Contrary to some of the more critical reviews, the title does say "*thoughts* on humans and other animals". Read as a collection of thoughts and polemics, this is a greatly stimulating book. Some of the ideas are not as fully substantiated as they could be expected to be in an academically published book, but this is not a formal thesis or paper. It is a collection of thoughts from a man who does not presume to offer many answers, but asks, often using your own head, some very very good questions. I read it in the same week as Robert Pirsig's 'Lila' (one point I'd love to ask Gray if I ever met him is about novels written by philosophers, but I suspect we'd get tracked into definitions...), and the combination was fascinating. Why 4 stars? I did not love it - it is not a set of questions that are lovely. I liked it enormously and will no doubt re-read as a whole and in bits over time. Thankfully I was not put off by the blurbs of the left-liberal establishment figures who have raved about it.