Philosophers have written more about animal rights in the past twenty years than their predecessors wrote in the previous two thousand. Not surprisingly, disagreements abound. To begin with, among those who challenge the attribution of moral rights to animals are philosophers who operate within well-worn moral traditions in Western thought. Peter Singer (1975, and this volume, Chapter 9) and Carl Cohen (1986, 1996, 1997) are representative. 1 Singer follows in the tradition of the nineteenth-century English utilitarian Jeremy Bentham, who ridicules moral rights as ‘nonsense upon stilts’. For both Bentham and Singer, not only non-human animals but humans too lack moral rights. Half true, maintains Cohen. Animals, he argues, most certainly do not have moral rights; but Bentham and Singer err, in Cohen’s view, when they deny that humans have them. Nothing could be further from the truth: according to Cohen, not just some, all humans possess basic rights, including the rights to life and to bodily integrity.
As different as Singer and Cohen are in the conclusions they reach, they are importantly similar in how they approach the question of animal rights in particular and the more fundamental question of moral right and wrong in general. Both operate in what might be described as the Enlightenment tradition. Both assume that moral right and wrong are matters that in principle can be determined by the disciplined use of reason, just as both assume that the answers we seek must pay proper deference to the privileged moral position of certain individuals—individual human beings, in Cohen’s case; individual sentient beings, in Singer’s.
Despite their many differences, and easily lost in the storm of controversy, Singer and Cohen occupy common ground with philosophical advocates of animal rights (Pluhar, 1995; Regan, 1983; Rollin, 1981; Sapontzis, 1987). The latter also operate in the post-Enlightenment tradition; in other words, as is true of Singer and Cohen, philosophical advocates of animal rights also believe that moral right and wrong are matters that in principle can be determined by the disciplined use of reason and that the answers we seek must pay proper