1200s France, Esoteric Heresy As Viral Epidemic within Scale-free Networks
For a period around 1200 - The Southern French Cathar heresy occupied territory and created a Esoteric Radical Cultural Zone in which Troubadors Poets, and Christian and Jewish mystics flourished. I would argue that the Cathar Heresy created a kind of proto Burning Man Libertarian Zone which gave cover to the Kabbalah studies that emerged here and in Catolonia and Castille. Ironically both Esoteric Social Movements can be traced back to the Esoteric Gnostic/Platonic/Pythagorean/Hermetic/Jewish/Christian/Pagan melting pot of Roman Egypt from 100-300 C.E. For more information of The Cathars see this book.
The following paper gives a very interesting historical analysis of Heresy as a Viral Epidemic.
The Medieval Inquisition: Scale-free Networks and the Suppression of Heresy
Paul Ormerod and Andrew P. Roach 2003
