I'm a full time mediator and I also do a fair amount of mediation training. When I teach a mediation course at the university level, this is the book I use as the textbook. It's the most thorough and thoughtful work on mediation, mediation history, and how mediation works. It's the backbone of every training program I've attended as well as my own trainings. It's long and not for the casual reader, but it's a terrific value and very complete. If I had to recommend one book on mediation, this is it.