A friend should be able to be an attentive listener, which made semiotician Roland Barthes wonder in his intriguing dictionary of love, "cannot friendship be defined as a space with total sonority?". This volume takes on the encyclopedic task - in the sense of Umberto Eco, where an encyclopedia is a very complex sign - to explore friendship in detail, not only as a form of love but in all its complexity as a bond that connects people and forms communities. Semiotics, the study of signs and meaning-making, is used alongside insights from a wide range of friendship studies to create a far-reaching intellectual resonance, or sonority, around friendship as a central human experience. As a study of the significance of friendship, it presents findings from friendship research across the globe, enabling new ways of thinking about friends. It includes: key concepts from semiotics, sociology, anthropology, and other fields, briefly explained major models of friendship from antiquity to contemporary societies proverbs and sayings about friendship from Africa, America, Asia, and Europe stories about famous or forgotten friends from mythology, fiction, and real history summaries of research on friendship from selected academic disciplines bibliographical references for further studies