Defining speciesism as "a failure, in attitude or practice, to accord any nonhuman being equal consideration and respect," this brilliant work critiques speciesism both outside and within the animal rights movement. The author demonstrates that much of the moral philosophy, legal theory, and animal advocacy aimed at advancing nonhuman emancipation actually perpetuate speciesism. Speciesism examines philosophy, law, and activism in terms of three categories: "old speciesism," "new speciesism," and species equality.Old-speciesists limit rights to humans. Speciesism refutes their standard arguments against nonhuman rights. Current law is old-speciesist -- legally, nonhumans have no rights. Dunayer shows that "animal laws" such as the Humane Slaughter Act afford nonhumans no meaningful protection. She also explains why welfarist campaigns are old-speciesist. Instead of opposing the abuse or killing of nonhuman beings, such campaigns seek only to make abuse or killing less cruel; they propose alternative ways of violating nonhumans' moral rights. Many organizations that consider themselves animal rights advocates engage in old-speciesist campaigns, which reinforce the property status of nonhumans rather than promoting their emancipation.New-speciesists espouse rights for only some nonhumans, those whose minds seem most like those of humans. In addition to devaluing most animals, new-speciesists give greater moral consideration and stronger basic rights to humans than they do to any nonhumans. They see animalkind as a hierarchy, with humans at the top. Dunayer explains why she categorizes such theorists as Peter Singer, Tom Regan, and Steven Wise as new-speciesists.Nonspeciesists advocaterights for every sentient being. Speciesism makes the case that every creature with a nervous system should be regarded as sentient. The book provides compelling evidence of consciousness in animals often dismissed as insentient -- such as fishes, insects, spiders, and snails. Dunayer argues that every sentient being should possess basic legal rights, including rights to life and liberty. Radically egalitarian, Speciesism envisions nonspeciesist thought, law, and action.