I have rated this book 5 full stars, although to be fair I'm very interested in the subject matter and I may be looking past what other readers might be turned off by in order to facilitate the recognition of what is an excellent answer to the proposition of this book. That is: What is transhumanism, and where did this dangerous idea come from?
Let's start with "the bad." Some may be very turned off by Livingstone's rather brave approach to leave no stone unturned. This may have two negative effects on the reader:
1. They will dislike the sheer exhaustive nature of this book, rather than seeing it for the comprehensive tome that it is, and...
2. They may well be very offended by the inclusion of a famous person they like (i.e. an author, scientist, or pop star/etc) that has been included as a "transhumanist," rather than viewing their inclusion as a legitimate entry that--regardless of our feelings about their work/impact--may actually be very relevant to the thesis of Transhumanism. I know this happened to me more than once while I read this book.
Additionally, the "dangerous" or otherwise negative nature of the transhumanism exhibited by individual entries here might be debated as well. But I think Livingstone did very well to be as inclusive as he was here. While some entries might seem a little bit extraneous, it makes for a more interesting read than other books on the topic which paint in much broader strokes or focus on detailing a specific time period. This book does it all.
Personally I was very impressed with this book and many individuals he mentioned might not have felt transhumanist prior to my reading this book but after reflecting on the author's evidence I can say that I have realized that he was right to include them. For one example, I never realized that the Beatnik or Psychedelic movements had so much overlap with transhumanist themes and I was quite resistant to the idea at first. But, much like anything, we have to realize that we won't always agree with every aspect of our personal favorite auteurs' mindsets or muses. We also should learn to be less offended at a studious author like Livingstone "killing our darlings" in such a way as the mere mention of connecting some of these figures to the concept of transhumanism is not necessarily a terrible thing in of itself. But it does make for some fairly deep contemplation as one might realize just how deep this could, or does indeed, go.
In any case, I don't really believe in the 5-star rating system it's just a way to convey enthusiasm for a given book really. Books like this deserve better than that because they bring our attention to important subject matter that seems to get glazed over elsewhere and this book is absolutely not for someone looking for a light fun read that doesn't challenge them on some level. But with that said, if you are looking for a fairly exhaustive book chronicling the existence of transhumanism throughout many different time periods and socio-political/artistic movements, including many that are not completely obvious to people who have spent some time with this subject ...I honestly don't think you'll do better than This Book. Cheers fellow curious readers!