Ninja seem to have sprung up in proto-democratic communities. Is there something fundamentally subversive about ninja?
I wouldn’t say subversive. If you can imagine self-defense communities that needed places to retreat to in case of attack — there are still several dozen, perhaps hundreds of places where they used to gather. These are earth mounds, similar to the Celtic forts in southwestern England. These are not well researched, and the archaeology still has to be done. They are pretty unique to Iga and Koka. They never had the sort of castles that are typical to much of Japan nowadays, which are tourist attractions and much restored. These places have not been restored and are often covered with trees. So there’s a lot of work to be done about the ninja and how they operated.
Were these forts defended by armies of ninja?
Nobody knows. The manuals that were written do not talk about cooperative activities at all. They were always treated as individuals. They must have operated as groups, but there’s no records of them doing so.