Animal Welfare: Assessment | 51 tionists from non-abolitionists who are still humanitarians In general, it is possible to consider animal welfare and animal rights using a common frame of reference We can envision animal rights as championing the full protection of all of animals’ vital interests Animal welfarists, by contrast, generally agree that only some interests should be protected (e.g., avoiding unnecessary suffering, although not avoiding premature death) Also, protection of interests usually occurs to a lesser degree in the case of animal welfarists as compared to animal rightists (e.g., humans generally have more freedom of movement than animals confined for industrial purposes) See also Animal Rights Movement, New Welfarism Further Reading Carson, Gerald 1972 Men, beasts, and gods: A history of cruelty and kindness to animals New York: Charles Scribner’s Sons Dunayer, Joan 2004 Speciesism Derwood, MD: Ryce Publishing Finsen, Lawrence, and Susan Finsen 1994 The animal rights movement in America: From compassion to respect New York: Twayne Jasper, James M., and Dorothy Nelkin 1992 The animal rights crusade: The growth of a moral protest New York: Free Press Regan, Tom 1983 The case for animal rights Los Angeles: University of California Press/ Regan, Tom 2004 Empty cages: Facing the challenges of animal rights New York: Roman & Littlefield Ryder, Richard D 1989 Animal revolution: Changing attitudes towards speciesism Oxford: Basil Blackwell Singer, Peter 1975 Animal liberation New York: Avon Books Sztybel, David 2006 The rights of animal persons Journal for Critical Animal Studies (1): 1–37 David Sztybel ANIMAL WELFARE: ASSESSMENT Assessment of animal welfare requires knowledge about the biology and psychology of animals—their needs and preferences, their responses to how they are treated, their perceptual and mental abilities, and their emotional states This knowledge allows us to better understand how animals perceive the impact of housing and management on their health and welfare, and hence helps us to make more informed decisions about animal welfare issues A central role of animal welfare science is to provide this information However, measuring the biological and psychological state of nonhuman animals is scientifically challenging In particular, the subjective emotional experiences of animals, such as pain, fear, and pleasure, that lie at the heart of most people’s concerns about animal welfare, are inherently private and therefore very difficult to assess Many scientists and philosophers argue that we may never know whether nonhuman species have conscious experiences, let alone measure what they might be, and some contend that we should therefore only assess welfare by investigating whether the animal’s biological functioning appears normal or impaired in some way Others argue that we need to develop measures that, although indirect, may be useful proxy indicators of subjective emotional states in animals, and some researchers believe that these states can be assessed directly Despite these differing views, animal welfare scientists have developed a number of methods to assess welfare that can be usefully split into two main approaches: the welfare indicators