For the serious James scholar, this book is indispensible. For those of you who are not too familiar with Jame's ideas and their background, this book is probably too much - and too boring at that. Even for scholars of epistemology, this book can be rather frustrating. Originally written for his grad students at Harvard, the book lacks much in the way of context, and it is completely theoretical. Furthermore, it is filled with many untranslated passages, from German to Latin. I gave the book four stars because it could use some editing. This is the modern era: Latin is dead - even for the most serious philosopher - and German is no longer the language of Philosophy. The passages should be translated, and some of the more abstract essays should come with introductions. That said, the book is still a valuable contribution to empirical epistemology, laying out James of view of "radical empiricism" - where subjects and objects collide. Indeed, the book itself is a pure experience!