This volume is, and is not, a collection of essays. It is a collection in the sense that the volume is in large part based on articles already published or in press, but I hope it is more than ‘merely’ a collection. This is so both because I have not simply included these essays just as they were but have revised and integrated them, or in some cases only parts of them, and also because I regard them as from the start a coherent body of work. The unifying themes and the ways in which one essay builds upon another will, I think, be more or less self-evident, though in the Introduction there are some general reflections on the dominant themes and their historical context, as well as some comments on what I have done to the essays for the purposes of this volume. Here, I simply wish to thank all the original publishers and the many people who have, in one way or another and at one time or another, helped me with one or more of the chapters.