Rather more than twenty years ago, on a spring morning of alternate cloud and sunshine, I acted as guide to Johan Huizinga, the author of this book, when he was on a visit to Oxford. As it was not his first stay in the city, and he knew the principal buildings already, we looked at some of the less famous. Even with a man who was well known all over the world as a writer, I expected that these two or three hours would be much like the others I had spent in the same capacity with other visitors; but this proved to be a day to remember. He understood the purposes of these ancient buildings, the intentions of their founders and builders; but that was to be expected from an historian who had written upon the history of universities and learning. What surprised and delighted me was his seeing eye.