Utilitarianism ? a philosophy based on the principle of the greatest happiness for the greatest number of people ? has been hugely influential over the past two centuries. Beyond ethics, utilitarian assumptions and arguments abound in modern economic and political life, especially in public policy. An understanding of utilitarianism is indeed essential to any understanding of contemporary society. Understanding Utilitarianism presents utilitarianism very much as a living tradition. The book begins with a summary of the classical utilitarianism of the eighteenth and nineteenth centuries while subsequent chapters trace the development of the central themes of utilitarian thought over the twentieth century. Questions covered include: What is happiness? Is happiness the only valuable thing? Is utilitarianism about acts or rules or institutions? Is utilitarianism unjust, or implausibly demanding, or impractical? Where might utilitarianism go in the future?