This book examines the central questions of ethics through a study of theories of right and wrong that are found in the great ethical works of Western philosophy. It focuses on theories that continue to have a significant presence in the field. The core chapters cover egoism, the eudaimonism of Plato and Aristotle, act and rule utilitarianism, modern natural law theory, Kant's moral theory, and existentialist ethics. Readers will be introduced not only to the main ideas of each theory but to contemporary developments and defenses of those ideas. A final chapter takes up topics in meta-ethics and moral psychology. The discussions throughout draw the reader into philosophical inquiry through argument and criticism that illuminate the profundity of the questions under examination. Students will find this book to be a very helpful guide to how philosophical inquiry is undertaken as well as to what the major theories in ethics hold.