How is love different from lust or infatuation? Do love and marriage really go together "like a horse and carriage"? Does sex have any necessary connection to either? And how important are love, sex, and marriage to a well-lived life? In this lively, lucid, and comprehensive textbook, Raja Halwani pursues the philosophical questions inherent in these three important aspects of human relationships, exploring the nature, uses, and ethics of romantic love, sexuality, and marriage. The book is structured in three parts: Love begins by examining how romantic love differs from other types of love, such as friendship and parental love. It asks which properties of love are essential, whether people have a choice in whom they love, and whether lovers have moral obligations to one another that differ from those they owe to others Sex demonstrates the difficulty in defining sex and the sexual, and examines what constitutes good and bad sex in terms of pleasure, 'naturalness', and moral permissibility. It offers theoretical and applied ethical approaches to a wide range of sexual phenomena Marriage traces the history of the institution, and describes the various forms in which marriage exists and the reasons why people marry. It also surveys accounts of why people should or should not marry, and introduces the main arguments for and against gay marriage. Features include: suggestions for further reading online eResource site with dowloadable discussion questions a clear, jargon-free writing style.