When Stanley Kubrick was working on the development of his classic movie, "2001: A Space Odyssey", he arranged that twenty-one of the leading scientists in the world be interviewed on film, to speculate about their ideas on life in the universe and the impact its discovery would have on us. He wanted to cut into the movie, alongside the narrative, snippets from the interviews. Eventually, he discarded the idea and the interviews were never used. When it came time to issue a celebratory DVD of Kubrick's masterpiece, there was a suggestion that the interviews could be issued as part of the disc set. Alas, the film could not be found and it appeared that all had been lost, perhaps mis-filed in some dusty archive or else, sadly, even destroyed. However, four foolscap ring-binders containing the typed transcripts of the interviews were discovered and these make the basis of this remarkable book. All those interviewed were or have become major international figures in their fields. Aleksandr Ivanovich Oparin wrote what has been described as the first and principal modern appreciation of extraterrestrial life. Harlow Shapley was one of the finest American astronomers and someone to whom we owe our understanding of the size and shape of our galaxy. B. F. Skinner was renowned for his work on behavioural conditioning. Margaret Mead was the most famous anthropologist of her generation. Frank D. Drake pioneered SETI and formulated the Drake Equation. Fred Whipple might well be considered the great astronomer of the twentieth century. And these are just six names taken at random. The whole collection represents a brilliant over-view of scientific, philosophical and ethical considerations of the implications of the possibility of other forms of life within the universe. And the comments are as potent now as they were nearly fifty years ago.