The Idea of Human Rights: Four Inquiries Book

I'm slightly unsure on how to properly rate/critique a piece that isn't fiction or a creative work, but I'll do my best.

I read this book for a human rights course, and as a student, I found that the questions Michael Perry brought up were fundamental to building a foundation of any theory of human rights. However, sometimes the points he made when addressing the questions were difficult to follow because he repeated himself quite a bit. I also disagreed with his stance in the first chapter ("Is the Idea of Human Rights Ineliminably Religious?"). His view is very biased in the beginning (and he does address it), but he does make some good points (when you understand them). In general, my rating is based on the execution/way it was written more than the actual content. I will add, however, that about a third of this book is footnotes/citations, so while it is clear that he did his research, I do question the originality of the work.