A.N. Whitehead and Henry Sidgwick are two of the most influential thinkers on matters of ethical theory and application in the 19th and 20th centuries. They are also two of the most overlooked. This book examines their contributions in the field of philosophy. Sidgwick and Whitehead both present fairly comprehensive examinations of ethical and quasi-ethical theories ranging from egoism to utilitarianism in many forms, to Kantian deontological views and theistic intuitionism of Samule Taylor Coleridge and the Cambridge Moralists.