2012 Oxford University Press. R.M. Hare was one of the most important ethical theorists in the second half of the 20th century, and one of his graduate students, Peter Singer, became famous for his writings on animals and personhood. Singer now says that he endorses Hare's "two-level utilitarianism," and he has invoked the theory's distinction between "critical thinking" and thinking in terms of "intuitive level rules" in response to certain objections to his conclusions on several issues. For his part, however, Hare never published a systematic treatment of how his theory applies to issues in animal ethics, and he avoided talking about the concept of "personhood." This book defends the moral legitimacy of distinguishing among "persons," "nearpersons," and "the merely sentient" within Harean two-level utilitarianism, illustrates the implications of this distinction by applying the resulting ethical system to some issues regarding our treatment of animals, and emphasizes how the results contrast with the more abolitionist conclusions reached by Singer on these same issues. In the process, the book presents a new philosophical defense of two-level utilitarianism and its metaethical foundation (universal prescriptivism), and it significantly expands Hare's account of how "intuitive level rules" function in moral thinking, based on recent empirical research. The book also draws heavily on empirical research on consciousness and cognition in non-human animals as a way of approaching the question of which animals, if any, are "persons," or at least "near-persons."
