This would be the only part of the work which is an unalloyed pleasure to write, were it not for the fact that in attempting to itemize one's debts, one cannot help but become conscious of the danger of sins of omission. Naming no names, therefore, my list of creditors includes my teachers at the London School of Economics who, a decade and a half ago, inspired me with an enthusiasm for the history of political thought and tried to show me how to study it, and my colleagues in the Department of Politics at Lancaster University, who sustained me during the long period of gestation, even those who regarded my project as an eccentricity to be indulged. Nominatim, my thanks go to my head of department, Gordon Hands, who has always seen his way to making the necessary funds available; to Mrs Elizabeth Wetton, who steered the book through Cambridge University Press; and to Mrs Lesley Magowan, who typed the manuscript with accuracy and cheerfulness. The two anonymous reviewers of Cambridge University Press and Professor J. G. A. Pocock in their various ways sought to protect me from myself. And if, in seeking to avoid the gaffes and pitfalls they pointed out, I have fallen into a good many others, the fault will be mine, not theirs.