Biotechnologies already on the horizon will enable us to be smarter, have better memories, be stronger and quicker, have more stamina, live longer, be more resistant to diseases, and enjoy richer emotional lives. To some of us, these prospects are heartening; to others, they are dreadful. In Beyond Humanity a leading philosopher offers a powerful and controversial exploration of urgent ethical issues concerning human enhancement. These raise enduring questions about what it is to be human, about individuality, about our relationship to nature, and about what sort of society we should...