And I started very cautiously approaching the philosophical aspects. Maybe not really religious but philosophical aspects of this whole saga of life – 4 billion years almost of life on this planet starting with very simple forms of life and evolving slowly into the first eukaryotic cells and then quite late the first multicellular organism, the plants, and only 600 million years ago the animals, and only 6 million years ago the beginning of the last chapter leading to human kind... only 200,000 years ago. Very recent. And so I began to ask: what does this mean? Is this meaningless or does it have a meaning? That's a philosophical question, and there was... the meaninglessness of everything was very much a popular kind of thinking, some years ago. Jacques Monod wrote his famous book, Chance and Necessity, which appeared 35 years ago. And in the book – I know it almost by heart – he says, for instance, ‘The universe was not pregnant with life.’ Just different from what I said, a cosmic imperative. ‘The universe was not pregnant with life nor was the biosphere pregnant with man’, and then he ends the book with this beautiful sentence: ‘Man knows at last that he is alone in the unfeeling immensity of the universe.’ And Steven Weinberg, a very well known physicist in the United States, says the same thing. He's in an aeroplane... I forget exactly what he writes – he looks down and he thinks about the meaninglessness of it all. And this went together with, well, existentialist philosophy of the '60s – Sartre and Camus and so on: everything is absurd; there is no meaning. And I've never been – perhaps not intellectually, but sentimentally – very sympathetic to that kind of thinking and to me the existence of life and the existence of mind, obviously, are meaningful. I mean, there are properties that are so remarkable and so extraordinary that they do mean something about what the universe is all about. And so Vital Dust ends on that kind of note and also on a note of warning for the future because of this very recent event in the history of life, the last millennia, not many millennia, the advent of living beings that have developed a brain – a mind sufficiently advanced to be able to understand the nature of life, their own nature... not only to understand but to manipulate life at the present time which implies a tremendous responsibility, a cosmic responsibility, or at least planetary responsibility for all the future of life on Earth and the future of humankind. This may be another 5 billion years before the Earth becomes definitely uninhabitable because the Sun is going to explode and burn us all to a cinder, but 5 billion years is more than the whole history of life until now, so anything can happen in the... the future and the difference is that for 4 billion years, what happened was ruled by natural selection, and suddenly with the advent of... of man, it's not only natural selection alone – it's still active, but it is also what we as a species are going to do, and obviously what is happening right now doesn't inspire tremendous optimism in the future. We may... we may have all the intelligence that is needed to do all that we do but natural selection may have privileged intelligence for all kinds of reasons that we can think of, but it may... it may well not have privileged the wisdom needed to manage the fruits of the intelligence. So this has become for me a major thought and all this led to another book.