In thanking my colleagues who have been kind enough to write essays for this volume, I have to offer them, first, a substantial apology. It was always the design of this book that I should contribute a ‘reply’, and I welcomed that opportunity. Some volumes in the Festschrift format display a rather ghostly quality from the absence of their honorand: the person in whose name the guests have come is not at the party, and that must either be an insult, or be glumly explained by the party's being a wake. However, my enthusiasm at this idea was not matched by speed of delivery, and I have, by dilatoriness, condemned my friends to waiting a frustratingly long time to see in print what they amiably wrote in my honour and for my comment. The explanation does not lie in indifference to their thoughts about my work – rather, the reverse. I can only say that I am sorry, and that I hope that they will not feel that their gift to me has been spoiled.

As the editors have said in their Introduction, it was not the plan that I should comment on all the contributions one after the other or in equal detail. I have taken up papers, or parts of papers, on which I thought I had most to say, whether in explaining or correcting what I originally wrote, or in developing some suggestion.