Biology and politics have converged today across much of the industrialized world. Debates about genetically modified organisms, cloning, stem cells, animal patenting, and new reproductive technologies crowd media headlines and policy agendas. Less noticed, but no less important, are the rifts that have appeared among leading Western nations about the right way to govern innovation in genetics and biotechnology. These significant differences in law and policy, and in ethical analysis, may in a globalizing world act as obstacles to free trade, scientific inquiry, and shared understandings of human dignity. In this magisterial look at some twenty-five years of scientific and social development, Sheila Jasanoff compares the politics and policy of the life sciences in Britain, Germany, the United States, and in the European Union as a whole. She shows how public and private actors in each setting evaluated new manifestations of biotechnology and tried to reassure themselves about their safety.