Very nice chart! I'm currently trying to get as many religions in my capital as possible with Saladin. I'm expecting a great prophet from Stonehenge. I can see here that if I can research priesthood, I can get theology and divine right out of prophets (I have all the lower techs researched). Guess I'll have to research code of laws myself.
Very helpful, thanks!
P.S., I take it you can get the tech through the GP lightbulb even though you don't have the prerequisites?