Today we consider ourselves to be free and equal persons, capable of acting rationally and autonomously in both practical (moral) and theoretical (scientific) contexts. The essays in this volume show how this conception was first articulated in a fully systematic fashion by Immanuel Kant in the eighteenth century. Twelve leading scholars shed new light on Kant's philosophy, with each devoting particular attention to at least one of three aspects of this conception: autonomy, freedom, and personhood. Some focus on clarifying the philosophical content of Kant's position, while others consider how his views on these issues cohere with his other distinctive doctrines, and yet others focus on the historical impact that these doctrines had on his immediate successors and on our present thought. Their essays offer important new perspectives on some of the most fundamental issues that we continue to confront in modern society.