In , Richard Sorabji brings his erudition and philosophical acumen to bear on a fundamental question: what is conscience? Examining the ways we have conceived of that little voice in our heads--our self-directed judge--he teases out its most enduring elements, the aspects that have survived from the Greek playwrights in the fifth century BCE through St Paul, the Church Fathers, Catholics and Protestants, all the way to the 17th century's political unrest and the critics and champions of the eighteenth to twentieth centuries. Sorabji examines an impressive breadth of topics: the longing for different kinds of freedom of conscience, the proper limits of freedom itself, protests at conscience's being 'terrorized, ' dilemmas of conscience, the value of conscience to human beings, its secularization, its reliability, and ways to improve it. These historical issues are alive today, with fresh concerns about topics such as conscientious objection, the force of conscience, or the balance between freedoms of conscience, religion, and speech. The result is a stunningly comprehensive look at a central component of our moral understanding.