Acknowledgements
This book has its origins in work undertaken, at Sheffield University, for a PhD thesis which was completed in 1984 and I would like to thank the many members of staff who, in formal and informal discussion, helped to shape the present work.
I am greatly indebted in particular to Roy Houghton of the Department of Economics who suffered the many iterations of this book and provided constructive criticism with unfailing g∞d humour. I am also indebted to the late Peter Nidditch whose clear and rigorous thinking I shall always admire, and to Rolf Gruner who gave help and advice in the early stages of this project.Thanks are also due to Donald Winch who generously spent a long day in discussing some of the issues raised in this book, and resolved some of the problems I then faced.
Finally my thanks to Ruth Barker for her painstaking efforts in typing the many revisions of the book.