Human genetic enhancement, examined from the standpoint of the new field of political bioethics, displaces the age-old question of truth: What is human nature? This book displaces that question with another: What kind of human nature should humans want to create for themselves? To answer that question, this book answers two others: What constraints should limit the applications of rapidly developing biotechnologies? What could possibly form the basis for corresponding public policy in a democratic society? Benjamin Gregg focuses on the distinctly political dimensions of human nature, where politics refers to competition among competing values on which to base public policy, legislation, and political culture. This book offers citizens of democratic communities a broad perspective on how they together might best approach urgent questions of how to deal with the socially and morally challenging potential for human genetic engineering.