I read about an American professor that was visiting the various cathedrals in France and started noticing that the stained glass windows were interweaving the

I read about an American professor that was visiting the various cathedrals in France and started noticing that the stained glass windows were interweaving the parable of the good samaritan with the story of the garden of eden in a fairly consistent manner. He didn't understand why they were doing that until he found records of medieval sermons explaining why they were combining these two stories. It was a symbolic message that would have made sense to medieval peoples, but had been lost over the intervening centuries.