Animal Ethics

Work in animal ethics explores both theoretical questions about the basis of moral consideration for animals and what (if anything) we owe them, as well as practical issues relating to how we should treat them. The term “animal” technically refers to all members of the kingdom Animalia, which includes organisms with complex nervous systems such as mammals, birds, herpetofauna (reptiles and amphibians), and fishes but also includes many with simple nervous systems such as barnacles and nematodes. However, most of the literature in animal ethics, and the references cited in this article, focus on animals that are believed to be sentient: that is, they can have subjective experiences and lead a life that can go better or worse for them experientially. Almost everyone agrees that mammals and birds are sentient, and many argue that other vertebrates (e.g., fish and herpetofauna) are also sentient, but relatively few claim that many invertebrates (other than cephalopods) are sentient. Sentience is commonly claimed to give animals moral standing because, as subjects of conscious experiences, things matter to them. As Peter Singer put it in his landmark 1975 book Animal Liberation, if a being can experience suffering or enjoyment, then it can be harmed and benefited in morally significant ways. Since the 1970s, animal ethics has expanded in many different directions. First, it has become much more deeply informed by scientific work on animal behavior and cognition. This has helped in understanding both what matters to animals and in considering what might matter about them. Second, different theoretical positions in animal ethics have been carefully worked out, including utilitarianism and rights views, which dominated much of the early discussion, but also alternative approaches such as contract theory and ethics of care. Third, alongside general discussions of animals’ moral significance, there has been much deeper ethical exploration of different contexts in which humans encounter or live with animals such as in the wild, in agriculture, in zoos, as companions, or in laboratories. These different contexts have raised more practical, applied ethical questions. This article introduces some of the most important work in terms of the science influencing animal ethics, different theoretical approaches to animal ethics, and debates about what we owe to animals in different contexts.