Book excerpt: Christian philosopher Robert Spaemann takes the reader on a quest for the fundamental principles of ethics. Writing in a clear style accessible to non-specialists, drawing both on ancient and modern philosophy, from Aristotle, Plato and Aquinas to Kant and Hegel, he discovers the intimate relationship between ethics and ontology - the science of being. This book is written for theologians as well as philosophers - indeed for anyone who is concerned with the meaning of a 'life well lived', with good and evil and the search for happiness.