This paper is divided into three sections. First, I describe the wide plurality of views on issues of animal ethics, showing that our disagreements here are deep and profound. This fact of reasonable pluralism about animal ethics presents a political problem. According to the dominant liberal tradition of political philosophy, it is impermissible for one faction of people to impose its values upon another faction of people who reasonably reject those values. Instead, we are obligated to justify our political actions to each other using reasons that everyone can accept. Thus, in the second section I suggest that our condition of reasonable pluralism inspires us to turn toward some form of contractarianism. The social contract tradition emerg...