This book started out as a PhD thesis completed at University College London in 2001. The original intention of that PhD was to produce a new approach to understanding religious interaction in the fourth century ad by exploring the writings of Libanius and Chrysostom alongside one another. I hoped to gain access to processes of religious interaction in a way that is not usually possible for the ancient world by taking advantage of the fact that these two authors, from different religious traditions, were working and writing in the city of Antioch almost contemporaneously. The original project did not get as close to achieving this goal as I would have liked. Four years of post-graduate study was barely enough time to get to grips with the massive body of material provided by Libanius and Chrysostom, let alone to develop a new theoretical model for understanding what their writings tell us about religious interaction. When I began to think about turning the PhD into a publishable book, it very quickly became clear that a lot more work was needed in order to make my study match the claims I was making for it. Over the last two years I have been engaged in this work and have tried to develop a strong theoretical grounding for ideas that previously had only embryonic form.