I have several conflicting thoughts on this book. For one, I think Masson is quite brave to attempt writing about the emotions of a different species. Emotions are so individual and diverse even among different people (much like colors... your definition of "angry" may be quite different from my definition of "angry"), that to try interpreting the emotions of a different species without letting one's own personal filters interfere with the observations is nearly an impossible task.
My one major bone to pick with this book has to do with some behavioral observations that were interpretted by Masson as facts. For instance, Masson notes that cats only purr when around others (and dogs only wag their tail in relation to other animals or people). However, without hours of observation through videocamera/tape recordings, he has no way to back up this "fact". Many other observations bugged me in pretty much the same way - I would have been much happier overall with this book if he had quoted some scientific studies (or even just gone into detail with more observational data). I also would have liked to see this subject carried further by tracking the cats through more than just their first year of life. We don't expect the same emotional clarity from a two year old child (or an eighteen year old, for that matter) that we do from a middle aged woman. The same goes for dogs and cats - one year is not enough time for a cat to emotionally mature. My current cat, "Trouble", didn't truly seem to "grow up" until he was at least three years old.
Despite the vague subject matter and the non-supported observations, I did really enjoy a lot of this book and was entertained by the antics of Masson's pride of five. I do think I learned something from this book, but could perhaps have learned even more with a bit more depth.
For cat lovers and other pet owners.
A MUST read for any cat owners or cat lovers. Helps you understand even the strangest behavior of these creatures. Enjoyable