And so, after Blueprint for a Cell, which came out, I think, in '91, I wrote a book that, in a way, I thought maybe my last one. I always say the last one is the last one. This I called Vital Dust. And Vital Dust is... is more addressed to the lay public. I mean, it's still rather... it's tough reading for the lay public, it's maybe a little too easy for the scientist, but, anyway ,Vital Dust went one step further. In Vital Dust I not only discussed the origin of life, but I discussed also evolution up to the onset of... of mankind. So to write that book I had, again, to do an enormous amount of reading and studying and learning. So, to me, writing these books has been particularly gratifying because it's been a learning experience all the time and I found that very enriching. Anyway, so I had to learn about evolution of life. I had to learn something about plants which I knew nothing about and... and so on, and also about the origin of man. And the subtitle of Vital Dust is Life As a Cosmic Imperative. So I'd begun to... to formalise my thinking on the subject and one of the conclusions which most... most experts agree on is that life, being a chemical process, was bound to... to start under the conditions under which it started. It's chemistry so it's deterministic; it's obligatory under the conditions. So life is a cosmic imperative to the extent that the conditions for... needed for life to arrive are obligatory and the odds are that they not only occurred on... on Earth but maybe in other planets in the universe and this has become, today, a question of major interest. Nobody knows the answer but many people are now looking for signs that there may be extraterrestrial life. So Vital Dust goes beyond even the advent of humankind. I'm not sure that I forget... I remember that the book was divided in... in seven ages – just like the stone age, the iron age. I think the first one was the age of information, then the age of chemistry... sorry, age of chemistry first, age of information, then the age of the cell, multicellular organisms, man – humans, I'd better say – and the seventh age was the age of the future. And so I was beginning to look into what are the prospects.