For reasons explained at the end of the introduction, I began this book about ten years ago; I continued it because a number of friends and colleagues encouraged me to think that it would be useful. My first debt is to the late Charles Schmitt, who saw parts of the work in its earliest form and first put me in touch with Cambridge University Press. Others who have read the typescript in whole or in part – Michael Allen, Tony Grafton, Brian Murphy, Doug Parrott – have given me important advice and criticism for which I am most grateful. Librarians and other staff at Oakland University and the University of California, Riverside, have also been most helpful. Though I do not know the names of the three generous and perceptive readers who examined and corrected the typescript, I wish at least to thank their nameless genii for rescuing me from ignorance or imprudence in more cases than I can comfortably contemplate. My more public thanks go to Kevin Taylor and Jonathan Sinclair-Wilson, who handled the project for Cambridge with patience and skill. Patience, long-suffering patience, has also been the chief virtue of my wife, Kathleen, and my children, Gregory and Rebecca, while I was lost in the temples of Hermes. My son, in particular, may at last be convinced, when he sees the book in print, that it was others and not I who invented the myth of Hermes Trismegistus.