This book should be called “The Philosophy of Sustainability.” It is about principles as in "these are my moral principles" as opposed to scientific principles … Interesting and in-depth analysis of different philosophical arguments and trains of thought that help build a fairly solid sustainability argument, or at least a strong point-of-view. More about discussion of different historical and philosophical viewpoints than any solid set of principles, but I found it immensely interesting and rewarding to read. If you start reading it knowing it is a philosophy book as opposed to a pragmatic, action-able "this is how we make things sustainable" book, you too will find it rewarding.
Long ago I read the first edition of this book. This edition is an updated one with several relevant facts. It was refreshing experience to re-read the book. A must read and a starting point for anyone venturing into sustainability studies.