lism presented for the degree of Ph.D. to the University of
London in 1954, it does not represent a reworking of that thesis,
but is a completely separate book. However, I would like to take
this opportunity of thanking Professor W. A. Robson, and Mr.
R. H. Pear of the London School of Economics, and Dr. S. R.
Davis, now of the University of Queensland, for the help which
they gave me during the preparation of that thesis. Several people
were good enough to read all or part of the present work, including
my colleagues at the University of Exeter, Andrew Dunsire and
W. S. Steer, and also Mr. Colin Leys of Balliol College, Oxford,
and I am grateful for their comments. Professor E. V. Rostow,
Dean of the Yale Law School, was kind enough to read part of the
manuscript, and I found his suggestions most helpful. I am parti-
cularly grateful to Dr. K. C. Wheare, Rector of Exeter College,
Oxford, for his encouragement, as the work falls in a field of
knowledge which he has made peculiarly his own.

Above all I wish to thank my wife, Margaret, whose help in in-
numerable ways all through the preparation of this book was the
decisive influence in ensuring that it was finally completed.

M. J.C.V.

Leverett, Massachusetts.
March, 1961.

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