http://arxiv.org/ftp/cond-mat/papers/0306/0306031.pdf

During the Medieval Inquisition, the Roman Catholic Church regarded heresy as a disease. This paper talks about heresy in 13th and 14th century France.

According to this paper, the Catholic Church noticed how the spread of heresy was like a disease spreading throughout Christendom. Leaders of the church likened heresy to rotting food, disease among livestock and plagues that cursed man. At first the church tried to wipe out heresy through intimidation. Intimidation later turned into the mass killing of populations. The church took the attitude of “We’ll kill them. Let God sort them out.” The church noticed that even though they were punishing massive amounts of people, the ones who escaped were helping spread heresy even more. These individuals were highly connected allowing them to evade capture and spread heresy.

The church decided to change their focus to these highly connected individuals. “Heresy hunters” would interrogate prisoners asking them what other heretics they associated with, in what sense did they associate, and what times they had known each other. From this information the church was able to target the most connected individuals. When the heretics were captured, the church would force them to publicly repent for not following Roman Catholic doctrine. The church hoped that this public display of repentance would slow the spread of heresy. Later the church changed punishment to a kind of solitary confinement so that heresy would not spread. This greatly disrupted heresy networks.

Heresy spread quickly across countries much like a contagious disease. Even when heresy was believed to have been wiped out, it would come back again and again. Mass inoculation (mass murdering) was unsuccessful is stopping this disease (heresy). It was only when data was gathered, a strategy was developed, and connected individuals were targeted was the church able to slow down the spread of heresy.