What is ethics? Where does it come from? Can we really hope to find any rational way of deciding how we ought to live? If we can, what would it be like, and how are we going to know when we have found it? To capture the essentials of what we know about the origins and nature of ethics, Peter Singer has drawn on anthropology, evolution, game theory, and works of fiction, in addition to the classic moral philosophy of such thinkers as Nietzsche, Kant, and Confucius. By choosing some of the finest pieces of writing, old and new, in and about ethics, he conveys the intellectual excitement of the search for answers to basic questions about how we ought to live. From the debates of Socrates and the profound writing of Rousseau to Jane Goodall's reflections on the ethics of chimpanzee kinship and Luther's commentary on the Sixth Commandment (thou shalt not kill), this engaging reader offers a complete and thorough introduction to the fascinating world of ethical debate.