Are these claims defensible? Katarzyna de Lazari-Radek and Peter Singer test them against a variety of views held by contemporary writers in ethics, and conclude that they are. This book is therefore a defence of objectivism in ethics, and of hedonistic utilitarianism. The authors also explore, and in most cases support, Sidgwick's views on many other key questions in ethics: how to justify an ethical theory, the significance of an evolutionary explanation of our moral judgments, the choice between preference-utilitarianism and hedonistic utilitarianism, the conflict between self-interest and universal benevolence, whether something that it would be wrong to do openly can be right if kept secret, how demanding utilitarianism is, whether we should discount the future, or favor those who are worse off, the moral status of animals, and what is an optimum population.