This work has filled and extended my life over several years. During that time I have been continuously grateful for the resources of the Cambridge University Library, the English Faculty Library, and the Girton College Library, and for the helpfulness of their librarians.

The English faculty office has come to my aid from time to time by typing draft sections and I would like to thank all the members of staff. Dr Jenny Fellows, and members of my family, have read proofs and checked references. Historians and philosophers of science as well as my colleagues in literary studies have been most kind in inviting me to try out my ideas in discussions, seminars, and lectures. I could not have completed the work without the stimulation of friends working in a variety of fields who have been generous of their knowledge, offering me references to pursue, arguments to consider, and scepticism to combat. It is hard to name a few among so many individuals to whom I feel gratitude, but I would particularly mention the importance of conversation over the years with John Beer, Jina Politi, Sally Shuttleworth, Allon White, and Ludmilla Jordanova. More recently, Howard Gruber, David Kohn, Mary Jacobus, and George Levine have offered invaluable help. Gordon Haight and Barbara Hardy have been of help to me since the beginning of my career and, like all those engaged with George Eliot, I am indebted to them for their work.