In all my years of thinking about the various types of emotions and how best to characterize their differences, as well as my thinking about the nature of surprise, I have never been able to be as insightful, as profound, and as rigorous as these two authors are in this book. What they have done is not only unique, it is brilliant. As I read it, I stopped worrying about whether I agreed with them that this or that mental state is or isn't an emotion. Instead, I realized that sometimes it doesn't matter-that what matters is that there is a family of interesting and psychologically important, related states that we need to understand, regardless of how we categorize them. To make a die-hard purist like me ignore my prejudices is quite an achievement, and yet I feel all the better for it-indeed, almost liberated! Quite simply, this is wonderful, compelling book for which I heartily congratulate my friends, the authors. I loved reading it; I wish I had written it.