This book provides a summary, critique and comparison of the most important theories on how metaphors are used and understood, drawing on research from linguistics, psychology and other disciplines. In order to ground the discussion in actual language use, the book uses examples from discourse, including casual conversations, political speeches, literature, humor, religion and science. Written in a non-technical style, the book includes clear definitions, examples, discussion questions and a glossary, making it ideal for graduate-level seminars.