Cass Sunstein and Martha Nussbaum bring together an all-star cast of contributors to explore the legal and political issues that underlie the campaign for animal rights and the opposition to it. Addressing ethical questions about ownership, protection against unjustified suffering, and the ability of animals to make their own choices free from human control, the authors offer numerous different perspectives on animal rights and animal welfare. They show that whatever one's ultimate conclusions, the relationship between human beings and nonhuman animals is being fundamentally rethought. This book offers a state-of-the-art treatment of that rethinking.