Prepared and co-published by the National Catholic Bioethics Center in Philedelphia, this book is a combination of two lengthy essays written by Cardianl Ratzinger and delivered in talks when he was the head of the Congregation for the Doctrine of the Fatih. Both talks deal with the importance of conscience and its exercise in particular circumstances. Ratzinger's reflections show that contemporary debates over the nature of conscience have deep historical and philosophicsl roots. He say that a person is bound to act in accord with his conscience, but he makes it clear that there must be reliable, proven sources for the judgement of conscience in moral issues, other than the subjective reflections of each individual.