Over the past months I have received a lot of encouragement from many people who were keen to see this book in print. This was a great help to me, since I have more than once regretted having taken the task on in the first place. I hope that the final result will justify the work that so many people have put into it.

I wish to express my thanks to all those who, by their painstaking work, have made the appearance of this book possible. In the first place, my thanks to Mick Brooks for his invaluable help with the section on economics and expert proof-reading, and to Harry Whittacker, Jordi Martorell and Fred Weston, for their proof-reading and valuable suggestions. I must also thank Harry Nielsen, Luke Wilson and Alex Grant for their helpful observations on the chapter on science. In addition, I would like to thank Espe Espigares for her professional layout.

Since we decided to publish the book simultaneously in English and Spanish, I would also like to thank Juana Cobo and Pablo Roldán for the excellent Spanish translation. In addition, a special mention is due to Miguel Fernández, whose considerable literary skills were of great help to me in perfecting and polishing the final text both in Spanish and English.

Above all, my heartfelt thanks to my comrade and companion Ana Muñoz for her invaluable help and encouragement, and for her immense patience in the final proofreading, which was enough to try the patience of a saint!