People with Cognitive Disabilities: The Argument from Marginal Cases and Social Work Ethics

"What if an ape had the intelligence and sensibilities of a human, and a human had only the capabilities of an ape? Which would be the human being? The answer is plain; the ape would be the human being" (Fletcher, 1976, p. 62). Beginning with Singer's early writings on animal liberation in the 1970s, the Argument from Marginal Cases (AMG) has been an important philosophical argument buttressing calls for increased public consideration of animal rights. In January 2000 Social Work introduced its readers to this issue in a commentary by Wolf (2000) entitled "Social Work and Speciesism." Although Wolf did not discuss the AMC in depth, such an exploration is important for social workers. Proffered by animal rights proponents over the past few decades, the AMC has the potential to denigrate the status of many of the groups to which the social work profession should be most committed. By comparing "marginal" humans to animals, the AMC may unwittingly dehumanize people with cognitive disabilities and be yet another way our society justifies maltreatment of its most vulnerable members. Speciesism and the Argument from Marginal Cases Singer (1975) initiated what would later become known as the Argument from Marginal Gases in his book Animal Liberation, often referred to as the "bible" of the animal rights movement. In the book Singer argued that "if we examine more deeply the basis on which our opposition to discrimination on grounds of race or sex ultimately rests, we will see that we would be on shaky ground if we were to demand equal rights for blacks, women, and other groups of oppressed humans while denying equal consideration to nonhumans" (p. 3). According to Singer and many other animal rights scholars, there is no morally defensible justification for protecting marginal humans (those with severe cognitive disabilities) while perpetuating abuse or neglect against nonhuman animals if both function at similar "intellectual" levels (Anstotz, 1993; Dombrowski, 1997; Pluhar, 1995; Ryder, 1991; Singer, 1975, 1979). As Frey (1983) wrote, "[I]f the value of a life is a function of its quality, then as its quality diminishes, its value dim inishes." In cases of severe mental disability, he continues, the quality and value of human life... can approach and even fall below the "quality of life of some quite ordinary animals" (p. 111). To provide moral consideration to the former only because they are members of the species Homo sapiens, it is argued, is "speciesist" and "homocentrist" (Pluhar; Ryder). Animal rights proponents especially view the great apes (that is, gorillas, chimpanzees, and orangutans) as deserving of enhanced moral status (Cavalieri & Singer, 1993). The communication experiments with Washoe, Koko, and other apes reinforced the notion that these animals engage in a degree of rational thought. Patterson and Linden (1981) noted that in IQ tests they administered to Koko, she "scored consistently in the 70 to 90 range" (p. 127). This exceeds the IQ of virtually all people diagnosed as having mental retardation. The kinship of humans to apes, as characterized not only by taxonomic standing, but also by the fact that we share more than 98 percent of our genetic structure with them, has also been cited as justification for the enhanced moral consideration of these other simians (Goodall, 1993; Pluhar, 1995). Although used to support vegetarianism and make a case against a host of animal rights abuses, the AMG has been most useful to opponents of animal experimentation. A century ago, writing in the International Journal of Ethics, Salt (1899-1900) noted that It may be asked of the great bulk of physiologists, who indignantly repudiate the idea of vivisecting human beings, but are equally emphatic in their justification of experiments on animals, on what grounds they base this difference in their ethical principles? ... If a mere difference in degree of sensibility and intelligence is held to be the justification, there must be equal sanction for the sacrifice of a savage or a criminal. …