Personhood, Ethics, and Animal Cognition

R.M. Hare was one of the most important ethical theorists 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.