What is The Moral Landscape about?

The Moral Landscape is Sam Harris's argument that science can and should determine human values. The provocative central claim is that moral questions are not fundamentally different from empirical questions: both are questions about the wellbeing of conscious creatures, and both can in principle have objectively better and worse answers. Just as medicine can say some states of health are objectively better than others, Harris argues that moral philosophy can say some states of human flourishing are objectively better than others — and that science is the tool best equipped to investigate them.

Harris's target is the widespread assumption, shared by religious conservatives and secular relativists alike, that science and morality occupy separate domains. He attacks the is-ought distinction associated with Hume, arguing that it does not actually prevent scientific investigation from bearing on moral questions once you accept that the wellbeing of conscious beings is what morality is about. He also argues against moral relativism: the claim that all cultures' moral systems are equally valid is not a liberal tolerance but an intellectual evasion that prevents clear thinking about genuine ethical catastrophes.

The second half of the book applies this framework to a series of specific cases. Harris argues that certain religious and cultural practices — female genital mutilation, honor killing, beliefs that produce chronic psychological suffering — are objectively wrong in the same way that medical neglect is objectively wrong. He acknowledges that the science of wellbeing is primitive and that the moral landscape will be difficult to map precisely, but insists that difficulty in answering a question does not mean the question has no correct answer.

The Moral Landscape generated substantial philosophical criticism. Many philosophers argued that Harris misrepresents Hume, conflates different senses of "wellbeing," and simply assumes rather than proves that wellbeing is what morality is about. Harris largely acknowledged the latter criticism as correct but immaterial: if you reject wellbeing as the foundation of ethics, he asks, what are you actually concerned about? The book is most useful as a clear attack on moral relativism and a defense of the idea that rational discourse about ethics is possible and worthwhile.