Many people contributed to the realization of this book. I am very much indebted to Hilary Gaskin and her team at Cambridge
University Press for their outstanding editorial help. This book would have been impossible without their friendly and professional
support and feedback. The authors are to be congratulated for their excellent chapters, and thanked for the constructive patience
they exercised against what must have seemed sometimes like editorial harassment. I am most grateful to all of them for their
intellectual contributions. Penny Driscoll, my personal assistant, provided vital help in editing the final bibliography and
other parts of the book. The anonymous referees offered some excellent input, which proved very valuable. Finally, I owe to
Kia, my wife, the environmental happiness within which this book developed. Without her, some editorial problems would have
turned into nasty troubles instead of exciting challenges.