marks the beginning of Part 3 on metaethics. It explores two theories that question the status of ethics. The lack of belief in the existence of objective moral standards is called moral skepticism. The theory can take two forms: moral nihilism, which argues there is no moral truth at all, and ethical relativism, which asserts that moral truths are not objective but rather relative to individuals or societies.

Chapter 19 explores the theory of ethical relativism. It can take two forms: cultural relativism and individual relativism (also called ethical subjectivism). The first claims cultures and societies determine which moral standards are true. The second claims that moral standards are relative to every individual. There are several advantages to cultural relativism and ethical subjectivism. First, they cater to the human experience, either on a societal or an individual scale. Second, they are straightforward: Morality is what any individual or society deems acceptable. Third, they can easily identify individuals and societies as the ultimate source of moral knowledge. Finally, they are egalitarian because almost everyone is considered a good judge of morality and everyone’s opinions are equally valid.

Relativism and subjectivism are both flawed since societies and individuals can be mistaken about morality.