This was a fascinating book. I was initially intrigued by the premises, the idea that humanity from the future is somehow influencing the events of the present. That’s actually a lot simpler than the actual hypothesis of the book, but it’s a decent generalization. The book is intelligent and certainly gives the reader a lot to think about.
Butler starts with some of history’s greatest mysteries. Monuments that could not have possibly been built with the technology held at the time. Things in history that currently have no substantial explanation. One of my favorite chapters dealt with a UFO sighting that took place over the course of several weeks outside a military outpost. The prevalent explanation at the moment is aliens came to our tiny planet and made the necessary adjustments in earth’s history and then just left, leaving nothing behind. Butler disagrees with this theory for the most pressing reason of that it would take far too long for any alien species to get here. The nearest star is simply too far away to make interstellar travel practical. No intelligent species would make such a long journey to our planet to help out our budding system of humans and just leave. It simply wouldn’t be practical for a species to make that type of investment and take away no gain. Humans from the future, on the other hand, they have a legitimate interest to be concerned with the past of their own selves.
Butler also explains how to get around the time paradox, how visitors would only be able to access a certain point that they had already visited in the past. He also says how it’s quite possible that people from the future have inserted communication devices inside people of the past who seemed to have had an advanced intellect for their time. For instance, think of all the things Da Vinci could have done if he had not been constrained by the technological limitations of his own era. At this point, however, he starts to fall victim to his own ego and thinks he is the most important thing to happen in the time-space continuum. You would almost think he was responsible for the time travel that allows his theory to be true.
There was one other aspect of the book I did not enjoy, however. Towards the end, Butler seems to constantly make a point of telling readers that some of the theories he is expressing are explained in further detail in one of his other books. By the end of this book, almost all of his other books have been mentioned as further reading at least once. While I appreciate the effort to provide additional material for the readers, at times it feels like the last third of the book is nothing more than a shameless plug for all his other books. Yes, it’s wonderful that he’s done such extensive research into these subjects. But I’m not reading those books. I’m reading this book. Please stop wasting space in this book trying to get me to read your other books. Focusing more on the present book will make more inclined to read your other books.